What happens to an adult with lice? - briefly
An adult infested with lice suffers intense scalp itching and may develop irritation or secondary bacterial infection if the bites are scratched. Prompt removal of the insects and their eggs, combined with topical pediculicides, eliminates the infestation and prevents transmission.
What happens to an adult with lice? - in detail
An adult who becomes infested with head lice experiences several immediate and secondary effects. The insects attach to hair shafts, insert their mouthparts into the scalp, and feed on blood. This feeding causes localized irritation, leading to itching that can range from mild to intense. Repeated scratching may break the skin, creating small abrasions that increase the risk of secondary bacterial infection such as impetigo or cellulitis.
Common manifestations include:
- Pruritus: persistent scalp itchiness, often worse several days after the infestation begins.
- Visible nits: oval, white or yellowish eggs cemented to hair close to the scalp, usually within 1 cm of the skin.
- Live lice: grayish‑brown insects about 2–4 mm long, moving slowly along hair shafts.
- Redness and inflammation: localized erythema around feeding sites.
- Secondary infection signs: pus, crusting, or swelling if skin is broken.
The physiological response involves a mild allergic reaction to louse saliva. In most healthy adults, systemic symptoms such as fever or malaise are absent, but severe allergic sensitivity can produce widespread rash or hives.
Treatment proceeds in stages:
- Mechanical removal – fine‑toothed lice combs used on wet, conditioned hair to extract lice and nits; repeated sessions every 2–3 days for at least two weeks eliminate newly hatched insects.
- Topical pediculicides – FDA‑approved products containing permethrin 1 % or pyrethrin with piperonyl butoxide applied to dry hair, left for the recommended duration, then rinsed; resistance may necessitate alternative agents such as malathion 0.5 % or ivermectin lotion.
- Environmental control – washing bedding, clothing, and personal items in hot water (≥60 °C) or sealing them in plastic bags for 2 weeks; vacuuming upholstered furniture reduces residual eggs.
- Medical follow‑up – evaluation for skin infection, prescription of topical antibiotics if bacterial colonization is evident, and counseling on avoidance of reinfestation.
Prevention relies on minimizing head‑to‑head contact, avoiding sharing combs, hats, or hair accessories, and conducting regular scalp inspections in settings where lice are common (e.g., schools, gyms). Early detection limits the infestation’s duration and reduces the likelihood of complications.