Clinical efficacy and safety of a topical combination of retinaldehyde 0.1% with erythromycin 4% in acne vulgaris

The objective of this randomized, controlled, multicentre study was to asse ss the efficacy and safety of a topically applied retinaldehyde 0.1% gel in combination with a topical erythromycin 4% lotion for the treatment of acn e vulgaris, Treatment consisted of applying either retinaldehyde or its veh icle every morning and erythromycin every evening for 8 weeks. Efficacy par ameters were sequential lesion counts for papules and pustules, and a 6-poi nt semiquantitative scale for comedones and microcysts. Safety parameters w ere local tolerance and adverse events. Of 74 recruited patients, 73 were a ppraisable for efficacy and safety. In both treatment groups, papules and p ustules were reduced significantly at the end of treatment (P<0.001), and n o statistical difference was observed between the groups. Comedones and mic rocysts were significantly improved with retinaldehyde combined with erythr omycin (P=0.005), but not with erythromycin alone. However, no statistical difference between the groups could be demonstrated (test power, 50%). Loca l tolerance of the combined treatment group was very satisfactory, as only a few patients experienced local irritation. In conclusion, retinaldehyde c ombined with erythromycin appears to be a valuable topical therapy in polym orphic acne.