How do lice appear on a person? - briefly
Lice are spread primarily by direct head‑to‑head contact or by sharing items like combs, hats, or bedding that contain viable eggs or nymphs. After hatching on hair shafts, they feed on blood and multiply, establishing an infestation.
How do lice appear on a person? - in detail
Lice infestations begin when nymphs or adult insects are transferred to a host’s hair or clothing. The most common species affecting humans are head lice (Pediculus humanus capitis), body lice (Pediculus humanus corporis), and pubic lice (Pthirus pubis). Each species follows the same basic process: an egg (nit) hatches into a nymph, which matures into an adult capable of laying additional eggs.
Transmission occurs primarily through:
- Direct head‑to‑head or body‑to‑body contact lasting several minutes.
- Shared personal items such as combs, hats, scarves, helmets, bedding, or towels.
- Close proximity environments (schools, shelters, camps) where contact is frequent.
Factors that increase the likelihood of infestation include:
- High population density and prolonged close contact.
- Limited access to hygiene facilities or clean clothing.
- Infested individuals who are untreated, providing a continuous source of eggs.
After attachment, lice feed on blood several times a day, causing irritation that may lead to scratching and secondary skin infection. The life cycle from egg to egg‑laying adult takes about 7–10 days under typical indoor temperatures (25–30 °C). An adult female can lay 6–10 eggs per day, depositing them close to the scalp or skin surface, where they adhere firmly to hair shafts or fibers.
Detection relies on visual identification of live insects or nits attached within 1 mm of the scalp. Early identification and prompt treatment prevent further spread and reduce the population before it reaches the reproductive stage.