Seborrhoea--an indicator for poor clinical response in acne patients treated with antibiotics.

The relationship between sebum excretion rate (SER) and clinical improvement was investigated in 255 acne patients treated for 6 months with either oral erythromycin (1 g/day), minocycline (100 mg/day), oxytetracycline (1 g/day) or cotrimoxazole (400 mg/day); topical therapy was 5% benzoyl peroxide. In all but the cotrimoxazole treated group, there was a significant correlation between a high SER and reduced clinical response. This was particularly evident in those patients with an SER of greater than 2.5 micrograms/cm2/min. These patients showed only 17% improvement compared with 100% improvement in those subjects with an SER of 1.0 micrograms/cm2/min or less. The presence of obvious seborrhoea in a patient who has failed to respond to an adequate 6-month course of antimicrobial therapy, should indicate the earlier rather than later use of isotretinoin for their acne.