Erysipelas-Like Erythema: A Manifestation of Severe Disease Phenotype in Pediatric Patients with Familial Mediterranean Fever

OBJECTIVE: Erysipelas-like erythema is the pathognomonic skin manifestation of familial Mediterranean fever although not frequently seen in the pediatric population. This study aims to describe the differences between patients presenting with and without erysipelas-like erythema and to examine the relation of erysipelas-like erythema with subclinical inflammation in a large pediatric cohort of familial Mediterranean fever patients. MATERIALS AND METHODS: This retrospective study from a single pediatric rheumatology referral center included familial Mediterranean fever patients with a follow-up for at least 6 months in the last 5 years. Patients were grouped according to the presence of erysipelas-like erythema and subclinical inflammation. RESULTS: Among 515 patients with familial Mediterranean fever, 35 patients (6.8%) were found to present with erysipelas-like erythema, and the earliest age for erysipelas-like erythema was 2.9 years. All erysipelas-like erythema lesions were defined on lower extremities with concurrent arthritis in 21 patients (60.0%). Compared to other patients in the cohort, patients presented with erysipelas-like erythema had significantly higher frequencies of acute arthritis, subclinical inflammation, and biallelic exon 10 mutations, and they used significantly higher doses of colchicine at the latest visits (all P ≤ .002). Patients with subclinical inflammation more frequently presented with erysipelas-like erythema compared to others without subclinical inflammation (21.7% vs. 2.9%, P < .001). CONCLUSION: Erysipelas-like erythema is an uncommon but important finding that can be a sign of severe disease course and subclinical inflammation in the pediatric population with familial Mediterranean fever.