Background: Topical permethrin, applied once daily, is considered as the most effective treatment in scabies.
Methods: Eighty-nine adult immunocompetent patients with scabies were treated with 5% permethrin cream: 42 patients were treated with a single application/day (group 1); 47 patients were treated with one application/day for two consecutive days (group 2). Clinical diagnosis of scabies was confirmed by microscopical examinations. The cream was stored in refrigerator and applied cold on the entire skin surface. The cream was left on the skin for 24 hours. No other topical or systemic drugs were allowed, except for a cleanser with chlorhexidine. The treatment was repeated in all patients 7-10 days later. The follow-up was 2 months after the end of the treatment.
Results: Twenty-one patients (61.8%) in the group 1 and 34 patients (87.2%) in the group 2 were considered recovered both clinically and microscopically. Three patients (7.1%) in the group 1 and 4 patients (10.2%) in the group 2 developed a mild irritant contact dermatitis. During follow-up, three patients (7.1%) in the group 1 and two patients (4.2%) in the group 2 developed a recurrence or a re-infestation.
Conclusions: Five per cent permethrin, when applied as cold cream, on the entire skin surface, once daily for two consecutive days, is more effective than the single application in adult immunocompetent patients with scabies.