What do lice on the legs look like? - briefly
Leg lice are tiny, flat, wingless insects about 2–4 mm long, with a tan‑brown body and six clawed legs for gripping hair. They look similar to head lice but inhabit the coarse hair of the thighs and lower legs.
What do lice on the legs look like? - in detail
Lice that infest the lower extremities are typically body lice (Pediculus humanus corporis) or, less commonly, crab lice (Pthirus pubis) that have migrated from their usual sites. Both species share a distinctive morphology that allows quick identification.
The insects measure 2–4 mm in length, a size comparable to a sesame seed. Their bodies are dorsoventrally flattened, facilitating movement through hair and clothing fibers. The thorax bears three pairs of short, sturdy legs, each ending in claw‑like tarsi that grip hair shafts or fabric. The legs are positioned laterally, giving the insect a crab‑like silhouette in the case of Pthirus pubis and a more elongated profile for Pediculus species.
Color varies from translucent whitish after emergence to light brown or gray after a blood meal. The exoskeleton is semi‑transparent, allowing the internal gut to appear reddish when engorged. The head is small, equipped with a pair of compound eyes and short antennae that swivel backward. Mouthparts consist of a piercing‑sucking proboscis used to draw blood from capillaries near the skin surface.
Eggs (nits) are oval, 0.8 mm long, and adhere firmly to the base of hair shafts with a cement‑like secretion. They appear as pale, oval shells that tilt away from the scalp or leg hair, often mistaken for dandruff but distinguishable by their firm attachment and elongated shape.
Key visual indicators:
- Length: 2–4 mm, comparable to a sesame seed.
- Body shape: flattened, segmented into head, thorax, abdomen.
- Legs: three pairs, ending in clawed tarsi; positioned laterally.
- Color: whitish to light brown; becomes reddish after feeding.
- Eyes and antennae: small, forward‑facing compound eyes; short, backward‑pointing antennae.
- Mouthparts: slender, adapted for blood‑sucking.
- Nits: oval, 0.8 mm, cemented to hair bases, tilted away from the scalp or leg hair.
When observed on the legs, these lice move quickly, often appearing as small, dark specks that dart across the skin or cling to clothing fibers. Their presence is confirmed by locating live insects, their characteristic egg shells, or bite marks that may develop after feeding.