A Case of Seronegative ANA Hydralazine-Induced Lupus Presenting With Pericardial Effusion and Pleural Effusion.

Hydralazine induced lupus syndrome (HILS), a form of Drug-Induced Lupus (DIL), was first reported in 1953. Since then, studies have shown an increasing incidence of HILS. It presents with lupus-like symptoms such as arthralgia, fever, chest pain, anorexia, fatigue, petechiae, and rash. Though rare, HILS may initially present with pericardial effusion. Lab findings of HILS usually show positive anti-nuclear antibody (ANA) in >95% of cases, antihistone abs in >95% of cases, rheumatoid factor ab in 20%, and anti-double-strand DNA in <5%. Herein we present a case of HILS which initially presented with a seronegative ANA and pericardial effusion. An 82-year-old woman who presented with shortness of breath was found to have bilateral pleural effusion and pericardial effusion. Common etiologies of pericardial effusion have been ruled out, after careful review of her home medications, hydralazine was suspected to be the culprit of her pericardial effusion. Initial ANA testing was negative, however given high clinical suspicion autoimmune disease screening was done revealing positive anti-histone antibodies. Hydralazine was deemed to be the etiology of her pericardial effusion which led to the discontinuation of the drug. Serial echocardiography revealed no recurrence of the effusion.