How to determine the presence of pubic lice? - briefly
Examine the pubic area for small, crab‑shaped insects and their oval, white‑to‑brown eggs attached to hair shafts; persistent itching and a reddish rash often accompany infestation. Use a magnifying lens or dermatoscope to verify the presence of lice by observing their distinctive movement and body shape.
How to determine the presence of pubic lice? - in detail
Detecting pubic lice requires a systematic visual and tactile assessment of the affected regions. The insects are minute, crab‑shaped parasites measuring 1–2 mm, typically grayish‑brown, and move rapidly when disturbed. Their eggs, or nits, appear as tiny, white, oval structures firmly attached to the hair shaft within a millimetre of the skin.
Begin the examination in a well‑lit environment, preferably with a magnifying device or a handheld dermatoscope. Use a handheld mirror to view the pubic area, and consider a partner’s assistance for hard‑to‑reach sites. Systematically inspect the following locations, as infestation can extend beyond the genital region: pubic hair, perianal hair, abdominal hair, armpit hair, chest hair, facial hair, and even coarse body hair on the legs or buttocks.
Key visual indicators include:
- Live adult parasites: oval body with six legs, the two front pairs enlarged and claw‑like.
- Nits: translucent, oval, firmly glued to the base of each hair; they do not slide when the hair is tugged.
- Small, bluish‑gray macules (maculae ceruleae) caused by louse saliva; these may be faint but are distinctive.
- Red papules or tiny wheals resulting from bites, often accompanied by intense itching.
If visual confirmation is uncertain, employ a fine‑toothed lice comb. Comb the hair in short sections, wiping the comb on white tissue after each pass to collect any attached organisms. Examine the collected material under a light microscope at 10–40× magnification; adult lice and nits are readily identifiable by their morphology.
When self‑assessment yields ambiguous results, seek professional evaluation. A clinician can perform a dermatoscopic inspection, obtain a skin scraping for microscopic analysis, and differentiate the infestation from other pruritic conditions such as scabies, dermatitis, or fungal infections. Laboratory confirmation provides definitive diagnosis and guides appropriate treatment.