Scabies (incl. Crusted Scabies)

Condition

A highly infectious skin infestation, spread through close or sexual contact, occasionally via bedding/furniture. More common in school-aged children, nursing homes, Indigenous communities, and crowded living conditions.

History and examination

Intense itching, worse with warmth and at night; erythematous papular rash, characteristically on the hands and wrists.

Investigations

Microscopy of scrapings from a burrow confirms the diagnosis; if the mite isn’t found, a treatment trial is usually diagnostic.

Management

Adults and children >6 months: examine and treat the whole household if possible. Permethrin 5% cream applied to the whole body from the neck down (particularly hands and genitals), left overnight, washed off in the morning, repeated at 7 days. Wash sheets/clothes in hot water and sun-dry, or alternatively store for 72 hours (the expected survival limit of a mite off a host). Itch can take weeks to settle — a moderate-potency topical steroid (e.g. methylprednisolone aceponate 2–3 times daily) can help.

Crusted scabies

Occurs with a high mite load due to an inadequate immune response. Difficult to treat — seek specialist input; oral ivermectin is often needed.