How can I understand if a person has lice? - briefly
Check the scalp and hair for itching, small moving insects, and tiny, oval nits firmly attached close to the roots, especially behind the ears and at the nape. Presence of live lice or nits that cannot be brushed away confirms an infestation.
How can I understand if a person has lice? - in detail
A reliable assessment begins with a visual examination of the scalp and hair. Look for the following indicators:
- Small, grayish or brownish oval objects attached to hair shafts within ¼‑inch of the scalp. These are nits, the eggs of the parasite. Viable nits are firmly cemented and do not slide easily when the hair is brushed.
- Live insects, approximately 2‑3 mm long, resembling tiny brown or gray beetles. They move quickly when the hair is disturbed.
- Red or pink spots on the scalp, neck, behind the ears, or at the hairline, caused by bites or irritation.
- Persistent itching, especially after a night of sleep, which results from an allergic reaction to lice saliva.
To differentiate nits from dandruff or hair‑shaft debris, use a fine‑tooth lice comb (0.2 mm spacing). Comb a small section of hair over a white surface; any moving particles are likely lice, while stationary, crumb‑like material is usually dandruff. A confirmed presence of live lice or viable nits confirms infestation.
If visual clues are ambiguous, perform a “wet comb” test:
- Wet the hair thoroughly; moisture immobilizes the insects.
- Apply a fine‑tooth comb, starting at the scalp and moving toward the ends.
- After each pass, wipe the comb on a white tissue or paper.
- Repeat the process across the entire head, focusing on the crown, behind the ears, and the nape of the neck.
Finding more than one live louse or several viable nits after this procedure is diagnostic. For uncertain cases, a healthcare professional can examine a sample under a microscope to verify species and stage.
Distinguish head lice from body lice by location: head lice remain on the scalp, while body lice inhabit clothing seams and move to the skin only to feed. Body‑lice infestation is often accompanied by itching on the torso and a rash on covered areas.
Key points for accurate identification:
- Examine the scalp under good lighting; a magnifying lens improves detection.
- Check personal items—hats, scarves, hair accessories, bedding, and clothing—for transferred nits.
- Conduct the inspection at least twice, 24 hours apart, because newly hatched lice may be missed initially.
A systematic visual and comb‑based approach, combined with confirmatory microscopy when needed, provides a definitive determination of infestation.