How can one determine if there are lice on the head? - briefly
Inspect the scalp and hair under bright light, looking for live lice, small moving insects, or oval, attached eggs (nits) near the hair shaft; run a fine-toothed comb through wet hair to dislodge any hidden parasites. Persistent itching, especially behind the ears or at the neckline, supports the presence of an infestation.
How can one determine if there are lice on the head? - in detail
Detecting head‑lice infestation requires systematic visual examination and, when necessary, mechanical assistance. The process begins with a thorough assessment of symptoms: persistent itching, especially after washing, and a sensation of movement on the scalp. These signs prompt a direct inspection of the hair and scalp.
A bright, preferably natural, light source should illuminate the hair from multiple angles. The examiner should separate strands close to the scalp, starting at the crown and moving outward, paying special attention to the nape of the neck, behind the ears, and the hairline. Live lice appear as small, tan‑brown insects about the size of a sesame seed, with six legs visible when the insect is alive. Eggs (nits) are oval, about 0.8 mm long, and firmly attached to the hair shaft at a 45‑degree angle; they are not easily removed by a simple brush stroke.
To increase detection accuracy, use a fine‑toothed lice comb (0.2 mm spacing). The comb should be drawn through wet, conditioned hair from the scalp outward, then rinsed after each pass. Repeating the combing process several times in a single session uncovers both mobile insects and attached nits that may be missed by the naked eye. A second combing session after 7–10 days captures any newly hatched lice that emerged from eggs missed in the first examination.
If visual inspection remains inconclusive, a magnifying lens (10×) can be employed to scrutinize suspect particles. Distinguish nits from dandruff or hair product residue by attempting gentle removal: nits resist detachment without damaging the hair shaft, whereas dandruff flakes lift easily.
In clinical settings, a sample of hair can be examined under a microscope to confirm the presence of lice or eggs. The microscopic view reveals characteristic morphology: lice have a flattened, wingless body with segmented legs; nits display a translucent shell with a brown dot (the developing embryo) when viable.
Summarized detection steps:
- Observe for itching or crawling sensations.
- Inspect scalp under bright light, focusing on typical infestation zones.
- Separate hair strands and look for live insects and firmly attached oval shells.
- Perform wet combing with a fine‑toothed comb, repeating several passes.
- Re‑inspect after 7–10 days to catch newly hatched lice.
- Use magnification or microscopy for ambiguous findings.
Following this protocol provides a reliable assessment of whether a head‑lice infestation exists.