
Community identification
Pubic louse (or Crab louse)
Pthirus pubis
- Order & Family
- Order: Psocodea (formerly Phthiraptera), Family: Pthiridae
- Size
- 1.1 mm to 1.8 mm (about the size of a pinhead)
Natural Habitat
Found primarily in human pubic hair, but can also be found in other coarse body hair like armpits, facial hair, eyelashes, or chest hair.
Diet & Feeding
Obligate hematophage; they feed exclusively on human blood several times a day.
Behavior Patterns
They are slow-moving and cling tightly to hair shafts with specialized crab-like claws. They do not jump or fly and are usually transmitted through close physical contact or shared personal items like towels or bedding.
Risks & Benefits
Risk: Causes intense itching (pruritus) due to an allergic reaction to their saliva. Scratching can lead to secondary bacterial skin infections. They are not known to transmit systemic diseases but are considered a nuisance parasite.