Adult nits: what they are and what to do

Adults can acquire head lice through close hair-to-hair contact. The insects crawl rather than jump or fly, and infestation is not a sign of poor hygiene.

Nits look like tiny oval specks cemented to one side of a hair. Unlike dandruff or styling-product residue, they do not brush away easily. Empty egg cases may remain after successful treatment, so nits alone do not always show that live lice are still present.

Check damp, conditioned hair in good light with a fine-toothed detection comb, working systematically from the scalp to the ends. Pay particular attention behind the ears and near the nape. Itching may develop after sensitivity to louse saliva, but some adults have little or no itch.

Use a licensed head-lice product exactly as its label or a pharmacist directs. Some products require a further application because they do not kill every egg. Incorrect timing, too little product, or applying conditioner beforehand can reduce effectiveness. Wet combing is another option when performed carefully and repeated on the recommended schedule.

Examine household members and close contacts, and treat those with live lice at the same time. Avoid sharing combs, brushes, headwear, towels, or pillows until the infestation is controlled. Clean recently used hair items and bedding; extensive spraying of rooms or furniture is unnecessary.

Seek advice from a pharmacist or clinician if you cannot confirm what the specks are, treatments have been used correctly but live lice persist, or the scalp becomes increasingly painful, swollen, crusted, or weepy. These changes can follow scratching and may indicate a secondary skin infection.

Prompt assessment is also sensible before choosing a product during pregnancy or breastfeeding, when the person has a significant scalp disorder, or after a previous reaction to a lice treatment. Stop a product and obtain urgent help if it causes breathing difficulty or swelling of the face, lips, or tongue.

Ask whether live lice have been confirmed, which treatment suits your scalp and health circumstances, whether it needs another application, and how to check that it has worked. Mention every product already tried, when it was applied, and any irritation that followed.