Why do lice appear on eyelashes? - briefly
Lice on the eyelash margin are usually crab lice (Pthirus pubis) transferred through close personal contact, contaminated bedding, or infested clothing. The warm, moist environment of the eyelid offers ideal conditions for the insects to attach and reproduce.
Why do lice appear on eyelashes? - in detail
Lice that colonize the eyelid margins are most often the species Phthirus pubis, commonly called crab lice. The insects are attracted to the warm, moist environment of the ocular region and to the presence of keratin in hair shafts. Transmission occurs through direct contact with an infested person, sharing of towels, pillowcases, or cosmetics, and, less frequently, by contact with contaminated clothing. Children who share bedding or engage in close physical play are particularly vulnerable.
The life cycle of these parasites consists of three stages: egg (nits), nymph, and adult. Eggs are glued to the base of each lash and hatch within 5–7 days. Nymphs mature after two molts, reaching adulthood in about two weeks. Adults live for roughly 30 days, feeding on blood from the lash follicles. Continuous feeding causes irritation, redness, and a gritty sensation that may be mistaken for a foreign body.
Clinical signs include:
- Small, grayish specks attached to the lash shaft (nits)
- Mobile, crab‑shaped insects visible at the lid margin
- Persistent itching or burning
- Redness of the conjunctiva and eyelid skin
- Secondary bacterial infection if scratching damages the tissue
Diagnosis relies on visual inspection with magnification. A slit‑lamp examination can confirm the presence of live lice and their eggs. Laboratory confirmation is rarely required but may involve microscopic identification of specimens.
Effective management consists of:
- Mechanical removal of all visible lice and nits using fine tweezers or a disposable comb.
- Application of a topical pediculicide approved for ocular use, such as 1 % permethrin cream, applied to the base of the lashes for the recommended duration.
- Re‑treatment after 7–10 days to eliminate newly hatched insects.
- Cleaning of all personal items (towels, pillowcases, makeup) in hot water or by using disposable replacements.
- Screening of close contacts and treatment of any additional cases to prevent reinfestation.
Prevention focuses on avoiding shared personal items, maintaining personal hygiene, and educating caregivers about the risk of transmission in communal settings. Early detection and prompt treatment reduce discomfort and limit spread.