What are the signs that lice have appeared? - briefly
Itching on the scalp, especially after washing, and the appearance of tiny white or brown specks (nits) attached to hair shafts indicate an infestation; live lice may also be seen moving or crawling.
What are the signs that lice have appeared? - in detail
Lice infestations become apparent through several observable and physiological cues. The most immediate indicator is persistent itching on the scalp, caused by the insect’s saliva injection. Scratching often leads to small red patches, occasional swelling, and in some cases, secondary bacterial infection evident as pus‑filled lesions.
A second, unmistakable sign is the presence of nits—oval, translucent or brownish eggs firmly attached to the hair shaft. Nits are typically found within a quarter of an inch from the scalp, where the temperature supports development. Unlike dandruff, they do not flake off and remain anchored even after vigorous brushing.
Live lice can be seen moving quickly across the scalp, especially near the hairline, behind the ears, and at the nape of the neck. Adult lice measure about 2–4 mm, resembling sesame seeds in size and color. When the head is examined under bright light, lice may be spotted crawling or resting on hair strands.
Additional symptoms may include:
- A tickling sensation on the scalp, often described as a feeling of something moving.
- Increased hair loss in localized areas due to irritation.
- Swollen lymph nodes in the neck region, reflecting an immune response.
- Rare allergic reactions, such as hives or widespread rash, triggered by saliva proteins.
Detection is most reliable using a fine‑tooth comb on damp hair. The comb should be drawn from the scalp outward in sections, with each pass examined for nits or live insects. Repeating this process over several days helps confirm an active infestation, as newly hatched nymphs become visible within a week.
Overall, the combination of intense scalp itching, visible egg shells attached close to the scalp, and the sight of moving insects constitutes a comprehensive set of signs that lice have colonized the hair.