Background/aims: The primary aim of the study was to establish the clinical efficacy and safety of a combined treatment consisting of topical 20% azelaic acid (AA) cream and the oral antibiotic minocycline in the therapy of severe inflammatory acne (nodular papulopustular acne and acne conglobata) in a comparison with oral isotretinoin therapy. The secondary aim was to establish the value of AA cream as maintenance therapy in the prevention of recurrent acne.
Methods: This open-label but randomised study involved 85 patients with nodular papulopustular acne or acne conglobata (Leeds grading scale > 4) who were treated for 6 months. In an immediately subsequent 3-month second phase, eligible patients from the initial combination group used the AA cream as maintenance therapy, while the eligible patients from the isotretinoin group served as untreated control.
Results: A 6-month course of treatment with topical 20% AA cream plus oral minocycline in 50 patients proved to be effective in nodular forms of acne (median reduction of facial comedones: 70%; of papules and pustules: 88%; of deep inflammatory acne lesions: 100%). Overall, the combined treatment was not quite as effective as treatment with oral isotretinoin (35 patients; reduction of comedones: 83%; of papules and pustules: 97%; of deep inflammatory acne lesions: 100%). In the 3-month maintenance therapy phase, about half of the patients who received AA monotherapy maintained the very good facial result achieved by the end of phase I. A similar rate was found in the patients of the isotretinoin group, who received no further active acne treatment. In the other 50% of patients, differences existed between the groups as regards the degree of deterioration: Marked deterioration occurred more frequently under AA treatment, while only slight deterioration was more frequent in the isotretinoin group. The combination was tolerated much better than isotretinoin. The incidence of local side effects observed under the combination of AA and minocycline (36.5%, mainly transient burning and itching of mild or moderate intensity) was considerably lower than that seen with isotretinoin (65.7%). The rate of local side effects of marked intensity observed under the combination, i.e. 6%, was well within the range of 5-10% previously reported for AA. The incidence of systemic side effects was lower (8%, mainly gastrointestinal symptoms) under the combined therapy than under isotretinoin (14.3%).
Conclusion: The combination of topical 20% AA cream and oral minocycline is an highly effective treatment in severe forms of acne. It is better tolerated and associated with fewer risks than oral isotretinoin - in particular, there is no risk of teratogenicity. The combination can be regarded as a valuable alternative in patients for whom isotretinoin is not indicated, who do not wish to use or can not tolerate isotretinoin therapy and particularly in female acne patients of child-bearing potential. Topical 20% AA cream can be used successfully as maintenance therapy to prolong the recurrence-free interval.