IgG4-related disease presenting with gastric outlet obstruction.

A woman in her 20s presented with 6 weeks of fever, persistent vomiting and 28% loss of body weight. Symptoms were refractory to treatment with antiemetics and broad spectrum antibiotics.Further investigation via oesophageogastroduedenoscopy revealed a large gastric ulcer and pyloric stricture, causing gastric outlet obstruction (GOO). Biopsies of the stomach and duodenum showed plasma cell infiltration with a large proportion being IgG4 positive.Treatment with methylprednisolone, and later prednisolone, quickly improved inflammatory markers and symptoms. Balloon dilatation of the pyloric stricture also improved vomiting, allowing eventual re-establishment of oral nutrition. The patient made a full recovery with maintenance treatment on mycophenolate mofetil.IgG4-related disease (IgG4-RD) is a multisystem disorder with unpredictable presentation. The case highlights diagnostic challenges in IgG4-RD and identifies it as a rare differential in upper gastrointestinal symptoms. To our knowledge this is the first published case of IgG4-RD in the duodenum causing GOO.