Lice or not: how can you determine? - briefly
Examination of the scalp and hair under bright light reveals live insects, nits attached to hair shafts, or eggs within a few millimeters of the scalp. Confirmation requires careful combing with a fine‑toothed lice comb to separate and identify these particles.
Lice or not: how can you determine? - in detail
Detecting a head‑lice infestation demands a systematic visual examination combined with auxiliary tools when necessary.
The examination proceeds as follows:
- Secure bright, magnified lighting; natural daylight or a lamp with a magnifying attachment is preferred.
- Part hair in sections, beginning at the crown and moving outward.
- Use a fine‑tooth comb (approximately 0.2 mm spacing) to glide through each section, wiping the comb on a white surface after each pass.
- Observe the comb for live insects, translucent nymphs, or oval, brownish eggs (nits).
Key visual criteria distinguish viable eggs from empty shells: viable nits are firmly attached to the hair shaft within 6 mm of the scalp and display a pointed end away from the follicle. Empty shells appear translucent, unattached, and often situated farther from the scalp.
When visual inspection yields ambiguous results, supplemental methods enhance accuracy:
- A handheld magnifying glass (≥ 10× magnification) clarifies small or translucent stages.
- Commercial detection kits contain a pre‑treated comb and a dye that stains lice, improving visibility.
- Laboratory confirmation, such as microscopic slide preparation or polymerase‑chain‑reaction (PCR) testing, identifies species‑specific DNA, useful in research or persistent cases.
Interpretation of findings follows established thresholds: the presence of at least one live louse confirms infestation; detection of only unattached nits without live specimens suggests a past infestation or environmental contamination.
Following confirmation, immediate treatment includes:
- Application of a pediculicide approved by health authorities, adhering strictly to dosage and exposure time.
- Re‑combination after 7–10 days to remove newly hatched nymphs.
- Washing of bedding, clothing, and personal items at ≥ 60 °C or sealing them in plastic for two weeks to eliminate dormant eggs.
Regular monitoring for two weeks post‑treatment ensures eradication and prevents reinfestation.