Scabies is caused by the microscopic parasite, Sarcoptes scabei. "Crabs", also known as pubic lice, are caused by Phthirus pubis. Both types of infestations are common worldwide and are thankfully fully treatable.


Scabies can be transmitted through sex as well as any other type of prolonged physical contact. Pubic lice are almost always contracted through sex. While it is possible to get either condition by sharing bedding, towels or other linens, this is less likely in the case of pubic lice as they require the warmth of a human body to survive.

What Are the Signs and Symptoms of Scabies, Lice, and Crabs?

Symptoms appear 1-3 weeks after infection.

Scabies has some clear symptoms:

  • Severe itching
  • Sores caused by the scratching
  • Rash or burrows on the skin, especially in folds of skin

Symptoms of pubic lice include:

  • Itching
  • Visible nits or live lice
  • Rash or burrows on the skin - especially in folds of skin

Obviously itching is a symptom of both conditions, without other symptoms it can't be clear which, if either, you have.


The scratching from scabies and lice can cause the onset of secondary bacterial infections. In certain situations, a more severe form of scabies can develop called crusted scabies. Other complications can include spreading the infestation throughout the household as well as to other areas of the body.

Partners and Re-infection

Sexual partners should be tested for both scabies and crabs if you have it. However, it is possible that your doctor will recommend automatic treatment for them.

How Are Scabies, Lice, and Crabs Tested & Diagnosed?

Scabies is diagnosed most often by looking at the rash. If necessary, skin scrapings can be tested for the presence of the mites or their eggs. However, it is possible to have a test come back negative and still be infested.

Pubic lice ("Crabs") are diagnosed by a visual exam. While live lice may not be seen, the presence of nits (eggs) is telling enough and no other testing is needed.

How Are Scabies, Lice, and Crabs Treated?

Scabies is treated with a prescription body lotion. Follow the directions carefully. However, generally the lotion is applied to the entire body. Leave it on for a specified time and then take a shower or bath. A second treatment may be required.

Crabs are treated in a similar fashion. After thoroughly cleaning the infested area, apply the lotion (or shampoo) and leave on for the recommended time before rinsing clean again. Nits will likely remain and should be removed with a special "nit comb". A second treatment may be required.

In both cases, any clothes or bedding used in the three days prior to treatment should be washed in hot water and dried on high.

Recovery Time

After treating for crabs or scabies, itching may continue for a few weeks, even if the treatment is successful. This is because of the allergic reaction to the bites of the parasites. Your doctor may suggest comfort measures during this time.

Sexual Activity

It is important not to have sex until your symptoms have gone away and you have completed your medication.


Re-infestations can be prevented by ensuring that all clothing and bedding is properly washed and dried. Any items that can't be machine washed should be sealed in plastic for at least three days to kill any remaining parasites.

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Quick Snapshot

Can it be cured?

Yes. Both scabies and crabs are easily treated.

Type of Infection

Parasitic. Scabies is caused by the mite, Sarcoptes scabei. And crabs are caused by pubic lice, Phthirus pubis.

How is it treated?

Medicated Lotions. Both conditions are treated with specific medicated lotions; Additionally in both cases, all clothing and bedding should be washed in hot water.

Recovery Time

Upto 2 weeks. Itching may take 2-3 weeks to go away completely.

Can I have sex?

No. Sex is not recommended until treatment of you and your partner(s) is complete.

Can I get re-infected?

Yes. If you are exposed to a person, especially sexually, re-infestation is entirely possible.

Do I Have Scabies, Lice, and Crabs

Find out whether or not you have Scabies, Lice or Crabs and what STD test is recommended using our anonymous symptom checker. Get your recommendations now!

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