Chronic nonbacterial osteomyelitis from a tertiary care referral center

Chronic nonbacterial osteomyelitis (CNO) is a little known autoinflammatory bone disorder primarily affecting children and sometimes young adults. Diagnosis is often delayed due to its varied and nonspecific initial symptoms. Very few cases are reported from India. The aim of this report is to increase the awareness of this disease among physicians, orthopedic surgeons, and rheumatologists. Four male patients were diagnosed with CNO in the past 3 years. The age at onset varied from 9 to 23 years with a median diagnostic delay of 3.5 years. All patients presented with recurrent bony pain with or without localized swelling over the affected bones. Two patients had previously undergone open surgical procedures with bone biopsies and three patients had received at least one course of antibiotics. Two patients responded well to nonsteroidal anti-inflammatory drugs alone, one patient required a short course of glucocorticoids, and another patient required methotrexate to control disease activity. This case series includes males, onset at a relatively later age in most, and a longer diagnostic delay. Thus, in addition to children and adolescents, CNO should be suspected in young adults presenting with recurrent bony pain with or without localized swelling.