Scabies Flashcards
What is Scabies defined as?
Characterised by superficial burrows, intense pruritis (especially nocturnal) and secondary infection
What are the 2 types of lesions in scabies?
Primary lesion
Secondary lesion
what is a primary lesion in scabies?
Superficial linear burrows, inflammatory papules and nodules in the Axillae and groin
what is a secondary lesion in scabies?
Small urticaria crusted papules, eczematous plaques, excoriations (wearing of the skin)
What are the common sites for scabies?
Axillae
Groin
Buttocks
Hands
Feet (especially web spaces)
Sparring of the heads and neck (except in infants)
What causes scabies?
Scabies mites remain alive for 2-3 days open clothing/sheets
Incubation period of 1 month then pruritis
Reinfection followed by hypersensitivity in 24 hours
What is the aetiology of scabies?
A mite called sarcoptes scabiei
Burrow in epidermis shortly after contact no deeper than stratum granulosum. Deposit feces in tunnels, lay eggs in burrows.
Hatched larvae migrate to skin surface and mature into adults
What are the risk factors of scabies?
Sexual promiscuity
Crowdingh
Poverty
Nosocomial (originating in a hospital)
Immunocompromised
What is the d/d for scabies?
asteatotic eczema
• dermatitis herpetiformis,
• lichen simplex chronicus (neurodermatitis)
What investigations are done for scabies?
Microscopic examination of root and content of burrow and mineral oil mount for mite, egg and feces
Skin biopsy mays sometimes show scabies mite
What is the management for scabies?
Bathe, then apply permethrin 5% cream from neck down to soles of feet and leave on for 8-14 hours, second treatment 7 days after first treatment
Use lindane (not after a shower or bath though) from neck down thinly, wash off thoroughly after 8 hours
Change underwear and linens, wash twice with detergent in hot water cycle then machine dry
Treat family and close contacts
Pruritis may persist 2-3 weeks after treatment
Mid potency topical steroids and antihistamines for symptom management
