Pubic Louse (also known as Crab Louse)
Pthirus pubis
- Order & Family
- Order: Psocodea (formerly Anoplura); Family: Pthiridae
- Size
- Approximately 1.1 mm to 1.8 mm (about the size of a pinhead)
Natural Habitat
Exclusively found on human body hair, most commonly in the pubic region, but occasionally found in eyelashes, eyebrows, beard, or chest hair.
Diet & Feeding
Obligate hematophage; they feed exclusively on human blood through the skin.
Behavior Patterns
They have a crab-like appearance with specialized claws for clutching thick hair shafts. They are relatively sedentary and do not jump or fly; they spread primarily through close physical contact. The life cycle involves three stages: egg (nit), nymph, and adult, taking about 2-3 weeks to complete.
Risks & Benefits
Risks include intense itching (pruritus) due to an allergic reaction to their saliva, and small blue spots on the skin from feeding. They are not known to transmit diseases, but scratching can lead to secondary bacterial skin infections. They offer no benefits and are considered a parasitic infestation.