How do lice appear in general? - briefly
Lice infestations start when adult females deposit eggs (nits) on hair close to the scalp; the eggs hatch within 7‑10 days, releasing nymphs that feed on blood and mature in about another week. Transmission occurs through direct head‑to‑head contact or sharing personal items such as combs, hats, or pillows.
How do lice appear in general? - in detail
Lice infestations begin when adult females deposit eggs (nits) on hair shafts close to the scalp. Each egg hatches in 7–10 days, releasing a nymph that matures after three molts over 9–12 days. The entire cycle from egg to reproducing adult takes about three weeks under optimal temperature (30 °C) and humidity (70 %).
Infestation sources include direct head‑to‑head contact, shared personal items such as combs, hats, or pillows, and, for body lice, contaminated clothing. Crowded living conditions and limited access to laundering facilities increase the likelihood of transmission.
Key factors influencing appearance of lice:
- Host proximity: Frequent physical contact among children in schools or daycare centers.
- Clothing hygiene: Inadequate washing of garments and bedding creates a reservoir for body lice.
- Environmental conditions: Warm, humid climates accelerate egg development and adult activity.
- Personal grooming: Infrequent shampooing or hair trimming provides more attachment sites for eggs.
- Immune response: Minimal skin irritation may allow unnoticed growth of the population before detection.
Species differences affect where lice are found:
- Head lice (Pediculus humanus capitis): Attach to scalp hair; nits are firmly glued to strands.
- Body lice (Pediculus humanus corporis): Live on clothing seams; lay eggs on fabric, moving to the skin to feed.
- Pubic lice (Pthirus pubis): Prefer coarse hair of the genital region; spread mainly through sexual contact.
Detection relies on visual identification of live insects or nits within 1 mm of the scalp. Early recognition permits prompt treatment, preventing the population from reaching the reproductive peak that characterizes a full‑blown infestation.