CARD15/NOD2 mutations are not related to abdominal PFAPA.

Saulsbury et al emphasize the diagnostic challenge of periodic fevers in pediatrics by describing a case of PFAPA (Periodic Fever, Aphthous stomatitis, Pharyngitis, and Cervical Adenopathy) that was eventually diagnosed as TNFa Receptor-Associated Period Fever (TRAPS). PFAPA is a syndrome and not a specific disease and\u2014as pointed out previously\u2014some symptoms, for instance aphthous stomatitis, may not be present. Moreover, other symptoms are very common, for example abdominal pain, which is present in 60% of all cases. The importance of these symptoms warrants in many children the evaluation of different diagnoses, including other periodic fevers (hyper-IgD syndrome [HIDS], TRAPS) and even Crohn\u2019s disease. We recently described three cases of HIDS in which the disease onset was characterized by a PFAPA-like symptomatology and by severe abdominal complaints