Crabs on humans refer to pubic lice (Pthirus pubis), which are tiny parasitic insects that live on coarse human hair, especially in the pubic area. They feed exclusively on human blood by biting the skin, causing itching and discomfort. Pubic lice are named "crabs" due to their crab-like appearance. They are typically transmitted through close physical or sexual contact but can also spread via infested clothing, bedding, or towels. Besides the pubic region, they can sometimes inhabit other coarse hair such as armpits, beard, eyelashes, and eyebrows. Pubic lice infestations are treatable with lotions and shampoos designed to kill these parasites. They do not transmit diseases but can cause secondary infections due to scratching.
What Are Crabs on Humans?
- Pubic lice (Pthirus pubis) are small, crab-like insects that live mainly in pubic hair.
- They feed on human blood and cause itching due to bites.
- They have a rounded body and thick legs with claws adapted to grasp coarse hair.
Transmission and Spread
- Mostly spread through sexual contact by crawling from one person’s hair to another.
- Can also spread through contact with infested clothing, bedding, or towels.
- Rare to catch from toilet seats or casual contact like handshakes.
Symptoms and Diagnosis
- Intense itching in the pubic area and other coarse hair regions.
- Visible lice or eggs (nits) attached to hair shafts.
- Possible bluish-grey spots on the skin from bites.
- Diagnosis by identifying lice or nits in hair, sometimes using a magnifying glass.
Treatment and Prevention
- Over-the-counter or prescription lice-killing creams, lotions, or shampoos.
- Cleaning and laundering clothes, bedding, and towels.
- Avoiding close physical contact with infested persons until treated.
Additional Facts
- Pubic lice infestations are common worldwide regardless of race or socioeconomic status.
- Crab lice can occasionally be found on eyelashes, eyebrows, beard, armpits, and chest.
- Infestation on eyelashes or eyebrows in children may signal sexual abuse.
This condition is medically known as pediculosis pubis or pthiriasis and while uncomfortable, it is generally not serious and manageable with proper treatment.
