Pyoderma gangrenosum, acne, and unclassified inflammatory bowel disease syndrome

Abstract

Abstract Rationale: Pyogenic arthritis, pyoderma gangrenosum (PG), and acne (PAPA) syndrome is an autosomal dominant inherited autoinflammatory syndrome. Recently, many subtypes of PAPA syndrome have been reported, such as PG, acne, and ulcerative colitis (PAC) syndrome. We present the rare case of a patient with intestinal lesions different from those seen in the patient with PAC syndrome. Patient concerns: A 22-year-old Japanese man was referred to our department for arthralgia, PG, and acne. He was diagnosed with inflammatory bowel disease 3 months after the first visit. Diagnoses: Synovial tissue from the patient's knee joint was poor in neutrophil infiltration, which did not indicate pyogenic arthritis. His symptoms resembled those of PAC syndrome; however, the macroscopic findings indicated unclassified inflammatory bowel disease rather than ulcerative colitis or Crohn's disease. We diagnosed him with PG, acne, and unclassified inflammatory bowel disease syndrome, which we propose to be a new subtype of PAPA syndrome. Interventions: Initially, the patient was treated with steroids, salazosulfapyridine, and enteral feeding, but arthralgia, acne, abdominal symptoms, and exacerbation of inflammatory reactions were still observed. Administration of adalimumab and granulocyte and monocyte adsorption apheresis therapy were not effective, and we elected to administer infliximab as an alternative treatment. Outcomes: All clinical symptoms except arthralgia improved after administration of infliximab. Lessons: We consider PG, acne, and unclassified inflammatory bowel disease to be a new subtype of PAPA syndrome complicated with unclassified inflammatory bowel disease, associated with autoinflammatory-related enterocolitis.