Coexistence of IgG4-related disease and tubercular lymphadenopathy in a rheumatoid arthritis patient

Abstract

Extrapulmonary tuberculosis is a very common cause of generalised lymphadenopathy especially in tuberculosis endemic regions like India. A 33-year-old lady who had been diagnosed with rheumatoid arthritis 5 years back and had received treatment with biologicals including adalimumab presented with a 3 week history of persistent fever associated with significant weight loss and abdominal fullness. Investigations pointed towards a picture of tubercular aetiology although, a definite microbiological diagnosis was not possible at this stage. Patient also had an underlying subacute thyroiditis with diffusely increased uptake in Tc99 scan. Considering the background risk factor of use of biologicals and typical clinical presentation resembling tuberculosis, a decision to start antitubercular therapy was taken. The fever resolved but it recurred after 2 weeks and then after an extensive workup, the diagnosis of coexistent IgG4-related disease along with microbiological diagnosis of tuberculosis was established. This case highlights the importance of an active search for coexistent pathologies in cases of lymphadenopathy with insufficient response to standard therapy.