How do lice nits appear on a child's scalp? - briefly
Lice nits are affixed to the hair shaft near the scalp by a hardened, glue‑like secretion produced by the female insect. They appear as small, oval, white‑to‑yellowish shells that cling tightly at the base of each hair, often resembling dandruff.
How do lice nits appear on a child's scalp? - in detail
Lice eggs, commonly called nits, are minute, oval structures measuring 0.8 mm in length. Their shells are translucent to creamy‑white when freshly laid, turning brownish as the embryo matures. A sticky proteinaceous substance, often described as “cement,” secures each egg to a single hair shaft, typically within ¼ inch of the scalp where temperature supports development.
The female adult deposits eggs at a rate of two to three per day. Each egg is positioned at an angle of roughly 30 degrees to the hair, allowing the cement to grip both the hair cuticle and the shaft. After 7–10 days, the embryo consumes the interior contents and emerges as a nymph, leaving the empty shell attached to the hair.
Preferred attachment sites include the occipital region, the nape of the neck, and the area behind the ears. These locations provide warmth, protection from frequent brushing, and limited exposure to sunlight, which can desiccate the eggs.
Visual identification relies on close inspection with magnification. Key characteristics are:
- Oval shape, uniform size
- Firm attachment; attempts to slide the shell along the hair result in resistance
- Color transition from pale to dark brown as the embryo ages
- Location within a centimeter of the scalp surface
Differentiation from dandruff or hair‑line debris is essential. Dandruff flakes are loosely attached, easily displaced, and lack the consistent angle and cemented bond seen in nits.
Factors influencing the visibility of eggs include hair length, density, and grooming habits. Longer, thicker hair provides more surface area for attachment, while regular combing with a fine‑tooth nit comb can dislodge some shells, reducing apparent infestation but not eliminating viable eggs.
Effective management requires removal of all attached shells, followed by treatment of live lice with approved pediculicides. Re‑inspection after 7 days confirms the absence of newly hatched nymphs, indicating successful eradication.