A double-blind, randomized trial was carried out in 44 patients with acne vulgaris to assess the effectiveness of two similar topical combination preparations, one containing hydrocortisone acetate ('Actinac') and the other without the steroid, when applied in lotion form. Patients used one or other of the two formulations twice daily for the first 4 days and then at night only for the remainder of the 3-month study period. The results showed that both treatments were effective but the full formulation-treated group showed a better response at the end of the first month's treatment in terms of percentage reduction in lesion count score, although this did not reach statistical significance. After 3 months, the average lesion count scores dropped from 82 to 11 in the full formulation and from 81 to 8 in the formulation minus hydrocortisone group.