A double-blind, controlled multi-centre trial with 238 patients was employed to study the relative merits of three treatment schedules in acne vulgaris. Schedule A consisted of oral oxytetracycline and topical vitamin A acid cream (0.05%), schedule B of oral oxytetracycline alone, and schedule C of vitamin A acid alone. Large and statistically significant reductions occurred in the number of come dones, papules and pustules during 8 weeks of therapy, which could be attributed neitherto placebo effects nor to natural history of the disease.
No takes yet. Share an insight, caveat, or question.
Christiansen et al. (2009) studied this question.