bacterial skin infections 1
TRANSCRIPT
BACTERIAL SKIN INFECTIONS FOR PRIMARY HEALTH CARE WORKERS
Digafe Tsegaye MD ,Dermato-venerologist Hon. Assistant Professor at MMS
Introduction
The normal skin of healthy individuals is highly resistant to invasion by the wide variety of bacteria to which it is constantly exposed.
NATURAL RESISTANCE OF THE SKIN Mechanical barier Low PH (5.5) Relative dryness of the skin Sebum : antibacterial activity unsaturated long-chain fatty acids ,free fatty acids (linoleic and
linolenicacids) Sweat :?? IGM ,IGA ,IGD Normal flora
Most of the bacterial skin infections are caused principally by two organisms
These are Staphylococcus aureus Group A streptococcus
Others include coryenebacterium ,mycobacterium ,closteridia, bacillus anthracis
Common primary bacterial skin infections( PYODERMAS)
S.aureus
Impetigo
Folliculitis
Furuncle
Carbuncle
Ecthyma
Paronychia
Scarlet fever
SSSS
TSS
S.pyogenes
Erysipella
Cellulitis
Scarlet fever
Lymphangitis
Thrmbophlebitis
Necrotizing fascitis
TSS
Impetigo
Non- bullous
Bullous
Non bullous impetigo • Accounts 70 % of impetigo • Children of all age group are affected • Constitutional symptoms are abscent • Etiology : Group A Streptococcus • Presents as honey colored or yellowish colored crusted
lesions • Complicates skin conditions such as scabies ,eczema
,tinea capitis …
• RX : cloxacilline , Augumentine , cefalexine
Impetigo on the scalp
Yellowish crustes on the face
What do you see ?
What do you see ?
Impetigo complicating Eczema
What do you see ?
Impetigo complicating eczma
Bullous impetigo
• Affects infants • Caused by S.aureus ( toxin producing)
• Presents clinically as blistering lesions ( Bullae) , or Errosions
• RX : topical antibiotics +, Cefalexine , Augmentine or cloxacillne
Turbid bullous lesions
What do you see ?
FOLLICULITIS
A pyoderma that begins within the hair follicle
Superficial/Bockhart's impetigo/
Deep /Sycosisbarbae/ Rx : local +systemic
antibiotics
What do you see ?
FURUNCLE AND CARBUNCLE
A furuncle or boil is a deep-seated inflammatory nodule that develops about a hair follicle, usually from a preceding, more superficial folliculitis and often evolving into an abscess. Arise in hair-bearing sites,
particularly in regions subject to friction, occlusion.
They may complicate preexisting lesions
carbuncle
Is formed when two or more furuncles join each other
Systemic symptoms are often present such as fever ,maliase
RX : systemic antibiotics ( Cloxacilline ,cefalexin ,Augmnetine) + incission and drainage
Ecthyma
Ecthyma is usually a consequence of neglected impetigo
Untreated staphylococcal or streptococcal impetigo can extend more deeply, penetrating the epidermis, producing a shallow crusted ulcer
The lesions are slow to heal, requiring several weeks of antibiotic treatment for resolution
ecthyma
Acute paronychia
Rx : cloxacilline 500 mg po qid for 7 dyas
Incise and draine the abscess
Erysipelas
A distinct type of superficial cutaneous cellulitis with marked dermal lymphatic vessel involvement caused by group A beta-hemolytic streptococcs.
New born –GB Streptococcus
Rarely ; S.aureus
Cellulitis
Involves more of the soft tissues, extending deeper into the dermis and subcutaneous tissue.
Group A streptococci are by far the most commonetiologic agents
But occasionaly GBSC in neww born
,Gm- in immunocompromised ,.. RX: rest ,po /Iv antibiotics
Gangrenous cellulitis/Necrotizing fasciitis
Characterized by necrosis of the epidermis and deeper soft tissue structures including muscle
Characteristically rapidly developing, progressive, and accompanied by constitutional symptoms, severe pain, and tenderness, with changes in overlying skin that progress to bulla formation and frank necrosis.
Etiology : group A streptococci, histotoxic Clostridia (including C. perfringens, C.
septicum , anaeeobes DM ,operative /traumatic wounds , malnutrition MR :40 to 50 percent
Rx : surgical debridement amd pareentral antibiotics
Other infections caused by Streptococcus
Acute lymphangitis
Scarlet fever
Ecthyma
Streptococcus intertrigo Blistering distal dactylitis
Guttate psoriasis
Erythema marginatum
Purpura fulminans
Erythema multiforme like lesions
Erythrasma.
well-defined but irregular reddish brown patches, occurring in the intertriginous areas, or by fissuring and white maceration in the toe clefts.
Corynebacterium minutissimum Wood lamp examination of
erythrasma reveals a coral-red fluorescence caused by coproporphyrin III.
Pitted keratolysis
involves the stratum corneum of the web spaces and plantar surface.
Etio ; Micrococcus sedentarius
Rx : fusidic acid cream (Foban cream/erythromycin 500 mg qid for 7 days
Give treatment for hyperhidrosis
Trichomycosis axillaris and pubis
bacterial infection of the hair shaft
nodular thickenings on the hair shaft, composed of colonies of aerobic Corynebacterium.
Benzoyl peroxide wash and gel are effective as treatment and prevention against recurrence of trichomycosis.
Other less common infections
Anthrax Caused by B. anthracis
Disease is acqired from contaminated meat , skin of infected animals
Painless Swelling with central black eshar
Rx : po doxycline 100mg po bd for 3 weeks
Bacillary angomatosis
Etiology : Bartonella henselae
Exclusively present in HIV pts
RX : erythromycin 500 mg po qid for three weeks
Cutaneous TB
Is rare but not uncommon
Presents in many ways Scrofuloderma is the
most common type May be inoculated
from outside or spread from distant or adjacent organs
Mode of acquistion Hematogenous spread Lymphatic spread Direct inoculations Direct extenesions Hypersensitivity to
mycobacterium tb
Types of cutaneous TB
Tuberclosis chancre Tuberclosis verucosa
cutis Orificial tuberculosis Scrofuloderma
Lupus vulgaris
Mtestatic tuberclosis abcess
tuberclids
Lupus vulgaris
Tb lymphadenitis Lupus vulgaris
Lupus vulgaris
TB of the skin
TB osteomyelitis with skin involvement
Scrfuloderma
TB verrucosa cutis
Investigation and Treatment
Cxr ,CBC , ESR, Biopsy Category III anti-tb drugs
Tetanus Caused by closteridia tetani Anerobic gram negative bacteria Conatminate necrotic and devitalized wound May cause muscle spasm and respiratory failure Treatment High dose crystalline pencillne , diazepam Prevention : TAT