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Pubic Lice

Infestation of pubic hair by a type of small wingless parasite causing irritation

  • Can affect sexually active people of any age
  • Sex with multiple partners is a risk factor
  • Gender and genetics are not significant factors

Pubic lice, often called “crabs”, are usually spread by sexual contact. The lice usually live in the pubic hair but may also sometimes occur in other hairy areas of the body, although rarely on the scalp. The adult lice are about 2 mm ( 1 / 12 in) long, feed on blood, and lay eggs called nits.

The most common symptom is itching in the affected area (most commonly the pubic area and around the anus), especially at night, although some people have no symptoms. Normal washing does not remove nits.

If you think that you or your partner has pubic lice, you should consult your doctor or go to a clinic specializing in sexually transmitted infections (STIs).

What might be done?

Your doctor will probably prescribe a preparation containing permethrin or malathion (see Preparations for skin infections and infestations). The preparation should be applied over the whole body, including the scalp, taking care to avoid getting any in the eyes. A second application is needed 7 days after the first to destroy any freshly hatched lice. To prevent the spread of lice, sexual partners should be treated if necessary. The clothing and bed linen used by an infested person should be machine-washed in hot water.

Pubic louse

This highly magnified image shows a pubic louse attached to a human hair. Lice are about 2 mm ( 1 / 12 in) in length.

From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.

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