What do lice and their bites look like? - briefly
Lice are small, wingless insects about 2–4 mm long, with a flattened, elongated body and six legs that cling to hair shafts; they appear grayish‑white or brownish and move quickly when disturbed. Their bites manifest as tiny, red, itchy papules or clusters of puncture marks, often surrounded by a thin halo of inflammation.
What do lice and their bites look like? - in detail
Lice are tiny, wing‑less insects measuring 2–4 mm in length. Their bodies are flattened laterally, allowing them to move through hair shafts. Color ranges from pale gray to dark brown, often reflecting the host’s blood. Each adult possesses six legs, ending in claw‑like tarsi that grip hair strands securely. The head bears a pair of antennae and compound eyes, while the thorax bears the legs in three pairs. Females lay oval, cemented eggs (nits) that are 0.8 mm long, ivory‑white, and attached to the hair shaft within 1 mm of the scalp.
Bite marks appear as small, erythematous papules, typically 1–2 mm in diameter. They develop within hours of feeding and may become raised, forming a wheal‑like swelling. The lesions are intensely pruritic; scratching can produce secondary excoriations, crusting, or hyperpigmentation. Bites often occur in clusters, following the pattern of the louse’s movement along a hair shaft, and are most common on the neck, shoulders, and behind the ears.
Key visual cues for identification:
- Adult lice: gray‑brown, elongated, six‑legged, visible moving quickly on hair.
- Nits: firm, oval, attached close to the scalp, not easily removed.
- Bite lesions: red, itchy papules, sometimes grouped, with a central punctum.
- Absence of burrows: unlike mites, lice do not tunnel under the skin.
Distinguishing features from other dermatoses:
- Flea bites are usually scattered, larger (2–5 mm), and often appear on lower legs.
- Bed‑bug marks present as linear “breakfast‑cereal” patterns on exposed skin.
- Scabies causes burrows and intense nocturnal itching, not clustered papules on the scalp.
Recognition of these specific characteristics enables accurate assessment and timely treatment.