2. INTRODUCTION
• An ancient world wide disease caused by Sarcoptes
scabiei
• It is considered as a important health problem
worldwide especially for indegenous population and
immunocompromused individuals
3. BIOLOGY OF SCABIES
• Sarcoptes scabiei is a member of family Sarcoptidae
• It has a creamy white color with brown sclerotised legs and mouth
parts
• Adult female is larger than male
• It has 4 pairs of legs
• Unlike other arthropods it cannot fly ,they crawl as fast as 2.5cm per
minute on warm skin
6. CLINICAL FEATURES
• Incubation period is usually several weeks in a person exposed to
scabies for the first time
• Itching – most common symptom which is generalised and severe
Worsens more at night
. Due to delayed type IV hypersensitivity reaction
• Lesion- Due to the presence of mite and it’s burrows
It may be erythematous papules, papulovesicles , nodules,
erythematous rash , scratching( excoriation / eczematization )
secondary infection ( pyoderma)
7. CLASSICAL SCABIES
• Burrows are pathognomic lesion but are not easily seen
• They appear as serpiginous or S shaped greyish thread like elevation
with a vesicle at one end indicating the presence of mite
• Sites- interdigital webs, front of wrist, elbows, axilla,feet, areola and
scrotum. Palms and soles in infants
• Erythematous papules and papulo-vesicles – Excoriated found in
webspace , front of wrist, ulnar border of forearm , elbow , axilla ,
areola , umbilicus, lower abdomen , upper medial sides of thigh and
genitals . An imaginary circle formed by these sites of predilection is
called “ Circle of Hebra”
9. CLASSICAL SCABIES ( contd)
• A diffuse papular erythematous rash or urticarial lesion on the
trunk, buttock, scapular region and abdomen represents a
hypersensitivity reaction to mite
10. CLINICAL VARIANTS
• NODULAR SCABIES
• Erythematous nodules found during infestation or after treatment
• Seen in axilla or scrotum
• INFANTILE SCABIES
• Lesions are found on face, scalp, palms, soles
11. • SCABIES IN CLEAN- Fewer lesion seen at atypical and covered sites
• GENITAL SCABIES – Maybe sexually transmitted. Papule seen on
penile shaft, scrotum and inner aspects of thigh
• CRUSTED SCABIES/ NORWEGIAN SCABIES- seen in people with poor
sensory perception such as leprosy and individuals with decreased
immunity like HIV , old aged or transplant recipients
• Other risk factors – Neurologic disorders such as Parkinson’s disease ,
down’s syndrome , systemic corticosteroids , chemotherapy
• Diffuse hyperkeratotic papules and plaques develop on the palms and
soles
• Itching is mild. Xerosis of skin and nail dystrophy maybe present
13. INVESTIGATIONS
• Scraping and Microscopy
• A drop of mineral oil applied to a burrow and skin scraping are
examined under a microscope for identification of mite , eggs, egg
casings or faecal pellets
• Uncommonly performed investigations burrow ink test , needle
extraction of the mite, Histopathology
15. TREATMENT
• Treat secondary complications first
• Treat all household members
• Treat all inmates and caretakers in institution
• Treat fomites by putting in hot water, insecticides for 2-4 days
• Scabicides to be applied throughly behind ears and from neck to toes;
repeat application depending upon scabicides used
16.
17.
18. SYSTEMIC TREATMENT
• Ivermectin: 200 microgms/kg single dose; 56% cure; repeat 14 days
later, 96% cure
• Act by interrupting glutamate and aminobutyric acid induced
neurotransmission in parasite causing paralysis & death
• Lacks ovicidal action
• Better with eczematised patients
19. SUPPORTIVE TREATMENT
• Antihistaminics
• Antibiotics: systemic, local
• Emollients
• Soaps
• Steroids: Topical /Systemic (in eczematised scabies)
• Keratolytics in crusted scabies
• Future trends: Local Ivermectin, tea tree oil
20. PEDICULOSIS
Types
1.Pediculus humanus : Two varieties
a. Pediculus humanus corporis
b. Pediculus humanus capitis
2. Phthirus pubis : The gravid louse lays a few egg daily, these eggs are
called nits. They are small oval greyish white & 0.5 mm in length.
Morphology
• Head louse & body louse morphology identical (Thin & long)
• Crab louse (broad & short)
21. PEDICULOSIS CAPITIS
• It is the infestation of the scalp by pediculosa humanu capitis.
• It localizes in the scalp , favouring the occiput & temporal area.
• They are laid close to the scalp surface, at the bottom of the hair.
Clinical features :
• Itching
• Scratching causes trauma with result into oozing.
• Secondary infection usually resulting in pustulation & absscess
formation
22.
23. PEDICULOSIS CORPORIS
• It is the infestation of the body by pediculosa humanus corporis.
• The body louse inhibbits from the clothings.
• Lice bites the skin to suck blood
• Release of mild toxin
• Produces pruritic spot & strong itching
• Results in excoriations ( Hall mark of the disease)
Sites :
• Shoulder
• Trunk
• Buttocks
24. PEDICULOSIS PUBIS
• This is the infestation of the pubic & perianal hairs by phthirus pubis.
• It is usually transmitted by sexual contact.
• The adult female lays eggs & nits remain firmly adhered to the pubic
hair.
Clinical features :
• The patients complains of itching which results in scratching.
• The hairs may be matted in the thick crusts of dried pus, serum &
blood.
• The patients may also notice tiny blood spot on the underwear.
25. DIAGNOSIS
• The diagnosis is usually suspected on clinical examination &
finding the nits or the adult louse on the hair of the fibers in
the seams of the clothing, if necessary the hair of the fibers
may be observed under the low power microscope
26. TREATMENT
Pediculosis capitis :
a. 1% Gamma benzene hexacholoride
b. 25% Benzyl benzoate
c. 0.5 % malathion
Mode of applications :
• Three applications on the consecutive days followed by tying a cloth
on the scalp.
• Shampoo after 7 days.
27. 2.Pediculosis corporis :
• Patients needs a scrub bath.
• Insecticidal dusting powder should be applied to the garments lying close
to the skin.
• Laundering & ironing of the clothes.
3. Pediculosis pubis :
a. 1% Gamma benzene hexachloride
b. 25% Benxyl benzoate
c. 0.5% malathion
• Since application is usually sufficient, if necessary repeat after 3 days.
28. OTHER TREATMENT MODALITIES
• Maintain good hygiene
• Secondary bacterial infection treated with broad spectrum antibiotics
• Itching controlled by antihistaminics
