Pubic Pediculosis (Pubic Lice, "Crabs")
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Definition
Causative Organism
Incubation Period
Clinical Manifestations
Investigation and Diagnosis
Management
Pubic pediculosis is due to infestation with the crab
louse, Phthirus pubis.
 P.
pubis is a greyish, slate-blue or reddish-brown louse with crab-like
appendages with which it clings to hairs.
Lice which become detached from the body can live for
many hours so that recently contaminated toilet seats, towels,
underclothing or bedding can be sources of infestation.
The lice feed on blood several times a day. The female
lays eggs which are firmly attached to the hairs close to the skin. The
eggs hatch in 7 to 9 days.
The infestation is generally transferred during sexual or
close body contact or by using unwashed bedding or clothes after
their contamination by an infested person. Symptoms and signs can be
expected after a variable period, which may be several weeks.
 Intense
irritation is usually the first symptom after which comes scratching,
secondary infection and eczematous changes.
Pubic lice are rounder than head and body lice and are
visible to the naked eye, being 1-2 mm in diameter. They infest pubic hair
and occur less commonly on hairs of the chest and axillae (armpits) and
body to the knees. They
are rarely found on the eyebrows, eyelashes or in the beard.
A history of itching, skin changes, and the
demonstration of a louse or nits assists the diagnosis and makes possible
the differentiation from "neuro-dermatitis"—a common error.
See Diagnosis and management
guidelines entry for pediculosis pubis. |
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