Colchicine as rescue treatment in two pediatric patients with chronic recurrent multifocal osteomyelitis (CRMO)

Chronic Nonbacterial Osteomyelitis Associated With Familial Mediterranean Fever in Children

OBJECTIVE

Chronic nonbacterial osteomyelitis (CNO) is a noninfectious autoinflammatory bone condition that frequently occurs alongside other inflammatory diseases, such as familial Mediterranean fever (FMF). We aimed to determine the demographic, clinical, laboratory, and radiological characteristics of patients diagnosed with both FMF and CNO.

METHODS

We reviewed the medical records of pediatric patients with both CNO and FMF at 3 pediatric rheumatology centers in Turkey from December 2008 to 2022. Patients' demographics, laboratory features, imaging findings, and treatment were recorded.

RESULTS

Twelve patients with FMF and CNO were included in the study. Half of them were female. The mean ages at onset for FMF and CNO symptoms were 80 and 116 months, whereas the ages at diagnosis for FMF and CNO were 100 and 125 months, respectively. Ten patients (83.3%) had M694V mutation on at least 1 allele of the Mediterranean fever (MEFV) gene. The most common sites of osteitis were the long bones (58.3%), pelvis (50%), and clavicles (25%). Ten patients (83%) received nonsteroidal anti-inflammatory drugs; 8 (66%) received disease-modifying antirheumatic drugs; biological therapy was administered to 5 patients (41%), who did not respond to these treatments; and all patients received colchicine.

CONCLUSION

The increased frequency of FMF in patients with CNO is of interest. Because most patients with CNO and FMF carried a homozygous or combined heterozygous M694V mutation, we speculated that the M694V mutation may play a role in the development of osteitis. Further studies are needed to elucidate the link between FMF and CNO.

Chronic Recurrent Multifocal Osteomyelitis

Chronic recurrent multifocal osteomyelitis (CRMO) is an underrecognized autoinflammatory disease affecting the skeletal system. Its vague symptoms are often first attributed to growing pains, infection, or malignancy, which can lead to a delay in diagnosis for days to years. Untreated CRMO has the potential to cause debilitating skeletal deformities, arthritis, and chronic pain; hence early recognition and treatment are paramount. MRI is the gold standard for diagnosis. Treatment consists of various antiinflammatory medications and may also include bisphosphonates if vulnerable skeletal sites are involved. Even when treated, the disease may have a relapsing course lasting years.