MVK and familial Mediterranean fever: Despite a good sensitivity it has been demonstrated that a significant number of patients with monogenic periodic fevers (familial mediterranean fever (FMF), Tumor Necrosis Factor (TNF) receptor-associated periodic syndrome (TRAPS), and Mevalonate Kinase Deficiency (MKD)) also meet the diagnostic criteria for PFAPA syndrome, highlighting the poor specificity of the diagnostic criteria [4, 5].