Acne is a common skin disease and usually begins in early puberty, less often later. The early onset of acne vulgaris is typical, often with the rapid formation of severe torpid forms of the disease. Therefore, it requires a timely pathogenesis-based strategy for treating and preventing recurrence. Special attention is drawn to the issue of childhood acne. The most effective drugs, in particular, systemic isotretinoin (SI), for treating acne are contraindicated in children under 12 years of age, which is a great challenge in managing such patients. We present a clinical case of extremely severe acne with rapid progression in a patient aged 11 years and justify the use of systemic isotretinoin. Clinical and laboratory monitoring confirmed the high clinical effectiveness of the therapy, which resulted in clinical regression of rashes after half the course dose with no significant side effects. Given the increase in severe acne in pediatric patients, further studies are needed on the safety profile of systemic isotretinoin for its introduction into pediatric practice.