How to recognize lice on the head from a photo? - briefly
Examine the scalp image for tiny, oval, gray‑brown insects about the size of a sesame seed, and for their translucent, attached eggs (nits) cemented close to the hair shaft near the scalp. Look for itching signs, red bumps, and a “wet‑look” hair texture caused by the lice’s secretions.
How to recognize lice on the head from a photo? - in detail
Identifying head‑lice infestations in photographs requires careful observation of specific visual cues.
The adult insect measures 2–4 mm, appears as a tan‑brown oval body, and possesses six legs that end in claw‑like tarsi. In a clear image, the legs are visible as short, thin extensions near the abdomen. The head of the louse is slightly larger than the thorax, giving the insect a pear‑shaped silhouette.
Nits, the eggs, are often more reliable indicators. They are 0.8 mm long, cylindrical, and firmly attached to the hair shaft at an angle of 30–45°. The shell is translucent to white, sometimes showing a faint orange or brown hue when close to hatching. Nits are positioned within 1–2 cm of the scalp; those farther away are typically empty shells.
Key visual differences from common scalp debris:
- Dandruff consists of loose, white flakes that do not adhere to hair shafts.
- Seborrheic scales are larger, yellow‑to‑white, and lack the angled attachment seen in nits.
- Hair debris appears as detached particles, whereas nits are anchored at a consistent angle.
Optimal photographic conditions:
- Use a macro lens or smartphone attachment capable of 10×–30× magnification.
- Ensure uniform lighting; diffuse natural light reduces shadows that can obscure small details.
- Position the camera perpendicular to the scalp to capture the attachment angle of nits.
- Focus on a small section of hair (2–3 cm) near the crown, where infestations are most common.
When analyzing an image, follow a systematic approach:
- Scan for the characteristic pear‑shaped bodies with visible legs.
- Locate any cylindrical, angled structures attached to hair shafts.
- Verify the proximity of these structures to the scalp (≤2 cm).
If both adult lice and attached nits are present, the diagnosis is confirmed. Absence of these features, combined with the presence of only loose flakes, suggests a non‑infestation condition.