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Pubic lice

Pubic lice in heterosexual men

What are pubic lice?

  • Parasitic insects (Phthirus pubis) also called ‘crab lice’ or ‘crabs’.
  • Found mainly on pubic hair in the genital area of humans.
  • They are different from head lice.
  • adult lice (crabs) or their eggs (nits) may be visible in the pubic hair – sometimes there is an itch.
  • Lice are easily treated with a lotion or cream.
  • If you have pubic lice we recommend a STI screen and HIV test.

How common are pubic lice?

  • Pubic lice infestation occurs in all races, ethnic groups and all levels of society.

How do you catch pubic lice?

  • Pubic lice are spread through sexual or intimate body contact.
  • They move by crawling from hair to hair they cannot jump or fly.
  • Occasionally pubic lice may be spread by clothing, bed linen or towels that have been used by an infested person but lice only live 24 hours off the human body
  • They cannot be caught form toilet seats.

What would I notice if I had pubic lice?

  • The incubation period is usually 5 days to several weeks
  • Pubic lice and eggs may be visible in the genital area:
    • Adult lice (crabs) may be noticed crawling amongst hair in the genital area and occasionally on other coarse body hair in the armpits, beard, eyebrows or eye lashes. They are tiny, 2mm long and tan to grey in colour but under a magnifying lens they look like crabs with 6 legs including 2 pincer like claws. They feed on human blood. Blue spots may be seen at feeding sites on the skin or even specks of blood.  Black powdery droppings may be seen in underwear.
    • Eggs (nits) are oval, pale yellow visible as dots firmly attached to the hair shaft. They are difficult to see without a magnifying lens. They take about 6-10 days to hatch and then another 2 to 3 weeks to mature into adult lice.
  • Itching in the genital area.

How do I get tested for pubic lice?

  • Examination by an experienced clinician can confirm the presence of pubic lice and eggs.

How are pubic lice treated?

  • Treat all body hair below the neck but include beards and moustaches

Treat with either:

  • MALATHION 0.5% aqueous lotion 100ml (Derbac-M): apply to dry hair. Leave on for 12 hours (overnight) before washing off.  Two 50ml bottles will be needed for a large person.


  • PERMETHRIN 1% cream rinse (Lyclear Crème Rinse). Apply to damp hair and wash out after 10mins. Two 59ml bottles will be needed for a large person.
  • Permethrin is safe during pregnancy and breast feeding.
  • Clothing or bedding that may be contaminated should be washed at high temperature (>50¢ªC).
  • All treatments from the Wolverton are free and supplied directly to you in the clinic.

What about my partner?

  • All current sexual partners should be examined and treated at the same time.
  • Previous partners in the last 2 months will also need to be treated.

What problems can untreated pubic lice lead to?

  • There are no serious long term problems but the lice won’t go away until treated.
  • Occasionally chronic infestations may go undetected.

Will pubic lice come back again after treatment?

  • Sometimes the treatment fails because:
    • either the body hair was not totally covered with the cream /lotion
    • the lotion was not applied for long enough
    • partners / contacts were not treated at the same time
    • the person was re-infected
  • If lice are still present after 7 days a new course of treatment using a different product will be needed.
  • Dead nits may be removed with a nit comb.

More information

Click here for further information on pubic lice