PARASITIC INFECTIONS

• Scabies• Pediculosis• Leishmaniasis• Larva migrans• Trichomoniasis• Myiasis

SCABIES

Sarcoptes scabiei ‐var.hominis

Life cycle

Life span 4‐6 weeks

40 ‐ 50 eggs in life

Adult female eggs  Six legged larva 

3‐4 days

Copulation  adult  nymph

Incubation

2 – 3 months ‐ first exposure

1day ‐1 month      ‐ re‐exposure

Pathology

Delayed hypersensitivity (mite antigen)

Mode of infestation

Close intimate contact 

(Skin to skin)

Pregnant female ‐ nymph

Clinical featuresGeneralized pruritus (night)

Skin lesions ‐ burrow

Hands

Abdomen, 

Male genitalia,

Female breast 

Burrow - characteristic lesion

Papules,Vesiculo-pustulesCrustExcoriationsSecondary pyoderma Family history

ComplicationsSecondary infectionGlomerulonephritis

Nodular scabies

Diagnosis Clinical features

Demonstration of MiteOva,Nymph Faecal pellets

TREATMENT

1. Permethrin 5% lotion/cream ‐ once2. Gamma‐benzene hexachloride 1%3. Benzyl benzoate lotion (25%)‐3 applic4. Crotamiton 1% ‐ twice daily x 2 weeks5. Ivermectin – 12mg, single oral dose

• Symptomatic      ‐ Antipruritic• Sec infection      ‐ Antibiotics• Eczematization ‐ Steroids• Treat Contacts    ‐ both 

symptomatic/ asymptomatic

NORWEGIAN SCABIES

(Crusted scabies)

Immunocompromised

Diabetic

Leukemia

Lymphomas

Mental illnesses

Specific Features

no pruritus (Slight)

• Mites     – Millions

•  Sources – for large outbreaks

• Treatment – same as scabies‐ repeat

Methotrexate

Animal scabies (mange)

Cat, dog

No burrows

Self limiting    

Treat animal

PEDICULOSIS

•Pediculus humanus

var.Capitis – P.capitis

var.Corporis – P.corporis

•Phthirus pubis – Pediculosis pubis

Life cycle

Life span 40 Days

300 eggs in life : 7 ‐10 eggs / day

Adult female eggs(nits) in 7days

Copulation  adult (1month)  nymph

Pediculosis capitis

Pediculus humanus var. capitis

‐ Close intimate contact

‐ Combs, bed,

unhygienic living

Clinical features

Scalp pruritus

Scalp pyoderma

Suboccipital

Cervical L.N.

DiagnosisMite ‐ adult, nymph, eggs

Treatment

• Permethrin 1%

• GBHC 1%

• 25% Benzyl benzoate

Pediculosis corporis(Vagabond’s disease)

Pediculus humanus var. corporisMorphologically same  – white/grey

Generalised pruritusExcoriationsSecondary infection

•Seams of clothes

Sharing clothes

DiagnosisDemonstration of mite/nymph/egg

Treatment•Disinfect clothes

•Wash – steam Iron

Pediculosis pubis(Phthirus pubis)

• Sexually transmitted disease

• Generalized pruritus

•Site - pubic hair- axillary hair- umbilicus- eyebrows- eyelashes

Diagnosis

•Lice – adult, eggs, nymph

Treatment

Same as Pediculosis capitisTreat sexual partner(s)

Larva migrans(Creeping eruption)

Cutaneous larva migrans

Ankylostoma brazalienseGnathosterma spinigerum

Strongyloides stercoralisLarva currens

DermatitisWavyStreaky 

Treatment Thiabendazole under occlusionAlbendazoleExcision

MYIASIS (Maggot infestation)Primary

FuruncularSubcutaneous migratory

SecondaryWound myiasis

DipteraHypoderma

GastrophilusOestrusDermatobisMusca

Treatment

• Turpentine oil

• Manual extraction

• Exploration

LeishmaniasisVisceral (Kala‐azar)

Cutaneous

Oriental sore (Delhi boil)

L.tropica

L. major

L.aethiopica

Vector – Sandfly (Phlebotomus)

Clinical features

I.P. – 2 months

Small nodule 

Ulcer 2‐3 months

Diagnosis  Biopsy – granulomaL‐D bodies

TreatmentAntimony compounds (Sodium stibogluconate 10mg/kg x3‐4 timesKetoconazoleItraconazole

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