Liendres

Liendres are the eggs of lice, typically laid by female head lice (Pediculus humanus capitis) on human hair. They are small, oval capsules about 0.8 to 1.0 mm long, with a protective shell that adheres tightly to the hair shaft using a sticky substance. Liendres are most commonly found within about 1 cm of the scalp where warmth and humidity promote development. They appear white to yellowish and remain attached even when the hair is moved; they do not move themselves.

Lifecycle and development: After laying, liendres hatch into nymphs in about 7 to 10 days depending on temperature, and the nymphs molt into adults over 9 to 12 days. Adult lice live about 30 days and feed on blood. An infestation is typically diagnosed when live lice or several attached eggs are found.

Transmission: The main route is direct head-to-head contact, common among children. Indirect transmission can occur through shared combs, hats, headphones, or bedding, though this is less common.

Diagnosis and management: Diagnosis is by careful inspection of the scalp and hair, often aided by a fine-toothed comb. Removal of nits is recommended in combination with a proven pediculicidal treatment. Treatments include topical pediculicides; follow product instructions and consider retreatment if nits remain after a week or two. Wash or seal hair accessories, clothing, and bedding; vacuum living areas. Educate household members; check close contacts.

Prevalence and public health: Liendres indicate ongoing infestation rather than poor hygiene; outbreaks are common in schools and camps. Persistent or resistant infestations should be evaluated by a clinician.