How can you determine if you have lice? - briefly
Check the scalp and hair roots, especially at the neck and behind the ears, for live insects and tiny, oval eggs (nits) firmly attached to the shaft. Use a fine-tooth comb on wet hair to confirm their presence.
How can you determine if you have lice? - in detail
Detecting a head‑lice infestation requires direct observation of the scalp and hair, supplemented by symptom assessment and, when necessary, professional verification.
A systematic visual check includes:
- Separate hair into small sections using a fine‑toothed comb or a clean finger.
- Examine each strand from scalp outward, looking for live insects (tan to grayish bodies, about the size of a sesame seed) and their eggs.
- Identify nits by their oval shape, firm attachment to the hair shaft, and a chalky white or yellowish color. Nits are positioned within ¼ inch of the scalp; those farther away are usually hatched.
- Use a magnifying lens (10‑20×) to improve clarity, especially on fine hair or in low light.
Typical signs that accompany an infestation are:
- Persistent itching, especially behind ears or at the nape.
- Redness or small sores caused by scratching.
- A feeling of movement on the scalp, reported by some individuals.
- Presence of brownish or black specks that do not wash out easily.
When visual evidence is ambiguous, a lice comb—metal or plastic with teeth spaced 0.2–0.3 mm apart—can be run through damp hair. The comb collects any insects or nits, which should be inspected immediately after each pass. Repeating the combing process over several days increases detection reliability because newly hatched nits become visible after 7–10 days.
If personal examination yields inconclusive results, a healthcare professional can perform a microscopic evaluation. The specimen is placed on a slide, allowing precise identification of lice morphology and differentiation from similar artifacts such as dandruff, hair casts, or fungal spores.
Common errors to avoid:
- Mistaking dandruff or seborrheic flakes for nits; true nits are glued to the hair and do not detach easily.
- Ignoring the need to check the entire scalp; lice may cluster in less obvious regions like the crown or behind the ears.
- Relying solely on itching, which can stem from other dermatological conditions.
Accurate determination combines thorough section‑by‑section inspection, appropriate tools, symptom correlation, and, when doubt persists, expert analysis.