الرحيم الرحمن الله الرحيم بسم الرحمن الله بسم

PARSITIC SKIN DISEASESPARSITIC SKIN DISEASES

BYBY

Dr Nagat SobhyDr Nagat Sobhy

Assistant prof .of dermatologyAssistant prof .of dermatology

Intended learning Intended learning objectivesobjectives1- Knowledge about parasitic skin diseases1- Knowledge about parasitic skin diseases

and method of transmissionand method of transmission..

22 - -Preventive measures and treatment ofPreventive measures and treatment of

parasitic skin diseasesparasitic skin diseases..

•Mr. Salem, 30 years Mr. Salem, 30 years old, complaining of old, complaining of itching at night itching at night affecting the skin affecting the skin around umbilicus , around umbilicus , axillae and groin of axillae and groin of 2weeks duration. 2weeks duration. Also his wife Also his wife affected by the affected by the

same conditionsame condition. .

Skin examination revealedSkin examination revealed::

Multiple papules and scratch marks Multiple papules and scratch marks around the around the umbilicus and in the umbilicus and in the axillaeaxillae

What is the probable What is the probable diagnosisdiagnosis??

ScabiesScabies

ScabiesScabiesScabies is an Scabies is an ectoparasite infestationectoparasite infestation..

It is caused by the It is caused by the mite mite Sarcoptes scabiei Sarcoptes scabiei variety variety hominis hominis an obligate human parasite an obligate human parasite that burrows tunnels downwards into the that burrows tunnels downwards into the epidermis (not deeper than the stratum epidermis (not deeper than the stratum granulosum)granulosum) . .

Mites of all developmental stages tunnel into Mites of all developmental stages tunnel into the stratum corneum and deposit faeces the stratum corneum and deposit faeces behind them; the female also lays eggs in behind them; the female also lays eggs in the tunnelsthe tunnels . .

A A photomicrographphotomicrograph of an itch of an itch mitemite( ( Sarcoptes scabiei .) .)

Photograph of the mite, Photograph of the mite, S. scabieiS. scabiei, , seen on a skin scraping from scabetic seen on a skin scraping from scabetic patientpatient

In classic scabies, there are In classic scabies, there are only about only about 11-12 11-12 female female mites per casemites per case..

HypersensitivityHypersensitivity of both of both immediate and delayed types immediate and delayed types to the mite or its products to the mite or its products has been implicated in the has been implicated in the development of development of lesions lesions other other than than burrowsburrows..

Mode of transmissionMode of transmission

--Close Close person-to-person person-to-person contactcontact..

--Sexual intercourseSexual intercourse. .

--Fomites may transmit the Fomites may transmit the infectioninfection..

Clinical pictureClinical pictureItching : Nocturnal , scratchingItching : Nocturnal , scratching …………………………………………………………………………………………………………

…………………………....

The affected sites : Delicate skin asThe affected sites : Delicate skin as …………………………………………………………………………………………………………

……………………....

Morphology of the lesion : poly morphicMorphology of the lesion : poly morphic ………………………………………………………………………………………………………………………………..

A scabies burrow under A scabies burrow under magnificationmagnification

Clinical variations of scabiesClinical variations of scabies

11--Scabies incognitoScabies incognito. .

22--Scabies in infants and young childrenScabies in infants and young children ..

33--Nodular scabiesNodular scabies . .

44--Crusted ( Norwegian ) scabiesCrusted ( Norwegian ) scabies . .

55--Animal scabiesAnimal scabies. .

CrustedCrusted (Norwegian) (Norwegian) scabiesscabiesThis type represents an abnormal host This type represents an abnormal host immune response to the sarcoptes immune response to the sarcoptes scabiei.The condition is primarily scabiei.The condition is primarily seen in the following groupsseen in the following groups::

11--The mentally retarded ( DownThe mentally retarded ( Down,,s syndrome )s syndrome )22--Patients with poor cutaneous sensation Patients with poor cutaneous sensation

( leprosy ,syringomelia ,and tabes ( leprosy ,syringomelia ,and tabes dorsalis . )dorsalis . )

33--Patients with severe systemic diseases Patients with severe systemic diseases ( leukemia ( leukemia –– diabetes ) diabetes )

44--Patients with severe immunesuppressionPatients with severe immunesuppression..

Crusted scabies in a patient Crusted scabies in a patient with no overt with no overt immunosuppressive illnessimmunosuppressive illness

Photograph of patient with Photograph of patient with hyperkeratotic rash typical hyperkeratotic rash typical of crusted (Norwegian) of crusted (Norwegian) scabiesscabies..

Crusted scabies in a patient with claw handCrusted scabies in a patient with claw hand

from past leprosyfrom past leprosy..

Bullous ScabiesBullous Scabies

--These scabies can be seen in adults These scabies can be seen in adults over 65 years of ageover 65 years of age..

--There is no linkage to an underlying There is no linkage to an underlying condition or diseasecondition or disease..

--It can mimic bullous pemphigoid It can mimic bullous pemphigoid clinically, pathologically,and clinically, pathologically,and immunopathologicallyimmunopathologically..

Diagnosis of scabiesDiagnosis of scabies

HistoryHistory

ExaminationExamination

Investigations : ScrapingInvestigations : Scraping

Complications of scabiesComplications of scabies

--Bacterial infectionsBacterial infections

- -EczematizationEczematization

--UrticariaUrticaria

--AcarophobiaAcarophobia

Treatment of scabiesTreatment of scabies

--InstructionsInstructions

--Drugs : Topical and systemicDrugs : Topical and systemic. .

Topical scabicidesTopical scabicides

11--Benzyl benzoate 10% and 25% lotionsBenzyl benzoate 10% and 25% lotions22--Pyrethrins: permethrin 5% cream, lotionPyrethrins: permethrin 5% cream, lotion

33--Malathion 0Malathion 0··5% lotion5% lotion44--Sulphur (precipitated) 2Sulphur (precipitated) 2––10% in 10% in

petrolatumpetrolatum55--Crotamiton 10% cream (Eurax )Crotamiton 10% cream (Eurax )

66--Gamma benzene hexachloride 1% cream Gamma benzene hexachloride 1% cream or emulsionor emulsion. .

Special care fore Infant------ PregnantSpecial care fore Infant------ Pregnant

Systemic drug for scabiesSystemic drug for scabies

•Ivermectin.Ivermectin. (200 μg/kg once and (200 μg/kg once and repeated after 1-2 weeks)repeated after 1-2 weeks). .

IvermectinIvermectin

11--The full benefit becomes evident whenThe full benefit becomes evident wheneradication of scabies in epidemic or eradication of scabies in epidemic or endemicendemic situations situations

22--in nursing homes and prisonsin nursing homes and prisons is needed is needed since ivermectin leads to reliable disease since ivermectin leads to reliable disease controlcontrol . .

33--Along the same lines, Along the same lines, crusted scabiescrusted scabies has has been effectively treated with ivermectin in been effectively treated with ivermectin in adults and children, sometimes in adults and children, sometimes in combination with topical permethrincombination with topical permethrin . .

Mechanism of actionMechanism of action

Ivermectin Ivermectin interrupts the interrupts the GABA-induced GABA-induced neurotransmission of many neurotransmission of many parasites.leading to paralysis parasites.leading to paralysis of the parasitesof the parasites..

Novel drugNovel drugRecently, the essential oil of the tea Recently, the essential oil of the tea tree (tree (Melaleuca alternifoliaMelaleuca alternifolia), ), containing oxygenetic terpenoids, containing oxygenetic terpenoids, was found to have rapid scabicidal was found to have rapid scabicidal and antibacterial activityand antibacterial activity..

vaccine developmentvaccine development

The multifunctional enzyme The multifunctional enzyme glutathione S-transferaseglutathione S-transferase of of S S scabiei scabiei could represent a could represent a specific target for vaccination specific target for vaccination

against human scabiesagainst human scabies . .

1313 years old female patient years old female patient complaining of itching in the complaining of itching in the scalp of 10 days duration with scalp of 10 days duration with post auricular and occipital post auricular and occipital swellingswelling

What is the probable What is the probable diagnosisdiagnosis??

PediculosisPediculosis

PediculosisPediculosis is an infestation of lice is an infestation of lice —— blood- blood-feeding ectoparasitic insects of the order feeding ectoparasitic insects of the order Phthiraptera. The condition can occur in Phthiraptera. The condition can occur in almost any species of warm-blooded animal almost any species of warm-blooded animal (i.e., mammals and birds), including (i.e., mammals and birds), including humans.Although "pediculosis" in humans humans.Although "pediculosis" in humans may properly refer to lice infestation of any may properly refer to lice infestation of any part of the body, the term is sometimes part of the body, the term is sometimes used loosely to refer to used loosely to refer to pediculosis capitispediculosis capitis, , the infestation of the human head with the the infestation of the human head with the specific head lousespecific head louse..

Pediculus humanus capitisPediculus humanus capitis (♀) Lice are small (♀) Lice are small gray brown,blood sucking insects which crawl gray brown,blood sucking insects which crawl among the hairsamong the hairs

ClassificationClassification

Pediculosis may be divided into the Pediculosis may be divided into the following typesfollowing types

11 - -Pediculosis capitis (Head lice Pediculosis capitis (Head lice infestation)infestation)

22 - -Pediculosis corporis (Pediculosis Pediculosis corporis (Pediculosis vestimenti, Vagabond's disease) vestimenti, Vagabond's disease) typhus $relapsing fevertyphus $relapsing fever

33 - -Pediculosis pubis (Crabs) STDPediculosis pubis (Crabs) STD

Pediculosis, or louse infestation, Pediculosis, or louse infestation, remains aremains a

worldwide problem. The lice that infest worldwide problem. The lice that infest human beings are almost always human beings are almost always sucking lice that live in close sucking lice that live in close association with the host and lay association with the host and lay their eggs on hair shafts or in the their eggs on hair shafts or in the seams of clothingseams of clothing

A A and and B, B, Identifying characteristics of a head Identifying characteristics of a head louselouse..

Head louse nit attached to hair Head louse nit attached to hair shaftshaft

Identifying characteristics of a Identifying characteristics of a crab lousecrab louse

TreatmentTreatment

Malathion o.5 % lotionMalathion o.5 % lotion

Anti scabetic drugsAnti scabetic drugs