Crabs
- What are crabs?
- Crabs, also known as pubic lice, are one of three types of lice (wingless insects) that
survive by attaching themselves to a
- human host and feeding on the host's blood. Crabs are not as mobile as head and body
lice. The claws of crab lice are best
- suited for attaching to coarse body hair such as pubic hair. They are dependent on human
blood, but can live up to 24 hours off
- their host.
-
- What are the signs and symptoms of crabs?
-
- Crabs feed by inserting their mouthpieces into small blood vessels in the skin and
sucking blood. The main symptom is itching
- which is caused by an allergic reaction to the bites; itching usually begins about five
days after infestation. The infected person
- then begins scratching which causes redness, irritation, and inflammation of the skin.
Crabs and their eggs are usually visible to
- the eye.
-
- How are crabs transmitted?
-
- Sexual transmission is the primary means of transmission, but non-sexual transmission
also occurs. Crabs are transmitted
- through close physical contact, such as skin-to-skin or hair-to-hair contact. Crabs are
easily transmitted nonsexually through the
- sharing of infested bedding or intimate clothing. Contracting crabs from infested toilet
seats, couches, and chairs is possible but
- extremely rare.
-
- How are crabs diagnosed?
-
- Since crabs are usually visible, no laboratory test is necessary. Diagnosis is made by a
physical exam.
-
- How are crabs treated?
-
- A number of over-the-counter topical medications are available. Both the lice and the
eggs must be killed. Additional treatment
- may be necessary if new eggs appear. All clothing and bed linen must be washed (135F).
Any remaining lice can be killed by
- drying these items in a dryer on high heat for 15-20 minutes. Vacuum mattress and bed.
- Itching may persist even after successful treatment because skin irritation or allergic
reactions. Anti-itching medications or
- hydrocortisone creams may relieve itching.