Exertional leg pain represents a severe disease phenotype in childhood familial Mediterranean fever

ABSTRACT

Objectives

Familial Mediterranean fever (FMF) is the most common monogenic autoinflammatory disease. Recurrent fever, serositis, and arthritis are common findings of the disease. In addition, musculoskeletal complaints such as exertional leg pain can be overlooked, although they are common and affect patients’ quality of life. The aim of this study was to evaluate the frequency of exertional leg pain in pediatric FMF patients and to analyze the association of this finding with other characteristics of FMF

Methods

The files of FMF patients were retrospectively evaluated. The clinical characteristics and disease severity of the patients with exertional leg pain were compared with the patients without exertional leg pain. International severity scoring system for FMF (ISSF) and Mor severity score were used for assessment.

Results

The study included 541 FMF patients (287 females), 149 (27.5%) with exertional leg pain. The median colchicine dosage was significantly higher in patients with exertional leg pain (p = 0.02), arthritis (p = 0.001) and arthralgia (p˂0.001) were encountered more frequently in the attacks of these patients. The median disease severity scores calculated by both Mor severity scale and ISSF were significantly higher in patients with exertional leg pain compared to those without (p˂0.001). In the group of patients with exertional leg pain, the M694V mutation, either in one allele or in two alleles, was found to be significantly more common (p = 0.006 and p˂0.001, respectively).

Conclusions

Exertional leg pain in pediatric FMF patients is the component of moderate-to-severe disease course, and this may be considerably associated with the presence of M694V mutation.

KEYWORDS:

• Childhood
• exertional leg pain
• familial Mediterranean fever
• M694V mutation
• severe disease

Author contributions

Fatma Aydın, Zeynep Birsin Özçakar: conceptualization, study design, writing-original draft, writing-review, and editing, read and approved the final manuscript, drafted the initial manuscript. Nilgün Çakar, Pınar Özge Avar Aydın: conceptualization, data analysis, read and approved the final manuscript. Ece Mekik Akar: data collection and analysis, read and approved the final manuscript.

Declaration of financial/other relationships

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties. Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This paper was not funded.