What is the term for lice on the head? - briefly
Head lice, scientifically known as Pediculus humanus capitis, are the insects that infest the human scalp.
What is the term for lice on the head? - in detail
The organism that infests the human scalp is commonly called head‑lice. Its scientific designation is Pediculus humanus capitis, a subspecies of the human louse (Pediculus humanus). This ectoparasite belongs to the order Phthiraptera, family Pediculidae.
Adult head‑lice measure 2–4 mm, are wingless, and have a flattened body adapted for moving through hair shafts. They feed exclusively on blood, piercing the epidermis with specialized mouthparts. A female lays 6–10 eggs (nits) per day, attaching them to the base of hair strands with a cement‑like secretion. Eggs hatch in 7–10 days, releasing nymphs that undergo three molts before reaching adulthood; the complete life cycle spans 2–3 weeks under optimal conditions.
Infestation produces itching caused by an allergic reaction to saliva, and may lead to secondary bacterial infection if the skin is broken. Diagnosis relies on visual identification of live lice or nits within 1 mm of the scalp. Microscopic examination can confirm species when necessary.
Effective management includes:
- Over‑the‑counter topical pediculicides (e.g., permethrin 1 % or pyrethrin‑based formulations) applied to the hair and scalp for the recommended duration.
- Prescription oral agents (e.g., ivermectin) for resistant cases.
- Mechanical removal of nits using a fine‑toothed comb, repeated at 2–3 day intervals for at least two weeks.
- Washing clothing, bedding, and personal items in hot water (> 60 °C) or sealing them in plastic bags for 2 weeks to eliminate dormant lice.
Prevention focuses on minimizing head‑to‑head contact, avoiding sharing combs, hats, or headphones, and conducting regular inspections in environments where close contact is common (e.g., schools). Early detection and prompt treatment reduce the risk of widespread outbreaks.