Undiagnosed Fever in a TB Contact Patient: An Unusual Cause.

IgG4-Related Disease(IgG4-RD) is a rare disease that can present with myriad clinical features. We report a tuberculosis contact case who presented with fever and constitutional complaints with imaging evidence of paravertebral and retroperitoneal soft tissue thickening. Further workup, including tissue biopsy ruled out tuberculosis and revealed diagnosis to be IgG4-related disease. Patient was started on oral steroids, which led to symptomatic improvement. In a TB endemic country such as ours, for a patient presenting with pleural and/or peritoneal fibrosis, a differential diagnosis of IgG4-RD must be kept.