What is the name of the condition when a person has lice on their head? - briefly
The condition is called pediculosis capitis. It denotes an infestation of head lice on the scalp.
What is the name of the condition when a person has lice on their head? - in detail
Head‑lice infestation, medically termed pediculosis capitis, is an ectoparasitic condition caused by the obligate human louse Pediculus humanus capitis. The adult insect measures 2–4 mm, clings to hair shafts with clawed legs, and feeds on scalp blood several times daily.
Transmission occurs through direct head‑to‑head contact, sharing of combs, hats, or bedding, and occasionally via contaminated clothing. The life cycle comprises egg (nit) deposition on the hair shaft, hatching within 7–10 days, followed by three nymphal molts before reaching adulthood. The entire cycle spans approximately three weeks.
Typical manifestations include:
- Persistent itching, especially behind the ears and at the hairline, caused by an allergic reaction to louse saliva.
- Visible live lice or translucent nits attached close to the scalp.
- Secondary bacterial infection from excoriation.
Diagnosis relies on visual inspection using a fine‑toothed comb or magnification to locate live insects and viable eggs. Viable nits are identified by their proximity to the scalp (within 1 cm) and by the presence of an operculum.
Management strategies comprise:
- Topical pediculicides (e.g., 1 % permethrin, 0.5 % malathion) applied according to manufacturer instructions, followed by a repeat treatment after 7–10 days to eradicate newly hatched nymphs.
- Manual removal of nits with a metal comb, performed every 2–3 days for at least two weeks.
- Oral ivermectin in resistant cases, prescribed by a healthcare professional.
- Environmental measures: washing bedding and clothing at ≥ 60 °C, sealing non‑washable items in plastic bags for two weeks, vacuuming furniture.
Prevention emphasizes avoiding head contact in settings where lice are common (schools, camps), discouraging sharing of personal items, and conducting routine scalp checks in high‑risk groups.
Complications are generally limited to intense pruritus and secondary infection, which may require topical antibiotics. Prompt identification and comprehensive treatment reduce transmission and recurrence.