Despite its long history of untoward side effects of a systemic autoimmune disease, drug-induced lupus can be difficult to recognize because of the disconnect between chronic drug usage and onset of symptoms. In this case, the patient was treated with hydralazine for two years when symptoms were initially reported, but a diagnosis of hydralazine-induced lupus was not considered for another half year. Despite treatment with steroidal and nonsteroidal anti-inflammatory medications during this period, rheumatologic symptoms and signs continued to deteriorate, consistent with the diagnosis of systemic lupus erythematosus. Not until the patient voluntarily discontinued hydralazine did symptoms begin to improve, fully resolving over the subsequent 6-12 months largely in the absence of anti-inflammatory medication. This patient demonstrates that failure to recognize a drug-induced disease etiology can result in substantial worsening of rheumatologic symptoms over the subsequent six months, ultimately satisfying criteria for systemic lupus erythematosus. While symptoms and signs largely normalized, some laboratory abnormalities and occasional arthralgia remained two years after discontinuing hydralazine, suggesting smoldering inflammatory disease.
Keywords: Hydralazine; drug-induced lupus; long-term drug exposure.