Protracted febrile myalgia syndrome in children with familial Mediterranean fever - systematic review and a case report.

Protracted febrile myalgia syndrome (PFMS) is a rare manifestation of familial Mediterranean fever (FMF), characterized by myalgia, fever and elevated inflammatory markers lasting several weeks. As the hallmark of FMF are short episodes of disease symptoms, the long duration of PFMS may lead to a delayed diagnosis and treatment. 1. To perform a review of literature and rheumatology textbooks focused on clinical features and treatment of PFMS in children. 2. To present our own case. All articles in Pub Med generated using the keywords "protracted febrile myalgia" and information on PFMS in seven rheumatology textbooks were collected. The systematic review was supplemented with our own case presentation. In total, 18 articles with 78 pediatric patients (including our own) were retrieved. More than half of the patients presented with PFMS as the first manifestation of FMF. All complained of myalgia, 65% of abdominal pain and 26% had a rash. Corticosteroids (CS) were effective in 77%. In all CS-refractory cases, anakinra was shown efficient. MRI was used in 5 patients and showed myositis in all of them. The scrutiny of seven rheumatology textbooks showed that PFMS presenting with myalgia was mentioned in six. Possible accompanying symptoms were described only once, the long duration of symptoms twice, the efficacy of corticosteroids three times and anakinra only once. The presented 6 year old patient manifested with fever, myalgia, abdominal pain and petechial rash lasting 6 weeks. She had undergone multiple diagnostic procedures before her parents mentioned a positive family history for FMF. The subsequent genetic testing confirmed a homozygosity for M694V pathogenic variant in the MEFV gene. The long duration of PFMS may be misleading to clinicians especially if PFMS occurs at manifestation of FMF. The fact that more than half of the reported patients experienced PFMS as the presenting symptom of FMF is one of the key findings of our study. Our case presentation demonstrates the importance of genetic testing early in suspected autoinflammatory diseases. Furthermore, MRI may be an important diagnostic tool showing myositis in PFMS.

Hospach T ，Blankenburg F ，Heinkele A ，von Kalle T ，Uziel Y ，Kallinich T ，Rücklová K ... -  《Pediatric Rheumatology》

Protracted febrile myalgia syndrome as the first manifestation of familial Mediterranean fever in children: case-based review.

Öztürk K ，Çakan M 《-》

Protracted febrile myalgia as a challenging manifestation of familial Mediterranean fever: case-based review.

Yıldırım DG ，Bakkaloglu SA ，Buyan N 《-》

Protracted febrile myalgia as a first and challenging manifestation of familial Mediterranean fever.

Familial Mediterranean fever (FMF) is an auto-inflammatory disease that causes recurrent episodes of fever, abdominal pain, chest pain, and arthritis. Although FMF is well known, protracted febrile myalgia syndrome (PFMS) is a clinical condition that is rare and difficult to diagnose than other symptoms of FMF. PFMS causes fever, myalgia, and acute phase reactant elevation that lasts 2-4 weeks if corticosteroid treatment is not given. In some cases, fever may not be seen. The purpose of this report is to share our experience with PFMS patients in our clinic. This is an observational, retrospective, single-centre study. We evaluated patients who had been diagnosed with PFMS at our paediatric rheumatology clinic. Protracted febrile myalgia syndrome was observed in 14 patients. Nine of the patients were female. The median age at the time of diagnosis of PFMS was 10 years. Only three patients had previously been diagnosed with FMF. Most of our patients were patients who had no previous complaint of FMF. PFMS attack was seen as the first clinical manifestation of FMF in 11 patients. Two patients who did not respond to steroid treatment improved with anakinra treatment. PFMS is a rare condition of FMF disease. It may be the first clinical manifestation of FMF disease. Fever may not be seen in all patients. Clinicians should be aware of this situation.

Arslanoglu Aydin E ，Baglan E ，Bagrul I ，Tuncez S ，Ozdel S ，Bulbul M ... -  《-》

Protracted Febrile Myalgia Syndrome: A Rare and Difficult Manifestation of Familial Mediterranean Fever.

Tunce E ，Ulu K ，Taşar S ，Sözeri B ... -  《-》