How to distinguish dandruff from lice? - briefly
Dandruff appears as dry, white flakes that readily brush off the scalp, whereas lice are live insects or attached nits that can be seen moving or clinging tightly to hair shafts.
How to distinguish dandruff from lice? - in detail
Scalp flaking and head‑lice infestations often appear similar but can be separated by distinct visual and behavioral cues.
The flakes produced by a dry scalp are typically white or yellowish, irregularly shaped, and detach easily when brushed or shaken. They lack any discernible movement and do not cling to hair shafts. In contrast, lice eggs (nits) are oval, about 0.8 mm long, and adhere firmly to the base of each hair strand. Live lice are about 2–3 mm, gray‑brown, and move actively when the scalp is disturbed.
Key differences can be listed as follows:
- Size and shape: dandruff particles are larger, powdery, and irregular; nits are small, smooth, and uniformly oval.
- Attachment: flakes fall off with minimal pressure; nits remain attached unless removed with a fine‑toothed comb.
- Mobility: dandruff is inert; live lice crawl quickly and may be seen moving across the scalp.
- Location: dandruff distributes across the entire scalp and shoulders; nits concentrate near the hairline, behind ears, and at the nape.
A practical inspection involves parting the hair in several sections and examining the roots with a magnifying lens. If only loose, powdery particles are observed, the condition is likely seborrheic. If firm, oval structures are seen attached at a 45‑degree angle to the hair shaft, or live insects are visible, an infestation is present.
Treatment strategies differ markedly. Flake‑related dryness responds to medicated shampoos containing zinc pyrithione, selenium sulfide, or ketoconazole, applied according to product guidelines. Lice require mechanical removal with a nit‑comb and, when necessary, topical pediculicides such as permethrin or dimethicone, followed by repeat treatment after seven days to eliminate newly hatched insects.
Accurate identification prevents unnecessary medication and ensures that the appropriate therapeutic protocol is implemented promptly.