How can you differentiate lice and nits from dandruff? - briefly
Live insects and their eggs cling firmly to hair and can be lifted with a fine‑tooth comb; nits appear as tiny, immobile, oval shells attached close to the scalp. Dandruff consists of loose, powdery skin flakes that brush away easily.
How can you differentiate lice and nits from dandruff? - in detail
Lice and their eggs (nits) differ from ordinary scalp flakes in several observable characteristics.
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Size and shape: Adult head lice measure 2–3 mm in length, have a flat, elongated body, and move quickly when disturbed. Nits are oval, about 0.8 mm long, and resemble tiny beads. Dandruff flakes are irregular, paper‑thin, and range from 0.2 to 2 mm in diameter.
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Attachment: Nits are cemented to hair shafts about ¼ inch (6 mm) from the scalp, forming a firm, immovable line. Dandruff rests loosely on the scalp and falls off with gentle brushing or washing.
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Color and texture: Live lice appear gray‑brown, with a slightly translucent exoskeleton. Nits are initially white or yellow, turning brown as embryos develop. Dandruff is usually white or light gray, dry and powdery.
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Mobility: When a comb or finger nudges a louse, it crawls away rapidly. Nits remain stationary. Dandruff does not move.
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Response to moisture: Wetting the scalp and hair causes dandruff to clump and become easier to brush away, while nits stay attached and lice may become more visible against the damp background.
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Location on hair: Nits are found close to the scalp, often in the posterior hairline, behind ears, and near the crown. Dandruff can appear anywhere on the scalp but does not preferentially cluster near the root.
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Associated symptoms: Persistent itching, especially after a night’s sleep, often signals lice activity. Dandruff may cause mild irritation but rarely produces intense, localized itching.
Practical identification steps
- Part hair into small sections, starting at the nape and moving upward.
- Examine each section under good lighting, using a magnifying lens if available.
- Look for live insects moving on the scalp or nits firmly attached to the shaft near the scalp.
- Gently pull a strand of hair; nits will not detach, while dandruff will slide off.
- If uncertain, wet the hair, comb with a fine‑tooth lice comb, and re‑inspect.
When live lice or attached eggs are confirmed, treatment should target both stages: a pediculicide for adults and a nit‑removal comb for eggs. Dandruff, in contrast, responds to anti‑flaking shampoos containing zinc pyrithione, selenium sulfide, or ketoconazole.
By focusing on size, attachment, mobility, location, and response to moisture, one can reliably separate parasitic infestations from simple scalp desquamation.