Differentiating Autoimmune Hepatitis From Sulfasalazine Toxicity: The Value of Clinicopathologic Correlation

Sulfasalazine is one of the commonly used disease-modifying anti-rheumatic drugs (DMARDs) for many inflammatory and autoimmune illnesses. Sulfasalazine is generally safe with consistent monitoring, as it can rarely cause clinically significant drug‑induced liver injury (DILI). Diagnosing DILI can be challenging in patients with autoimmune diseases due to positive baseline autoantibodies that may mimic autoimmune hepatitis (AIH) or lupus‑associated hepatitis. This case highlights severe hepatocellular DILI temporally associated with sulfasalazine exposure in a patient with Sjögren's disease and systemic lupus erythematosus (SLE), where positive antinuclear antibody (ANA) could have misleadingly suggested an autoimmune liver disease. Clinical course, targeted serologies, imaging, and histology supported sulfasalazine‑induced liver toxicity rather than autoimmune or viral hepatitis. Early recognition and discontinuation of the drug were associated with rapid clinical and biochemical improvement in liver function.