Patient 3 (III-1 in Fig. b) is a 12-year-old girl who is the first child of non-consanguineous Japanese parents. At 2 months of age, she presented with 38–39 °C fever accompanied by abdominal pain, diarrhea, ankle arthralgia, oral ulcers, pharyngalgia, and an enlarged tonsil. Febrile attacks were recurrent every 1–2 weeks and resolved within 4 days. She presented with perianal ulcers (at 4 years old), bloody stool, and weight loss (at 5 years old), but colonoscopy did not identify any abnormality. At 9 years of age, she was prescribed with naproxen and methotrexate (MTX) because of left ankle arthritis, but MTX was stopped because of abdominal pain. She was treated with colchicine and mesalazine for abdominal pain, but they were not effective. At 10 years of age, she was suspected of having a periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome and was treated with cimetidine, which contributed to a reduction in the number of febrile attacks. Gastrointestinal and capsule endoscopy revealed multiple ulcers throughout the intestinal tract (Fig. ), and mesalazine was re-administered. Histopathology of ulcer biopsies showed infiltration of lymphocytes and plasma cells. There was no evidence of granuloma, cryptitis, or crypt abscess, and the findings were thought to indicate nonspecific chronic inflammation. At 11 years of age, bilateral non-granulomatous acute anterior uveitis was revealed by ophthalmologic examination and diagnosed as BD. She did not show any neurodevelopmental delay. Currently, she experiences genital ulcers and has been treated with colchicine (400 mg/day), cimetidine (1.0 mg/day), and corticosteroid eye drops. The severity of abdominal pain is milder than before and fever is less frequent.
Patient 1 was a 4-year-old boy. At 11 months old, he had been hospitalized for cervical lymphadenitis and then suffered from repeated tonsillitis, cervical lymphadenitis, and bronchitis with elevated serum C-reactive protein (CRP). He was initially suspected of having an immunodeficiency disease but had no abnormalities in neutrophil function, lymphocyte fraction, or immunoglobulin levels. During the fever episodes, no significant pathogens were detected and his fever often improved without antibiotics. Because a single dose of prednisolone (PSL) was effective for the fever, he was diagnosed with periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome based on Thomas’s criteria []. At the age of 4 years and 2 months, fever with pharyngeal redness persisted for 9 days, with PSL not being effective for it. The patient also had temporary nonbacterial coxitis. He had a heterozygous c.574G>A (p.Glu192Lys) variant of TNFAIP3. After undergoing tonsillectomy, the frequency of the fever episodes decreased. His father also suffered from recurrent stomatitis, folliculitis, and hemorrhoids and possessed the same variant of TNFAIP3.