Acne can be associated with severe musculoskeletal and constitutional symptoms. This is a case history of a 15 year-old boy with severe acne, treated with isotretinoin, who was admitted because of high fever and weight loss of 3 weeks duration. His complaints were of severe chest and back pain, and inability to walk. His laboratory results revealed elevated erythrocyte sedimentation rate and C-reactive protein. On a pelvic radiograph bilateral sacroiliitis was noticed. Radionuclide bone scan revealed increased uptake in the right sacroiliac joint, in small vertebral bodies and sternum. A diagnosis of acne-associated musculoskeletal syndrome was made and the patient was treated with high dose steroids. His symptoms resolved and his acne improved. This case report sheds light on the relationship between acne and associated musculoskeletal syndromes. Physicians should be aware of this association in order to provide prompt and efficient treatment.