LAUSR

Immunoglobulin A (IgA) vasculitis mainly affects the joints, skin, kidneys, and gastrointestinal tract; however, purpura is an essential diagnostic criterion. Here, we report an unusual case of IgA vasculitis without purpura in an elderly woman. A 76-year-old woman was admitted to our hospital complaining of diarrhea and abdominal pain. No skin rash, purpura, jaundice, or peripheral lymphadenopathy was observed. Endoscopy of the small intestine revealed severe mucosal sloughing in the duodenum, and a biopsy specimen showed severe erosive duodenitis. A decrease in coagulation factor XIII (FXIII) activity was also observed during laboratory blood tests. IgA immunostaining revealed granular IgA deposition on the walls of the interstitial small blood vessels. Although the patient showed no purpura or renal involvement, a diagnosis of IgA vasculitis was made based on the histopathology findings from biopsies. The administration of purified FXIII concentrate improved her symptoms immediately and facilitated regeneration of the duodenal villi. When gastroenterologists encounter severe erosive duodenitis or inflammation of the small intestine, IgA vasculitis should be listed as part of the differential diagnosis even without purpura and/or renal involvement. For a definitive diagnosis, measurement of FXIII and IgA immunostaining using duodenal biopsy specimens should be performed actively.