How can you tell if a person has lice on their head? - briefly
Examine the scalp and hair for tiny, oval eggs firmly attached within a quarter‑inch of the skin, and for live, moving lice that may cause itching. A fine‑tooth comb used on wet hair, possibly with a magnifying lens, reveals these signs quickly.
How can you tell if a person has lice on their head? - in detail
Detecting a head‑lice infestation requires a systematic visual and tactile examination. Begin with a well‑lit environment; natural daylight or a bright lamp provides the contrast needed to see tiny organisms and their eggs. Separate the hair into small sections, preferably using clips, and work from the scalp outward.
- Use a fine‑toothed lice comb (approximately 0.2 mm spacing). Comb each section from the root to the tip, then wipe the comb on a white tissue or paper. Live lice appear as brown or gray specks about the size of a sesame seed; they may move when disturbed.
- Examine the combed material for oval, white or yellowish structures attached firmly to the hair shaft. These are nits, the eggs laid by the parasite. Nits are typically found within ¼‑inch of the scalp, especially behind the ears, at the nape, and along the hairline. Their shells are resistant to removal and do not detach easily with a single pull.
- Check the scalp for signs of irritation: persistent itching, redness, or small, raised bumps (papules) that result from bites. Secondary infection may produce crusting or pus.
If a comb alone does not reveal insects, employ a magnifying glass (10× magnification) to scrutinize the hair shafts. Look for the characteristic “cigar‑shaped” nits, which differ from dandruff by their attachment angle (approximately 60° to the hair) and by remaining fixed in place when the hair is moved. Dandruff flakes are loose and fall off readily.
Confirmatory steps include:
- Wet the hair thoroughly; moisture makes lice and nits more visible.
- Run the comb over the damp hair, pausing to inspect each catch.
- Repeat the process on all sections, ensuring no area is overlooked.
- Document findings with a photograph if needed for later comparison.
Absence of live lice after two thorough combings, spaced 48 hours apart, generally indicates that an infestation is not present. However, because nits can hatch within 7‑10 days, a follow‑up examination is advisable if itching persists.
Effective detection combines adequate lighting, precise sectioning, a specialized comb, and careful inspection of both lice and their eggs. This method minimizes false positives and provides a reliable basis for treatment decisions.