skabb

Skabb (scabies) is a contagious skin infestation caused by the mite Sarcoptes scabiei. The mites burrow into the upper skin layers, causing intense itching and a pimple-like rash; itching is typically worse at night, due to allergic reaction to the mites, eggs, and feces.

Transmission mainly occurs through prolonged skin-to-skin contact; less commonly via contaminated clothing or bedding. Incubation from infestation to symptoms is usually 2-6 weeks for a first infection and shorter on reinfection.

Symptoms include intense nocturnal itching and burrows that appear as thin, grayish lines. Papules or vesicles may form in typical sites such as between the fingers, wrists, elbows, and genitals. In infants, the scalp and face may be involved.

Diagnosis is based on clinical assessment and history, with skin scrapings or dermoscopy used to confirm in unclear cases. Consider differential diagnoses such as dermatitis or other itchy conditions.

Treatment usually involves first-line topical scabicides such as permethrin 5% cream; oral ivermectin is an alternative in some settings. All close contacts should be treated simultaneously, even if asymptomatic. Clothing and bedding should be washed at high temperatures or sealed for several days; a second treatment is often recommended after 1–2 weeks.

Prognosis and follow-up: itching may persist for weeks after successful treatment. If symptoms worsen or new lesions appear, reassessment is advised for possible reinfestation or alternative diagnoses.

Epidemiology and prevention: scabies is found worldwide; outbreaks are common in crowded settings such as shelters, prisons, and institutions. Public health measures focus on prompt treatment of cases and contacts, and decontamination of clothing and bedding.