Introduction. Acne fulminans (AF) is a severe type of acne vulgaris that occurs mainly in adolescent boys. It is characterized by necrotic lesions accompanied by bone ailments, general symptoms and laboratory abnormalities.

Objective. Presentation of a patient with acne vulgaris, in whom during isotretinoin therapy a dramatic exacerbation and symptoms of acne fulminans occurred.

Case report . A 17-year-old boy with a two-year history of acne papulopustulosa was referred to the Department of Dermatology due to acne fulminans accompanied by generalized symptoms (bone ailments, elevated ESR, C-reactive protein and leukocytosis) that occurred in the course of isotretinoin treatment. A good result after isotretinoin with prednisone, and clindamycin therapy was achieved.

Conclusions . Acne fulminans is a dermatosis in which rapid application of multidrug therapy is required. In addition to topical treatment, systemic corticosteroids and antibiotics, isotretinoin is successfully used in the therapy of AF however, at the beginning of isotretinoin treatment an exacerbation of acne lesions may occur.