What is the condition called when lice are on the head? - briefly
The medical term for a head‑lice infestation is pediculosis capitis. It describes the presence of Pediculus humanus capitis on the scalp.
What is the condition called when lice are on the head? - in detail
Pediculosis capitis, commonly known as head‑lice infestation, results from the ectoparasite Pediculus humanus capitis. Female lice lay eggs (nits) on hair shafts close to the scalp; each adult can produce up to 8 eggs per day, leading to rapid population growth.
Typical manifestations include:
- Intense itching caused by an allergic reaction to lice saliva.
- Visible live lice or translucent nits attached to hair strands.
- Small red papules or excoriations from scratching.
Diagnosis relies on direct visualization. Using a fine‑toothed comb on damp hair allows detection of live insects and nits; magnification may improve accuracy. Absence of lice on the scalp but presence of nits indicates a recent or treated infestation.
Management options:
- Topical pediculicides (permethrin 1 % or pyrethrin‑based products) applied according to manufacturer instructions, repeated after 7–10 days to eliminate newly hatched lice.
- Mechanical removal with a nit comb, performed daily for 10–14 days, effective for resistant strains.
- Oral ivermectin (200 µg/kg single dose) for cases unresponsive to topical agents or where topical use is contraindicated.
Preventive measures:
- Avoid sharing combs, hats, pillows, or hair accessories.
- Wash bedding, clothing, and personal items in hot water (≥ 60 °C) or seal in plastic bags for 48 hours.
- Conduct regular head inspections in settings with close contact (schools, daycare).
Epidemiologically, head‑lice infestations affect 6–12 % of school‑aged children worldwide, with higher prevalence in crowded or low‑hygiene environments. Complications are generally limited to secondary bacterial infection from scratching, which may require topical or systemic antibiotics.
Effective control combines prompt treatment, thorough nit removal, and environmental decontamination to interrupt the life cycle and prevent recurrence.