Phthirius pubis

Phthirus pubis (also known as pubic lice or crabs) is a species of insect that is a part of the Pediculidae family. This species is known for infesting human beings, specifically the pubic hair region, although they can also be found in other areas of the body where coarse hair is present.

Biology and Lifecycle

The adult Phthirus pubis is a small insect, measuring 1.1–1.8 mm in length. The female louse is slightly larger than the male. The body of the louse is broader than it is long, giving it a crab-like appearance, hence the common name "crabs".

The lifecycle of Phthirus pubis involves three stages: egg (or nit), nymph, and adult. The female louse lays eggs at the base of the pubic hair, which hatch into nymphs after about a week. The nymphs then mature into adults over the course of a week, during which time they must feed on blood. The adult lice can live for up to a month.

Transmission

Phthirus pubis is most commonly transmitted through sexual contact, although it can also be spread through sharing of clothing, towels, or bedding. The lice cannot survive for long away from the warmth and humidity of the human body, so transmission requires close contact.

Treatment

Treatment for Phthirus pubis infestation typically involves the use of over-the-counter or prescription medications that kill the lice and their eggs. In addition, all clothing, bedding, and towels used by the infested person must be washed in hot water or dry-cleaned to prevent re-infestation.

Prevention

Prevention of Phthirus pubis infestation involves avoiding sexual contact with infested individuals and not sharing clothing, towels, or bedding. Regular inspection of the pubic area can also help to detect an infestation early.

See Also

• Pediculosis pubis
• Pediculosis
• Lice