Pediculosis

Pediculosis is an infestation with lice, small wingless insects that live on the skin and feeding on blood. There are three main forms: pediculosis capitis (head lice), pediculosis corporis (body lice), and pediculosis pubis (pubic or crab lice). Lice lay eggs, or nits, that attach firmly to hair shafts or clothing fibers, and eggs hatch into nymphs that mature into adults.

Lice spread mainly through direct close contact or by sharing personal items such as combs, hats, or clothing. Head lice live on the scalp and neck hair, laying eggs near the scalp. Body lice inhabit clothing and migrate to the skin to feed, while pubic lice inhabit coarse body hair in the genital area. The life cycle typically completes in about a month, with eggs hatching into nymphs that mature in about 1–2 weeks. Body lice are associated with poor hygiene and crowded conditions and can transmit certain diseases in some settings; head and pubic lice are not proven to transmit diseases.

Symptoms commonly include intense itching, particularly at night, and visible lice or nits on hair shafts or clothing. Diagnosis is usually made by careful inspection and combing to detect lice or nits, sometimes aided by dermoscopy. Differential diagnoses include dandruff, dermatitis, and scabies.

Treatment focuses on removing lice and nits and preventing re-infestation. Options include topical pediculicides (for example, permethrin or pyrethrin-based products) and, in some cases, alternative agents such as malathion or ivermectin. Manual removal with a fine-toothed comb and thorough laundering of clothing and bedding are advised. Close contacts may require assessment and treatment to prevent outbreaks. Prevention centers on avoiding sharing personal items and regular head checks, with particular attention in school-age children.