What should be done if a friend infected you with lice? - briefly
Use a medicated lice treatment (shampoo, lotion, or spray) and comb out all nits, then wash clothing, bedding, and personal items in hot water and dry on high heat; inform the friend so they can also treat themselves and prevent re‑infestation.
What should be done if a friend infected you with lice? - in detail
If a companion has transmitted lice, immediate action reduces discomfort and prevents further spread. First, isolate personal items such as hats, scarves, and hair accessories; place them in a sealed plastic bag for at least 48 hours, because lice cannot survive without a host for that period.
Next, treat the scalp. Apply an over‑the‑counter pediculicide containing permethrin (1 %) or pyrethrin, following the product instructions precisely: apply to dry hair, leave for the recommended duration, then rinse thoroughly. For resistant infestations, a prescription‑only preparation such as malathion (0.5 %) may be required; obtain it from a healthcare professional.
After the initial application, comb the hair with a fine‑tooth lice comb while it is still damp. Remove each nymph and egg (nits) by pulling them from the shaft; repeat the combing process every 2–3 days for two weeks to capture any hatchlings.
Wash all bedding, clothing, and towels used within the previous 48 hours in hot water (≥ 130 °F/54 °C) and dry on high heat. Items that cannot be laundered should be sealed in plastic bags for the same 48‑hour interval.
Inspect close contacts—family members, roommates, and anyone else who shared the same environment. If they show signs of infestation, repeat the treatment protocol simultaneously to avoid re‑infestation.
Finally, monitor the scalp for three weeks. Persistent itching or visible lice indicates treatment failure; consult a medical provider for alternative therapy, such as ivermectin or a second‑line pediculicide. Documentation of the incident and education on preventive measures—avoiding head‑to‑head contact and not sharing personal hair items—helps reduce future risk.