Background. Oral isotretinoin, isomer of retinoic acid, has been used in the United States for the treatment of acne for >30 years, approved by the FDA for the treatment of severe recalcitrant AV. It is recommended for the treatment of severe nodular acne, initiated at a starting dose 0.5 mg/kg/day for the first month, and then increased to 1.0 mg/kg/day thereafter as tolerated by the patient for dosing duration of 15-20 weeks. A lower relapse rate was seen for treatment with cumulative dose of ≥120 mg/kg. Side effects are hypervitaminosis A with mucocutaneous, musculoskeletal and ophthalmic systems involvement. Acne Fulminans (AF), the most severe form of acne, with an incidence of less than 1% of total acne cases, is commonly associated with fever, polyarthralgia and myopathy. Adolescent boys are the most susceptible group of patients. It is suspected that AF may be induced by low doses of isotretinoin. Treatment of AF is controversial, as there is no standard therapy. The use of corticotherapy to control AF is acknowledged, associated or not with low doses of oral isotretinoin. Case report. A 16-year-old boy from Chisinau, Republic of Moldova, presented to the Hospital of Dermatology and Communicable Diseases with skin lesions on face and back. The first symptoms appeared one year before, including comedones, inflammatory papulo-pustules on forehead. The patient was diagnosed with Acne vulgaris, papulo-pustular form. He received the treatment with antibiotic for 4 weeks with no improvement, followed by Isotretinoin (Roaccutane) 0,4 mg/kg, associated with another antibiotic during 6 weeks. During treatment initial papulo-pustules transformed into abscesses with fever and arthralgia, the reason he was hospitalized with Acne fulminans (nodular-cystic form). Status localis: extensive red nodules greater than 5 mm in diameter on the face and upper thorax, with cyanotic undertone topped with pustules, solitary scars, oily skin, closed and open comedones. The history taking revealed a hereditary background of an acne in his grandmother. The patient was treated with antibiotics and on hospital release was advised with an early introduction of prednisone at a dose 0,5-1,0 mg/kg/day for 6 weeks, slowly decreasing later on and oral isotretinoin 0,5 mg/kg/day. By time, the acne reversed to a papulo-pustular and later to a comedonal form. Conclusions. Using isotretinoin to treat AV has many benefits, despite the possibility of developing AF with cutaneous and systemic side effects. Clinicians should be aware of the risk of this complication to make the diagnosis and provide appropriate care, especially in young men, and prescribe treatment with antibiotics, steroids and suitable isotretinoin dosing.