Homelessness, also name the fourth world, is a growing public health problem worldwide. Previous studies showed that up to 30% of the homeless people reported pruritus that often results in itchy lesions, which expose them to bacterial skin infections.

The investigators therefore conducted a randomized, double-blind, placebo-controlled trial to test the hypothesis that a single oral dose of ivermectin was effective in significantly reducing the prevalence of pruritus in a sheltered homeless population.

Inclusion Criteria:

• Patient HOMELESS PERSON " individual who has no regular access to a conventional residence ", appearing during the period of study at reception centers (Forbin or Madrague Ville) and being in the habit of wearing there (at least 4 times a week),
• Male genital organ and feminine,
• Of more than 18 years old,
• Presenting of the prurit, hurts of scratching or the louses
• Wishing to change his underwear,
• Having given his lit(enlightened) consent

Exclusion Criteria:

• Woman presenting a sexually transmitted infection (infection with gonococcus, with Chlamydia trachomatis, with Trichomonas vaginalis) revealing on the takings realized during the consultation of inclusion but the bacteriological results of which will be known only secondarily.
• Pregnant Woman presenting to the consultation of inclusion of métrorragies either a break of the pocket of waters or an infectious complication of the pregnancy.
• Woman removing her consent during the study.
• Lost sight Woman.
• Woman deprived of freedom, judicial or administrative;
• Woman hospitalized for quite other reason that looks for her(it);
• Woman hospitalized in a sanitary establishment or social in the other purposes that the research;
• Major Woman except state to express its consent