chapter 15 diseases resulting from fungi and yeasts andrews’ diseases of the skin joanne m. larow,...
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Chapter 15Chapter 15Diseases Resulting Diseases Resulting
from Fungi and Yeastsfrom Fungi and Yeasts
Andrews’ Diseases of the Skin
JoAnne M. LaRow, D.O.
Superficial mycoses AKA dermatophytes Classified into three genera: Microsporum, Trichophyton,
Epidermophyton Mycoses caused by dermatophytes are called dermatophytosis,
tinea, ringworm On certain parts of body tinea has certain features characteristic
of that site Hence the division into seven types (1)tinea capitis, (2)tinea
barbae, (3)tinea faciei, (4)tinea corporis, (5) tinea manus, (6) tinea pedis, (7) tinea cruris, (8)onychomycosis
Superficial mycoses can be divided into causative dermatophyte- Management is rarely assisted by ID of genus and species
Susceptibility They are soil saprophytes that have acquired ability to digest
keratinous material in soil, becoming “keratinophilic fungi” Some have evolved to parasitize keratinous tissues of
animals frequently in contact with soil and have lost their ability to survive in soil (zoophilic fungi)
Anthropophilic dermatophytes are believed to have evolved from zoophilic fungi, adapting to human keratin and losing their ability to digest animal keratin
Environmental conditions help promote propagation of many opportunistic fungi
Host factors are also significant
Host factors Immunosuppressed pts Pts with AIDS may have severe forms Genetic susceptibility to certain forms of fungal infections may be
related to types of keratin or degree or mix of cutaneous lipids produced
Surface antigens-ABO system-one study of 108 culture proven dermatophytosis pts noted that pts with type A blood were prone to chronic disease
Human steroid hormones can inhibit growth of dermatophytes (androgens like androstenedione)
One group believes this high susceptibility of Trichophyton rubrum & Epidermophyton floccosum to intrafollicular androstenedione is a reason why these species do not cause tinea capitis
Antifungal therapy
Consider spectrum of activity of antifungal Pharmacokinetic profile of the agent Clinical type of infection Additionally, safety, compliance and cost Griseofulvin is still therapeutic option but
studies are showing that newer antifungals are more efficacious
Imidazoles Clotrimazole, miconazole, sulconazole,
oxiconazole, and ketoconazole Mostly used for topical tx Inhibit cytochrome P450 14-alpha-demethylase (an
essential enzyme in ergosterol synthesis) Ketaconazole has wide spectrum against
dermatophytes, yeasts, and some systemic mycoses Ketaconazole has the potential for serious drug
interactions and a higher incidence of hepatotoxicity during long-term daily therapy
Allylamines Naftifine, terbinafine, butenafine Mode of action similar to thiocarbamates Inhibites squalene epoxydation Terbinafine has less activity against Candida species in vitro
studies then triazoles, but is effective clinically Terbinafine is ineffective in the oral tx of tinea versicolor but
is effective topically Few drug interactions have been reported, bioavailability is
unchanged in food, hepatotoxicity, leukopenia, severe exanthems, and taste disturbances occur uncommonly but should be monitored for clinically and by lab testing if continuous dosing over 6 weeks occurs
Polyene
Nystatin Irreversibly binding to ergosterol-an
essential component of fungal cell membranes
Triazoles Itraconazole Fluconazole Affect P450 system Numerous drug interactions occur Need to know pt’s current meds Broadest spectrum to dermatophytes and Candida species, and
Malassezia furfur Itraconazole is fungistatic-food increases its absorption , antacids
and gastric acid secretion suppressors produce erratic or lowered absorption
Pulse dosing limits concern over lab abnormalities Fluconazoles’s absorption is unaffected by food
Tinea Capitis
Occurs chiefly in children – less commonly in infants and adults
Boys more frequently than girls; except in epidemics caused by Trichophyton tonsurans where there is equal frequency
Divided into inflammatory and noninflammatory Tinea capitis can be caused by all pathogenic
dermatophytes except Epidermophyton floccosum and T. concentricum
In U.S. most caused by T. tonsurans(replacing Microsporum audouinii) & M. canis
Noninflammatory M. audouinii infections present as the classic form Characterized by multiple scaly lesions (“gray-patch”), stubs
of broken hair, and a minimal inflammatory response Occasionally glabrous skin, eyelids, and eyelashes are
involved Sometimes observed in epidemics in schools and orphanages Over past 30 yrs, M. audouinii infections are being replaced
by increasing numbers of “black-dot” ringworm, caused primarily by T. tonsurans and occassionally by T. violaceum
In the U.S. T. tonsurans is the most common cause
Tinea Capitis
“Black dot” ringworm, caused by T. tonsurans & occasionally T. violaceum presents as multiple areas of alopecia studded with black dots representing infected hairs broken off at or below the surface of the scalp
Black dot tinea
Black dot ringworm caused by Trichophyton tonsurans
Inflammatory Usually caused by M. canis Can be caused by T. mentagrophytes, T. tonsurans, M. gypsem,
or T. verrucosum M. canis infection begins as scaly, erythematous, papular
eruptions with loose and broken-off hairs, followed by various degrees of inflammation
A localized spot accompanied by pronounced swelling, with developing bogginess and induration exuding pus develops-kerion celsii
A delayed type hypersensitivity reaction to fungal elements With extensive lesions fever, pain, and regional
lymphadenopathy may occur
Kerion
Widespread “id” eruptions may appear concomitantly on trunk and extremities
These are vesicular, lichenoid, or pustular Kerion may be followed by scarring and
permanent alopecia in areas of inflammation and suppuration
Systemic steroids for short periods will greatly diminish the inflammatory response and reduce the risk of scarring
Kerion: inflammatory rxn of tinea capitis caused by Microsporum canis or Trichophyton mentagrophytes
Kerion caused by Microsporum canis
Kerion: heavily crusted, hairless plaque
Permanent scarring alopecia post kerion
Kerion: red, oozing, hairless plaque
Favus Rare in the U.S. Appears mainly on the scalp, but may occur on glabrous skin and
nails On scalp, concave sulfur-yellow crusts from around loose, wiry hairs On glabrous skin lesions are pinhead to 2 cm in diameter with cup-
shaped crusts called scutulae-usually pierced by a hair as on the scalp
Scutula have a distinctive mousy odor Nail involvement causes brittle, irregularly thickened, and crusted
nail changes Not seen typically in North America(has been reported in Kentucky
and Canada) Called witkop in South Africa by the Bantus
Favus of scalp showing scutulae
Scarring after favus infection
Etiology Tinea capitis can be cause by any one of several species: T.
tonsurans, M. audouinii, and M. canis First two are spread from human to human Latter is caught from animals such as kittens and dogs Most frequent invaders of scalp are endothrix types-T.
tonsurans(black-dot ringworm) and T. violaceum T. tonsurans alone affects adults(chiefly women) regularly;
others affect children Ectothrix found on scalp are T. verrucosum & T.
mentagrophytes (less frequently seen is T. megninii-southwest Europe)
Pathogenesis Incubation period lasts 2 to 4 days Hyphae grow downward into the follicle, on the hair’s surface,
and the intrafollicular hyphae break up into chains of spores Period of spread (4 days to 4 months) during which lesions
enlarge and new lesions appear At about 3 weeks hairs break off a few millimeters above the
surface Intrapilary hyphae descend to exact upper limit of keratogenous
zone and here form Adamson’s “fringe” on the twelfth day External portions of intrapilary hyphae segment into chains of
ectothrix spores
Pathogenesis No new lesions develop during the refractory period (4 months
to several yrs) Clinical appearance is constant-with host and parasite in
equilibrium This is followed by a period of involution in which the
formation of ectothrix spores and intrapilary hyphae gradually diminishes
Asymptomatic carrier states among young black children may occur
There has been a lack of correlation between number of asymptomatic carriers and index cases-suggesting that carrier cases are not primary mode of transmission of T. tonsurans
Histology
Extensive inflammation leading to follicular destruction
Medium power: dense inflammation consists of mixed cell types
Neutrophils and other inflammatory cells surround this small follicle.
Fungal elements are present within hair shaft
Diagnosis Ultraviolet of 365 nm wavelength is obtained by passing a
beam through a Wood’s filter composed of nickel oxide-containing glass
This apparatus a Wood’s light , is available commercially A simple form is the 125-volt purple bulb In a dark room the skin under this light fluoresces faintly
blue; however, infected hairs fluoresces bright green, beads on the hairs contrasting strongly with the dark field
Bare, scaly areas show a turquoise blue color Fluorescent-positive infections are caused by :M. audouinii,
M. canis, M. ferrugineum, M. distortum, T. schoenleinii
Diagnosis Hairs infected with T. tonsurans & T. violaceum and others of
endothrix do not fluoresce The fluorescent substance is pteridine For microscopic demonstration of the fungus, two or three loose
hairs are removed Hairs are placed on slide with a drop of 10-20% solution of
KOH A cover slip is applied, specimen is warmed until hairs are
macerated Examine under low, then high power Xylol is as satisfactory as KOH and need not be warmed Scales or hairs cleared with it can still be cultured
Diagnosis Fungus invades hair shaft in two ways-(1) ectothrix
involvement in which hair is surrounded with a sheath of tiny spores
Examples of these types are: Microsporum species, T. mentagrophytes & T. verrucosum (T. verrucosum is the fungus most frequently acquired by humans from cattle and causes a severe inflammatory tinea barbae in men or tinea capitis in children)
Other mode of infection is endothrix type-where arthrospores are formed inside the hair shaft
This type is seen in T. tonsurans, T. violaceum, and T. schoenleinii infections
Final and exact identification of causative fungus Such identification is largely epidemiologic and academic-tx is
the same Several infected hairs are placed on Sabouraud’s glucose agar
or Dermatophyte Test Medium (DTM) On DTM a distinctive growth appears within 1-2 weeks Diagnosis is usually made by gross appearance of culture When questionable the culture is examined under a microscope
for characteristic morphologic forms DTM contains antibiotics to reduce growth of contaminants and
a colored pH indicator to denote the alkali-producing dermatophytes
DTM
A few nonpathogenic saprophytes will also produce alkalinization and in the occasional case of onychomycosis of toenails caused by airborne molds, a culture medium containing an antibiotic may inhibit growth of the true pathogen
Cultures are best taken by rubbing the lesion vigorously with a sterile cotton swab moistened with sterile water and them streaked over the agar surface
Ectothrix type in Microsporum canis-note small spores around hair shaft
Endothrix spores in hair with Trichophyton tonsurans
Endothrix in T. scoenleinii showing characteristic bubbles of air
Endothrix infection, (low-power KOH mount): arthroconidia noted within hair shaft
Endothrix infection (high-power KOH mount) showing total hair shaft involvement
T. tonsurans
This microoraganism grows slowly in culture to produce a granular or powdery yellow to red, brown, or buff colony
Crater formation with radial grooves may be produced
Microconidia may be seen regularly Dx confirmed by the fact that cultures
grow poorly or not at all without thiamine
T. mentagrophytes
Cultural growth is velvety or granular or fluffy, flat or furrowed, light buff, white, or sometimes pink
Back of the culture can vary from buff to dark red
Round microconidia borne laterally and in clusters confirm dx within 2 weeks
Spirals are sometimes present Macroconidia may be seen
T. verrucosum
Growth is slow and cannot be observed well for at least 3 weeks
Colony is compact, glassy, velvety, , heaped or furrowed, and usually white, but may be yellow or gray
Chlamydospores are present in early cultures
Microconidia may be seen
M. audouinii
Gross appearance shows a slowly groing, matted, velvety, light brown colony
Back of which is reddish brown to orange Under microscope a few large multiseptate
macroconidia (macroaleuriospores) are seen Microconidia (microaleuriospores) in a lateral
position on hyphae are clavate Racquet mycelium, chlamydospores, and
pectinate hyphae are seen sometimes
M. canis
Culture shows profuse, fuzzy, cottony, aerial mycelia tending to become powdery in the center
Color is buff to ligth brown Back of colony is lemon to orange-yellow Numerous spindle-shaped multiseptate
microconidia and thick-walled macroconidia are present
Clavate microconidia ae found along with chlamydospores and pectinate bodies
Treatment Griseofulvin of ultramicronized form, 10 mg/kg/day, is the
daily dose recommended for children Grifulvin V is the only oral suspension available for children
unable to swallow tablets-dose is 20 mg/kg/day Tx should continue for 2-4 months, or for at least 2 weeks
after a negative microscopic and culture examinations are obtained
Griseofulvin does not primarily affect the delayed type hypersensitivity reaction responsible for the inflammation in kerion
For this, systemic steroids, to minimize scarring, can be given simultaneously
Numerous other studies exist that demonstrate the effectiveness of other oral agents, such as itraconazole, terbinafine, and fluconazole
These studies report these meds to be excellent alternatives, but the total reported experience to date is low
Selenium sulfide shampoo or ketaconazole shampoo three times weekly can be used as adjunctive therapy to oral antifungal agents
Herbert recommends culture of family members, caution regarding sharing potentially contaminated fomites, and simultaneous tx of all persons infected clinically or by culture
Drake et al recommend tx family members with ketaconazole shampoo, selenium sulfide shampoo, or povidine-iodine even if they are asymptomatic
Prognosis
Recurrence usually does not take place when adequate amounts of griseofulvin, fluconazole, or terbinafine have been taken
Exposure to infected persons, asymptomatic carriers, or contaminated fomites will increase the relapse rate
Without medication there is spontaneous clearing at about age 15, except with T. tonsurans which persists into adult life
Tinea Barbae
AKA Tinea sycosis, barber’s itch Ringworm of the beard Uncommon Occurs chiefly among those in agricultural pursuits Especially those in contact with farm animals Involvement is mostly one-sided on neck or face Two clinical types are: deep, nodular, suppurative
lesions; and superficial , crusted, partially bald patches with follicultis
Tinea Barbae
Superficial crusted type causes mild pustular folliculitis with broken-off hairs (T. violaceum) or without broken-off hairs (T. rubrum)
Affected hairs are loose, dry, and brittle When extracted bulb appears intact
Tinea Barbae Deep type develops slowly and produces nodular
thickenings and kerion-like swellings Caused mostly by T. mentagrophytes or T. verrucosum Swellings are usually confluent and form diffuse boggy
infiltrates with abscesses Overlying skin is inflammed, hairs are loose or absent, pus
may be expressed through the remaining follicular openings
Lesions are limited to one part of face or neck in men Upper lip is not usually involved, although mustache area
may be occasionally
Diagnosis-Tinea Barbae
Confirmed by microscopic findings of the fungus and by standard culture techniques for dermatophyte infections
Rarely, Epidermophyton floccosum may cause widespread verrucous lesions known as verrucous epidermophytosis
Verrucous epidermophytosis from Epidermphyton floccosum
Complete resolution after 48 days of griseofulvin
Differential Diagnosis
Sycosis vulgaris-lesions are pustules and papules, pierced in the center by a hair, which is loose and easily extracted after suppuration has occurred
Contact dermatitis Herpes infections
Tinea barbae-Trichophyton mentagorphytes
Treatment-Tinea Barbae
Oral antifungals are required Topical agents as adjunctive therapy Micronized or ultramicronized griseofulvin
orally: dosage of 500–1000 mg or 350-700 mg respectively
Tx usually for 4-6 weeks
Treatment-Tinea Barbae
Other orals that have been effective: ketoconazole, fluconazole, itraconazole, and terbinafine
Topical antifungals should be applied from the beginning of tx
Affected parts should be bathed thoroughly in soap and water
Healthy areas that are not epilated may be shaved or clipped
When kerion is present a short course of systemic steriod therapy may help reduce inflammation and risk of scarring
Tinea Faciei Fungal infection of the face (apart from the beard) Frequently misdiagnosed since typical ringworm is only
uncommonly seen on the face Instead, erythematous, slightly scaling, indistinct borders
are usually seen Diagnosis is easily established by direct microscopic
examination Usually caused by T. rubrum. T. mentagrophytes, or M.
canis Tinea faciei caused by T. nanum has been described in hog
farmers and should be considered an occupational source
Tinea faciei (Microsporum canis) in a child
Tinea corporis involving the face (tinea faciei)
Treatment
Topical clotrimazole, naftifine, micronazole, ciclopirox olamine cream, econazole, oxiconazole, ketaconazole, sulconazole, or terbinafine ususally bring about a prompt response
Oral griseofulvin administered for 2-4 weeks, as well as fluconazole, itraconazole, or terbinafine are all effective particularly in combination with topical therapy
Tinea Corporis(Tinea Circinata)
Includes all superficial dermatophyte infections of the skin other than those involving the scalp, beard, face, hands, feet, and groin
Sites of prediliction are neck, upper and lower extremities, and trunk
Can be caused by any dermatophyte Characterized by one or more circular, sharply
circumcsribed, slightly erythematous, dry, scaly, usually hypopigmented patches
Tinea corporis in a child, caused by Microsporum canis
Tinea Corporis Lesions may be slightly elevated, particularly at the border,
where they are more inflamed and scaly than at the central part Progressive central clearing produces annular outlines that
give them the name “ringworm” Lesions may widen to form rings many centimeters in
diameter In some cases concentric circles form rings in one another,
making intricate patterns (tinea imbricata) Multiple disseminated patches of both dry (macular) and moist
(vesicular) types of tinea circinata are encountered in which much of skin surface is involved
Widespread tinea corporis may be the presenting sign of AIDS
Tinea corporis (Trichophyton rubrum)
Note sharp margins and central clearing
Tinea corporis: large gyrate plaque with advancing border, perhaps worsened by diapering
Histopathology
Rarely the question of microscopic pathology may arise
Better ways to make diagnosis But if compact orthokeratosis is found in a
section, a search for fungal hyphae should be performed
This is diagnostic
Etiology-Tinea Corporis
Various organisms may cause this type of fungal infection
Microsporum canis, T. rubrum, T. mentagrophytes-most common
T. rubrum is is the most common dermatophyte in the U.S. and worldwide
T. tonsurans has experienced a dramatic rise as a cause of tinea corporis as it has for tinea capitis
In children, M. canis is the cause of the moist type of tinea circinata
Epidemiology
Tinea corporis is frequently seen in children-particularly those exposed to animals with ringworm(M. canis), especially cats, dogs and less commonly, horses and cattle
In adults excessive perspiration is the most common factor
Incidence is especially high in hot, humid areas of the world
Diagnosis-Tinea Corporis
Relatively easy via microscopic findings of fungus after skin scraping
Skin scrapings can be cultured on a suitable medium
Growth of fungus is apparent within a week or two at most and, most of the time is identifiable by gross appearance of the culture
Identification of the fungus is of epidemiologic interest, and is not helpful in managing the infection
Treatment-Tinea Corporis When tinea corporis is caused by T. tonsurans, M. canis,
T. mentagrophytes, or T. rubrum , griseofulvin, terbinafine, itraconazole, and fluconazole are all effective
The ultra-micronized form may be used at a dose of 350-750 mg once/day for 4-6 weeks
This dose may be increased to twice daily if needed Terbinafine, itraconazole, and fluconazole are effective Terbinafine at 250 mg/day for two weeks Itraconazole 200 mg B.I.D. for one week Fluconazole 150 mg once/week for 4 weeks
Treatment(cont) When only 1-2 patches occur, topical tx is effective Sulconazole (Exelderm), oxiconazole (Oxistat),
miconazole (Monistat cream or lotion, or Micatin cream), clotrimazole (Lotrimin or Mycelex cream), econazole (Spectazole), naftifine (Naftin), ketaconazole (Nizoral), ciclopirox olamine (Loprox), terbinfine (Lamisil), and butenafine (Mentax) are available and effective
Most are between 2-4 weeks with twice daily use Econazole, ketaconazole, oxiconazole, and terbinafine
may be used once daily With terbinafine the course can be shortened to 1 week
Treatment Creams are more effective than lotions Sulconazole may be less irritating in folded areas Castellani paint (which is colorless if made without
fuchin) is very effective Salicylic acid 3% -5%, or half-strength Whitfiels’s
ointment, both standbys 30 yrs ago, are little used today Addition of a low-potency steroid cream during the
initial 3-5 days of therapy will decrease irritation rapidly without compromising the effectiveness of the antifungal
Other Forms of Tinea Corporis
Trichophytic Granuloma or Perifollicular Granuloma or Majocchi’s Granuloma or Tinea Incognito
A deep, pustular type of tinea circinata resembling a carbuncle or kerion observed on the glabrous skin
A circumscribed, annular, raised, crusty, and boggy granuloma
Follicles are distended with viscid purulent material
Tichophyton mentagrophytes infection on lower leg of American soldier in Vietnam
Trichophytic Granuloma
Occur most frequently on shins or wrists Caused most often by T. rubrum or T.
mentagrphytes infecting hairs at sites of involvement Other dermatophytes have been reported:T. epilans,
T. violaceum, M. audouinii, M. gypseum, M. ferrugineum, and M. canis
In immunosuppressed pts lesions may be deep and nodular
Early on such a deep lesion may be pale, circular edematous plaque, often KOH- and culture-neg.
Majocchi’s granuloma occurs naturally in situations of occlusion or may be related to superficial trauma ie shaving
Diagnosis is made by demonstration of fungus via direct macroscopic potassium hydroxide slide and by culture or by clinical suspicion
Occasionally diagnosis is made on bx specimen Tx is same as for tinea corporis-except that even
that even for localized lesions oral therapy is needed
Majocchi’s granuloma H&E pale lue-staining fungal hyphae within hair shaft
Majocchi’s granuloma: PAS reveals multiple organisms that have replaced a fragment of hair shaft embedded in a sea of neutrophils
Tinea Imbricata (Tokelau) Superficial fungal infection limited to southwest Polynesia,
Melansia, Southeast Asia, India, and Central America Characterized by concentric rings of scales forming
extensive patches with polycyclic borders Eruption begins with 1 or several small, rounded macules
on trunk and arms Small macular patch splits in center and forms large, flaky
scales attached at the periphery Resultant ring spreads peripherally and another brownish
macule appears in the center and undergoes the process again
Tinea Imbricata
When fully developed the eruption is characterized by concentrically arranged rings or parallel undulating lines of scales overlapping each other like shingles on a roof (imbrex means shingle)
Causative fungus is T. concentricum TOC is griseofulvin- in same form as for tinea corporis Other options are terbinafine, fluconazole, and
itraconazole Several courses of therapy may be needed May need to remove pt from hot, humid environment
Tinea imbricata in New Guinea native
Tinea imbricata: concentric rings of scale caused by T. concentrium
Tinea Cruris AKA jock itch Most common in men On upper and inner thighs Begins as a small erythematous and scaling or vesicular and
crusted patch Spreads peripherally and partly clears in the center Characterized by its curved, well-defined border, especially at
lower edge Border ma have vesicles, pustules, or papules May extend downward on thighs and backward on the perineum
or anus Penoscrotal fold or sides of scrotum are seldom involved
Tinea cruris in a man
Tinea cruris in a woman
Etiology-Tinea Cruris
T. mentagrophytes & E. floccosum & T. rubrum usual cause
Infection with Candida albicans may closely resemble tinea cruris
Most useful distinguishing feature it posses are the regular occurrence of small “daughter” macules, centrally desquamating to form collarette scales, satellite pustules, scattered along the periphery of the main macule
Epidemiology &Tx
Heat and high humidity Tight jockey shorts, which prevent evaporation of the
increased perspiration produced during warm weather Tx: reduce perspiration and enhance evaporation from
crural area Keep as dry as possible by wearing underclothing and
trousers Plain talcum powder or antifungal powders are helpful Specific topical and oral tx is same as that described
under tinea corporis
Tinea in diapered area
Tinea of Hands and Feet Popularly called athlete’s foot Most common fungal disease(by far) Primary lesions often are macerated, slightly scaly,
with occasional vesiculation, and fissures between the toes
Most commonly the third toe web is involved Pt usually seeks relief because of itching If allowed to progress may lead to overgrowth of gram-
negative organisms Eventually leading to an ulcerative, exudative process
Tinea pedis showing interdigital scalping T. mentagrophytes
Interdigital scaling with vesiculation caused by T. mentagrophytes
Trichophyton mentagrophytes produces an acutely inflammatory condition
If invasion of skin of toes or soles, an acutely vesicualr or bullous eruption may occur
Vesicular eruption tends to spread by extension and unless checked, may involve the entire sole
Vesicles usually 2-3 mm in diameter-sometimes they coalesce to form bullae of various sizes
These are firm to touch and have a bluish tint They do not rupture spontaneously but dry up as the acute stage
subsides-leaving yellowish brown crusts Burning and itching of vesicles may cause great discomfort-relieved
by opening tense vesicles
Dermatophytosis of the soles
Trichophyton mantagrophytes
Acute vesiculobullous eruption on sole caused by Trichophyton mentagrophytes
Tinea Pedis Vesicles contain clear tenacious fluid the consistency of
glycerin Extensive or acute eruptions on soles may become
incapacitating Fissures between toes may become secondarily infected
with pyogenic cocci This may lead to attacks of lymphangitis and inguinal
adenitis Hyperhidrosis is frequently present Sweat on soles and in between has a high pH, and keratin
damp with a good culture medium for the fungus
TP-Trichophyton rubrum
T. rubrum causes the majority of cases
Produces a relatively noninflammatory type of dermatophytosis characterized by a dull erythema and prnounced scaling involving the entire sole and sides of feet
Producing a moccasin or sandel appearance
Tinea pedis and onychomycosis in father/son pair.
Father shows classic moccasin distribution of tinea pedis and son shows distal subungual onychomycosis
Tinea manus
Tinea infection of hands that is dry, scaly, and erythematous may occur
Suggestive of infection with T. rubrum
Other areas are frequently affected at the same time
Trichophyton rubrum infections
Moist, vesicular, eczematous types characterize infection with T. mentagrophytes
Organism seen more frequently on the feet-but can be on the hand T. rubrum & T. mentagrophytes are the two most common types
of fungus causing hand and feet dermatophytosis Occurring more frequently perhaps than true fungus is
dermatophytid of hands These commonly begin as groups of minute, clear vesicles on
palms and fingers Itching may be intense As a rule, usually both hands are involved however there are
cases in which only one hand is affected
Differential diagnosis
Allergic contact or irritant dermatitis-especially occupational
Pompholyx Atopic dermatitis Psoriasis Lamellar dyshidrosis Eczematoid or dyshidrotic lesions of unknown
cause on hands should prompt a search for clinical evidence of dermatophytosis of feet etc.
Etiology T. rubrum most frequent causative fungus Culture of organism are usually fluffy-but can be
granular or folded Backside of culture is usually deep red; sometimes no
color is produced Microconidia are found in clusters and singly on the
hyphae Macroconidia, chlamydospores, coils, and racquet
hyphae are rarely seen Less frequent causes are T. mentagrophytes and E.
floccosum
Diagnosis Demonstration of fungus by microscopic examination of
scrapings Cultures made from affected skin However, failure to find fungus does not exclude a fungal cause Tissue is scrapped off and placed on a glass slide When lesion is a vesicle, it is clipped off close to the margin by
a small, pointed scissors; when dry or scaly, material is scraped off with a scalpel or curet(obtain material from deep beneath the surface of chronic eruptions)
A drop of 20% KOH added Gentle heat applied until scales are macerated
Diagnosis Mycelium may be seen under low power, but better
observation of both hyphae and spores is obtained by use of high dry objective with reduced illumination
Lines of juncture of normal epidermal cells are hyaloid and greenish, and nay be easily mistaken for fungus structures
If you wonder whether it is really mycelium or not it is not
Rapid staining method using 100mg of chlorazol black E dye in 10 ml of dimethyl sulfoxide (DMSO) and adding it to 5% aqueous solution of KOH can be helpful
Fungus filaments under KOH mount
Diagnosis(continued) Solution is then prepared in same way as ordinary KOH
solution Viewed under bright illumination; hyphae and spores are
green against a gray background Other portion is planted on Sabouraud’s glucose agar or
Mycosel agar, and cultured at room temperature Adequate growth for id occurs in 5-14 days-depending on
type of fungus Taplin et al revised the medium-DTM for diagnosis DTM inhibits growth of bacterial and saprophytic
contaminants
DX-continued Alkaline metabolized of the dermatophytes change
color of the pH indicator in medium from yellow to red If a dermatophyte is present medium will turn red Saprophytes turn medium green C. albicans does not cause any color change, but
produces a typical yeast colony One often finds the so-called mosaic fungus It is caused by overlapping cell borders A positive KOH preparation should reveal definite
hyphal elements traversing several epidermal cells
Mosaic fungus
Prophylaxis
Hyperhidrosis is a predisposing factor Dry toes after bathing Dryness is essential if re-infection is to be avoided Use good antiseptic powder on feet after bathing-
particularly between toes Tolnaftate powder or Zeasorb medicated powders
for feet Plain talc, cornstartch, or rice powder may be
dusted into socks and shoes to keep feet dry
Treatment Clotrimazole, miconazole, sulconazole, oxiconazole, econazole,
ketaconazole, naftifine, terbinafine, butenafine-all effective Severs disease with significant maceration wet dressings or
soaks with solutions such aluminum acetate, one part to 20 parts of water are beneficial
Antiinflammatory effects of corticosteroids are markedly beneficial
Topical antibiotic ointments, such as gentamicin, effective against gram-negative organisms, are helpful additions in tx of the moist type of interdigital lesions
In ulcerative type of gram-neg toe web infections, systemic floxins are needed
Tx Keratolytic agents, such as salicylic acid, lactic acid
lotions, and Carmol are therapeutic when fungus is protected by a thick layer of overlying skin (ie soles)
Tx of fungal infection of feet and hands with griseofulvin is effective when infection is caused by pathogens such as T. mentagrophytes, T. rubrum, E. floccosum, and others
Not effective in tx of Candida albicans Griseofulvin is only effective against dermatophytes When infection is caused by T. mentagrophytes
griseofulvin does not decrease inflammatory rx
Tx-doses
Griseovulvin in ultramicronized particles taken orally in doses of 350-750 mg daily
Doage for children is 10 mg/kg/day Period of tx depends on response Repeated KOH scrapings and culture should be
neg Recommended adult doses for newer agents:
terbinafine, 250 mg/day for 2 weeks; itraconazole, 200 mg twice daily for 1 week; fluconazole, 150 mg once weekly for 4 weeks
Onychomycosis(Tinea Ungium)
Fungal infection of nail Represents up to 30% of diagnosed superficial
fungal infections Etiologic agents are species: Epidermophyton,
Microsporum, and Trichophyton fungi May also be caused by other dermatophytes,
yeasts, and nondermatophytic molds Nondermatophytic molds usually involve toenails
and are rarely seen in fingernails
Onychomycosis
Frequently clinical appearance of onychomycosis caused by one species of fungus is indistinguishable from that caused by another
However, various clues could allow one to speculate as to organism responsible
Four classic types:1.) distal subungual onychomycosis: primarily involves distal nail bed and hyponychium, with secondary involvement of underside of nail plate of fingernails and toenails
Onychomycosis caused by Trichophyton rubrum
Trichophyton mentagrophytes
2.) white superficial onychomycosis(leukonychia trichophytica):this is an invasion of the toenail plate on the surface of the nail
It is produced by T.mentagrophytes,species of Cephalosporium and Aspergillus, and Fusarium oxysporum fungus
Onychomycosis
3.) Proximal subungual onychomycosis: involves the nail plate mainly from proximal nail fold, producing a specific clinical picture
It is produced by T. rubrum & T. megninii and may be an indication of HIV infection
4.) Candidaonychomycosis involves all the nail plate; it is due to Candida albicans and is seen in pts with chronic mucocuataneous candidiasis
Onychomycosis caused by Candida albicans in mucocutaneous candidiasis
Onychomycosis Onychomycosis caused by T.
rubrum is usually a deep infection
Disease usually starts at distal corner of nail and involves the junction of nail and its bed
First a yellowish discoloration occurs, which may spread until entire nail is affected
Beneath discoloration nail plate becomes loose from nail bed
Gradually entire nail becomes brittle and separated from its bed due to piling up of keratin subungually
Nail may break off, leaving an undermined remnant that is black and yellow from dead nail and fungi that are present
Onychomycosis Caused by T. mentagrophytes is usually superficial, and
there is no paronychial inflammation Infection generally begins with scaling of nail under
overhanging cuticle and remains localized to a portion of nail
However, in time whole nail may be involved Leukonychia trichophytica is name given to this fungal
infection Small, chalky white spots appear on or in nail plate May be multiple and variously shaped or just a single spot Superficial so that they may be shaved off easily
Nail lesions caused by C. albicans there is usually paronychia Begins under lateral or proximal nail fold-small amount of pus
may be expressed Adjacent cuticle is swollen, pink, and tender on pressure Fingernails more commonly infected than toenails Encountered mostly in homemakers, canners, and others who
have hands in water a great deal Nail plate does not become friable, yellow, or white as in
trichophyton infections Remains hard and glossy unless immunocompromise is present Associated paronychia is characteristic
Distal subungal, onchomycosis occurring simulataneously with superficial white onchmycosis
Superficial white onchomycosis
Differential
Scopulariopsis brevicaulis infrequently Infection usually begins at lateral edge of nail,
burrows beneath plate, produces large quantities of cheesy debris
Hendersonula toruloidea & Scaytalidium hyalinum have been reported to cause onychomycosis, as well as moccasin-type tinea pedis
Other fugi: T. violaceum, T. schoenleinii, & T. tonsurans
Diagnosis
Microscopic and culture Immediate examination of very thin
shavings taken from diseased portions of nail
Cover slip, KOH, heat gently Culture medium-Mycosel agar or DTM
Treatment Terbinafine 250 mg/day for 6 weeks (fingernails) 12 weeks
for toenails Itraconazole, 200 mg twice daily for 1 week of each month
for 2 months (fingernails) & 3 months for toenails Fluconazole experience is less-but 150 –300 mg once
weekly for 6-12 months Griseofulvin? Therapy continued until nails are clinically
normal Low success rates 15-30% for toenails and 50-70% for
fingernails Griseofulvin does not tx nail disease caused by candida
Candidiasis
Candida proliferates in both budding and mycelial forms in outer layers of the stratum corneum where horny cells are desquamating
Organism usually is found outside living portion of the epidermis
It does not attack hair, rarely involves nail, and is incapable of breaking up the stratum corneum
It is largly an opportunisitic organism, able to behave as a pathogen mainly in impaired immune status, or in body folds
Moiture promotes its growth, in moist lip corners
Diagnosis Demonstration of the pathogenic yeast C. albicans
establishes the diagnosis Under microscope KOH prep may show spores and
peeudomycelium On gram stain yeast forms are dense, gram-positive, ovoid
bodies, 2-5 um in diameter In culture C. albicans should be differentiated from other
forms of Candida that are only rarely pathogenic Culture on Sabouraud’s glucose agar shows a growth of
creamy, grayish, moist colonies in about 4 days In time colonies form small, rootlike penetrations into agar
Mycelium and spores of Candida albicans
Candidiasis
KOH mount from infant with thrush showing pseudohyphae and yeast forms
Topical Anticandidal Agents
These include, but are not limited to: clotrimazole (Lotrimin, Mycelex), econazole (Spectazole), ketaconazole (Nizoral), miconazole (MonistatDerm Lotion, Micatin), oxiconazole (Oxistat), sulconazole (Exelderm), naftifine (Naftin), terconazole (vaginal candidiasis only), cicloprox olamine (Loprox), butenafine (Mentax), nystatin, and topical amphotericin B lotion
Terbinafine has been reported to be less active against Candidaspecies by some authors
Oral Candidiasis (Thrush) Mucous membrane of the mouth may be involved in healthy
newborn & marasmic infant Newborn infection may be acquired from contact with vaginal
tract of mother Grayish white membranous plaques are found on surface Base of plaques are moist, reddish, and macerated It is spread angles of mouth may become involved, and lesions
in intertriginous areas may occur, especially in marasmic infants
Diaper areas is especially susceptible to this Most of intertriginous areas and even exposed skin may be
involved
In adults the buccal mucosa, lips, and tongue may become involved Papillae of tongue are atrophied, surface is smooth, glazed, and bright
red Sometimes there are small erosions on edges Frequently infection extends onto angles of the mouth to form
perleche(seen in elderly, debilitated, and malnourished pts, and diabetics It is often the first manifestation of AIDS Is present in nearly 100% of all untreated pts with full-blown AIDS Observation of oral “thrush” in an adult with no known predisposing
factors warrants a search for other evidence of infection with HIV, such as lymphadenopathy, leukopenia, or HIV antibodies in serum
One predisposing factor to oral thrush is broad-spectrum antibiotics
During the 1980s there was a dramatic increase in number and severity of cases of oropharyngeal candidiasis
Reported increase of 4.7 times, from 0.34 to 1.6 cases per 1000 pediatric admission, and the number of deaths among pts tx with oropharyngeal candidiasis increased fivefold
Greatest increase was among 15-44 yr old pts at thirteenfold Rate of increase between 1985 & 1989 among pts with HIV
infection was tenfold, compared with a twofold increase among pts with malignancies or transplants
Thrush with extension to vermilion border
Tx Various tx options are available Babies with thrush may be allowed to suck on a clotrimazole
suppository inserted into the slit tip of a pacifier four times a day for 2-3 days
An adult can let tablets of clotrimazole or Mycelex troches dissolve in the mouth
In the immunocompromised goal is to reduce symptoms since continuous oral systemic therapy has led to a clinically relevant problem of drug resistance
Fluconazole, 100-200 mg/day for 5-10 days with doubling the dose if it fails, or itraconazole, 200 mg daily for 5-10 days with doubling the dose if it fails-both are available in liquid forms
Perleche
Perleche Or more aptly, angular cheilitis Maceration with transverse fissuring of oral commissures Earliest lesions are ill-defined, grayish white, thickened areas
with slight erythema of the mucous membrane at the oral commissure
When more fully developed thickening has a bluish white or mother-of-pearl color and may be contiguous with a wedge-shaped erythematous scaling dermatitis of the skin portion of commissure
Fissures, maceration, and rust formation occur Soft, pinhead-sized papules may appear Involvement is bilateral-usually
Perleche Analogous to intertrigo elsewhere, that may come from
infection by C. albicans, by coagulase-positive Staphylococcus aureus, or from manifold other causes
Similar changes may be seen in riboflavin deficiency, and iron deficiency anemia
Identical fissuring occurs in persons with malocclusion caused by ill-fitting dentures and in the aged whom atrophy of alveolar ridges has occurred
Seen in children who drool, lick their lips, or suck their thumb
Tx Depends on the cause If due to C. albicans anticandidal creams and lotions Occasionally diabetes complicates this disease, which will
persist until diabetes is brought under control It can be seen in AIDS pts with or without thrush Antibiotic topical meds are used when a bacterial; infection is
present If due to vertical shortening of lower third of the face, dental or
oral surgical intervention may help Injection of collagen into depressed sulcus at the oral
commissure may be helpful Softform implants are a more permanent tx
Candidal Vulvovaginitis C. albicans is a common inhabitant of vaginal tract May cause severe pruritus, irritation, and extreme burning Labia may be erythemtous, moist, and macerated and
cervix hyperemic, swollen, and eroded, showing small vesicles on its surface
Vaginal discharge is not usually profuse but is frequently thick and tenacious
May develop during in pregnancy, in diabetes, or secondary to therapy with a broad- spectrum antibiotic
Recurrent vulvovaginal candidiasis has been associated with long-term tamoxifen tx
Candidal Vulvovaginitis Candidal balanitis may be present in an uncircumcised
sexual partner If not recognized, repeated reinfection of a partner may
occur Diagnosis is by clinical symptoms and findings as well as
demonstration of fungus via KOH microscopic exam & culture
Tx is frustrating & disappointing due to recurrences Oral fluconazole 150 mg times 1 dose; Fluconazole,
100mg/day for 5-7 days, itraconazole, 200 mg/day for 2-3 days..other options
Tx
Topical options include miconizole (Monistat cream), nystatin vaginal suppositories or tablets (Mycostatin), or clotrimazole (Gyne-Lotrimin or Mycelex G) vaginal tablets inserted once daily for 7 days
Candidal Intertrigo Pruritic intertriginous eruptions caused by C. albicans may
arise between folds of genitals; in groins or armpits; between buttocks; under large pendulous breasts; under overhanging abdominal folds; or in umbilicus
Pinkish intertriginous moist patches are surrounded by a thin, overhanging fringe of somewhat macerated epidermis (“collarette” scale)
Some eruptions in inginal area may resemble tinea cruris, but usually there is less scaliness and a greater tendency to fissuring
Topical anticandidal preparations are usually effective Recurrence is common
Pseudo Diaper Rash In infants, C. albicans infection may start in perianal region
and spread over entire area Dermatits is enhanced by maceration produced by wet
diapers Scaly macules and vesicles with maceration in involved
areas cause burning, pruritis, and extreme discomfort Diaper friction may contribute to skin irritation and
compromised function of stratum corneum Diagnosis may be suspected by finding involvement of folds
and occurrence of many small erythematous desquamating “satellite” or “daughter” lesions scattered around edges
Diagnosis Direct KOH microscopic and culture exams Swabbing is inadequate for making smears; one must
scrape surface to remove the horny material Floor of opened pustules may be similarly scraped for
specimens Such exams are rarely needed, however Pierard-Franchimont et al showed a decrease in candidal
cultures and skin irritation after use of a miconazole nitrate-containing paste for prevention of diaper dermatitis
Pseudo diaper rash also responds well to topical antifungals that cover Candida species
Congenital Cutaneous Candidiasis
Infection of an infant during passage through birth canal
Eruption usually noted within first few hrs of delivery Erythematous macules progress to thin-walled
pustules, which rupture, dry, and desquamate within a week of so
Lesions are usually widespread, involving trunk, neck, and head, at times palms and soles, icluding nail folds
Oral cavity and diaper area are spared
Congenital Cutaneous Candidiasis
This is in contrast to the usual type of neonatal infections
Differential dx: listeriosis, syphilis, staphylococcal and herpes infections, ETN, transient neonatal pustular melanosis, miliaria rubra , drug eruption, congenital icthyosiform erythroderma (neonatal pustular disorders)
If suspected early amniotic fluid, placenta, and cord should be examined for evidence of infection
Infants with disease limited to skin have favorable outcomes
CCC Disseminated infection is suggested by (1) bw <1500g (2)
evidence of respiratory distress or labs indicating neonatal sepsis (3) tx with broad-spectrum antibiotics (4) extensive instrumentation during delivery or invasive procedures in neonatal period (5) positive systemic cultures, or (6) evidence of an altered immune response
Infants with congenital cutaneous candidiasis with any of these 6 criteria would be considered for systemic antifungal therapy
More than 16 cases of systemic disease have been reported, resulting in 2 deaths
Most did well with a combination of topical and oral antifungal therapy-uncomplicated cases topicals only are needed
Perianal Candidiasis When pruritis ani is present C.albicans should be suspected Frequently entire GI tract is involved Can be precipitated by oral antibiotic therapy Perianal dermatitis with erythema, oozing, and maceration is
present Psychogenic etiology is more common than is candidiasis Differential dx: psoriasis, seborrheic dermatitis, streptococcal
and staphylococcal infections, and contact dermatits-extramammary Paget’s disease
Fungicides, meticulous cleansing of perianal region after bowel movements, topical corticosteroids and antipruritics (Atarax)
Candidal Paronychia Chronic inflammation of nail fold produces occasional
discharge of thin pus, cushionlike thickening of paronychial tissue, slow erosion of lateral borders of nails, gradual thickening and brownish discoloration of nail plates, and development of pronounced transverse ridges
Mostly fingernails are affected, frqently only one nail Usually chronic acute forms have been reported Caused by C. albicans ,but a secondary mixed bacterial
infection can occurthose who frquently have hands in water or who handle moist objects are affected; cooks, dishwashers,bartenders,nurses,canners, etc
CP Manicuring nails sometimes is responsible for mechanical
or chemical injuries leading to infection Ingrown toenails with chronic paronychia Seen in pts with diabetes Avoid chronic moisture exposure; get diabetes under control Oral fluconazole once weekly or pulse dose itraconazole
should be effective Anticandidal lotions are probably preferable to creams and
may also be effective Topical therapy should continues for 2-3 months to prevent
recurrence
Erosia Interdigitalis Blastomycetica
Oval-shaped area of macerated white skin on web between and extending onto sides of fingers
Usually at center of lesion are one or more fissures with raw, red bases
With progression macerated skin peels off, leaving painful, raw,denuded area surrounded by a collar of overhanging white epidermis
Nearly always affects third web Moisture beneath rings macerates skin and predisposes to
infection Also seen in diabetics, those who do housework, launderers, and
others exposed to macerating effects of water and strong alkalis
EIB
Intertriginous lesions between the toes are similar Usually white, sodden epidermis that is thick and
does not peel off freely On feet fourth interspace is most often involved Areas are apt to be multiple Clinically indistinguishable from tinea pedis Dx made by culture Tx is with topical anticandidal preparations
Chronic Mucocutaneous Candidiasis
A heterogeneous group of pts whose infection with Candida is chronic but superficial
Onset before age 6 Onset in adult life may herald the occurrence of thymoma Cases are either inherited or sporadic When inherited an endocrinopathy is often found Msot cases have well-defined limited defects of cell-
immunity Oral lesions are diffuse and perleche and lip fissures are
common
CMC
Entire thickness of nail plates is involved Nails become thickened and dystrophic There is associated paronychia Hyperkeratotic, hornlike, or granulomatous lesions
are often seen Systemic fluconazole, itraconazole, or
ketaconazole is needed for prolonged and repeated and higher doses than usual
Management protocols vary and experience is limited
Systemic Candidiasis Capable of producing severe, destructive, disseminated
disease, invariably when host defenses are down High risk pts: pts with malignancies, AIDS pts,
transplant pts requiring immunosuppressive drugs, pts receiving oral cortisone, pts who have had multiple surgical operations especially cardiac, pts with indwelling catheters, and heroin addicts
Initial sign is varied: FUO,pulmonary infiltrates,GI bleeding, endocarditis, renal failure, meningitis, osteomyelitis, endophthalmitis, peritonitis, or a disseminated maculopapular eruption
SC Cutaneous findings are erythematous macules that become
papular, pustular, and hemorrhagic, and may progress to necrotic, ulcerating lesions resembling ecthyma gangrenosum
Deep abscesses may occur Trunk and extremities are usual sites of involvement Proximal muscle tenderness is a common finding Demonstration of microorganisms or a positive culture
plus clinical picture will aid diagnosis Candida colonization of endotracheal tubes in low-birth-wt
neonates predisposes to systemic disease
SC
If candida is cultured within the first week of life there is a high rate of systemic disease
There is a 50% chance of systemic disease if 1 or more cultures is positive
Mortality has declined from 80% in the 1970’s to 40% in the 1990’s because of early empiric antifungals and better prophylaxis
THE ENDTHE END
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