Periodic Fever in Children: A Report of Three Unusual Cases

Introduction: Periodic fever syndrome (PFS) is a rare monogenic autoinflammatory disease group. The innate immune system abnormalities have a characteristic onset and spontaneous inflammation without any infectious or autoimmune trigger. It differs from autoimmune disorders (e.g., systemic lupus erythematosus (SLE)) occurring due to a defect in the adaptive immune system with auto-antibodies. Case Presentation: The clinical features of three patients presented with a periodic pattern of fever and a different constellation of symptoms were investigated. The final diagnosis of Periodic fever syndrome was reached based on standard diagnostic criteria and genetic testing. All three cases were observed to present with recurrent fever episodes at an interval of 6 - 12 weeks, 3 - 4 weeks, and one month, respectively. The first patient, presenting with a diffuse erythematous plaque-like lesion along the calf with severe calf pain and tenderness with signs of meningeal irritation, was diagnosed with a tumor necrosis factor receptor-associated periodic fever syndrome (TRAPS) like phenotype. The genetic panel was negative in this case. The second patient presenting with recurrent pharyngitis, cervical adenitis, and tonsillitis unresponsive to antibiotics was diagnosed with periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome. The last patient presenting with recurrent monoarthritis, hepatosplenomegaly, and a positive Mediterranean fever (MEFV) gene mutation was diagnosed with familial Mediterranean fever (FMF). All three patients had normal growth and development. Conclusions: Although periodic fever syndrome was an uncommon entity, it was recommended that this syndrome should be considered when a patient presented with recurring fever episodes with a characteristic constellation of symptoms.