Efficacy and tolerability of natural synergised pyrethrins in a new thermo labile foam formulation in topical treatment of scabies: a prospective, randomised, investigator-blinded, comparative trial vs. permethrin cream.

We compared in a prospective, randomised, investigator-blinded trial, the efficacy and tolerability of a new synergised-pyrethrins thermo-labile foam (F) formulation with permethrin 5 % cream (P) in 40 patients with scabies. Clinical evolution of scabetic lesions (Clinical grading = CG) and itching intensity (IS) were assessed, using a 5-point semi-quantitative score, at baseline, at week 2 and 4. F and P were equally effective in the clinical resolution of scabetic lesions. As compared to baseline, P reduced CG and IS from 3.4 0.7 and 3.1 0.4 to 0.2 0.6 and 1.4 1, at week 2, and to 0.0 0.0 and 0.1 0.3 at week 4, respectively (P < 0.001). F reduced CG and IS from 3.3 0.5 and 3.2 0.4 to 0.05 0.2 and 0.4 0.6 (week 2) and to 0.0 0.0 and 0.0 0.0 (week 4), respectively (P < 0.0001). As compared to P group, the IS in F group, at week 2, was significantly lower (0.4 0.6 vs. 1.4 1.1) (P < 0.0013). This foam formulation was at least as effective as permethrin 5 % cream in the treatment of scabies. In comparison with permethrin the foam induced a more rapid and complete resolution of itching.