What is a clothing louse? - briefly
A clothing louse (Trichophthirus) is a minute, wingless parasitic insect that inhabits the seams of garments, feeding on shed human skin cells. It differs from head and body lice in habitat and rarely transmits disease.
What is a clothing louse? - in detail
The clothing louse (Pediculus humanus corporis) is a wingless, obligate ectoparasite that feeds exclusively on human blood. Adults measure 2–4 mm, are flattened laterally, and possess six clawed legs adapted for clinging to fabric fibers. The insect’s body is covered with fine hairs that increase friction against textiles, allowing it to move rapidly through seams and folds.
Life cycle proceeds entirely on the host’s clothing and consists of three stages: egg (nit), nymph, and adult.
- Eggs are cemented to fabric fibers, hatch in 6–10 days.
- Six nymphal instars follow, each requiring a blood meal before molting; development lasts 9–12 days.
- Adults live up to 30 days, feeding several times daily and producing up to 8 eggs per day.
Host interaction is limited to feeding; the louse does not burrow into skin. Bites cause localized erythema, itching, and may lead to secondary bacterial infection if scratched. Heavy infestations can produce anemia, especially in children and the elderly.
Distribution is worldwide, predominantly in regions with limited access to laundering facilities. The parasite thrives in warm, humid environments and is transmitted through shared clothing, bedding, or other textiles. Transmission does not occur via direct skin‑to‑skin contact.
Control strategies focus on removing the insect from garments and preventing re‑infestation. Effective measures include:
- Washing clothing at ≥60 °C or dry‑cleaning.
- Machine drying on high heat for at least 30 minutes.
- Isolating untreated items in sealed plastic bags for two weeks, the maximum survival time of the adult.
- Applying insecticidal powders (e.g., permethrin) to infested fabrics when laundering is unavailable.
Regular inspection of clothing, especially seams and cuffs, and prompt laundering of newly acquired garments reduce the risk of establishment. Public health programs emphasize education on proper hygiene practices and provision of adequate laundering resources to vulnerable populations.