How can lice nits be identified? - briefly
Nits are tiny, oval shells cemented directly to the hair shaft within a few millimetres of the scalp, typically white or yellow‑brown and remaining immobile even when the hair is brushed. Their firm attachment, smooth surface, and angled position differentiate them from dandruff or other debris.
How can lice nits be identified? - in detail
Lice eggs, commonly called nits, can be distinguished from other debris on the scalp by several observable traits.
The eggs are firmly attached to the hair shaft, usually within a half‑inch of the scalp where the cuticle is softer. A single nit is oval, measuring about 0.8 mm in length and 0.3 mm in width. Fresh eggs appear white or ivory, turning yellowish or gray as the embryo matures. The shell is smooth, glossy, and has a characteristic operculum—a small, curved opening at one end through which the nymph emerges. This opening is often visible as a tiny, clear “hole” when the egg is examined under magnification.
Key visual cues:
- Attachment: Cemented to the hair with a strong, seam‑like bond; removal requires a fine‑tooth comb or forceful pulling.
- Location: Predominantly near the scalp on the crown, behind ears, and at the nape of the neck; less common on loose hair sections.
- Shape and size: Oval, uniform dimensions, not elongated or irregular.
- Color progression: White → yellow → gray, correlating with developmental stage.
- Operculum: Small, rounded aperture at one pole; absent in dandruff or hair cast particles.
Effective detection steps:
- Prepare a well‑lit area or use a handheld magnifier (10–20×) to enhance detail.
- Separate hair sections with a fine‑tooth nit comb, pulling strands taut to expose the shaft.
- Inspect each strand from scalp outward, focusing on the specified zones.
- Identify attached eggs by their cemented position and operculum; note any movement when the comb is dragged—live nits may shift slightly.
- Document findings with photographs or notes for follow‑up treatment.
Differentiation from common contaminants:
- Dandruff flakes are loose, easily displaced, and lack attachment.
- Hair casts are tubular, encircle the shaft, and can be slid off without resistance.
- Sebum clumps are greasy, irregular, and not fixed at a single point.
By applying these criteria systematically, one can reliably confirm the presence of lice eggs and distinguish them from harmless scalp debris.