How to know if lice are in the hair? - briefly
Examine the scalp and hair under bright light, searching for live insects about the size of a sesame seed and for nits firmly attached to hair shafts near the scalp. Persistent itching, especially behind the ears or at the nape, further indicates infestation.
How to know if lice are in the hair? - in detail
Detecting a head‑lice infestation requires careful visual inspection and tactile examination. Adult lice are approximately 2–4 mm long, have a flattened, crab‑like body, and move quickly across the scalp. Nits (lice eggs) appear as tiny, oval, whitish or yellowish structures attached firmly to hair shafts, usually within ¼ inch of the scalp where temperature supports development.
A systematic approach improves accuracy:
- Separate hair into sections using a fine‑toothed comb, starting at the crown and moving outward.
- Examine each strand against a contrasting background; a magnifying lens can aid in distinguishing lice from dandruff.
- Identify live insects by their rapid movement; they may be spotted crawling on the scalp or clinging to hair.
- Locate nits by looking for oval shells cemented at an angle to the shaft. Viable nits are firmly glued and do not slide easily when the hair is tugged.
- Count the number of nits per section; the presence of more than a few attached nits, especially near the scalp, strongly indicates infestation.
Additional cues support diagnosis:
- Persistent itching, especially after a warm shower, suggests a reaction to lice saliva.
- Small red bumps on the scalp or neck may result from bites.
- Secondary skin irritation can develop from scratching.
Confirming an infestation may involve collecting a few specimens and comparing them to reference images or consulting a healthcare professional. Early detection allows prompt treatment and prevents spread to others.