Systemic lupus erythematosus is a chronic, relapsing autoimmune disease that can affect multiple organ systems. An increased prevalence of drug allergy has been reported in lupus patients compared with the general population. Using a cohort of 417 lupus patients, we found a history of sulpha allergy in 27.3% of patients. European-American lupus patients with sulpha allergy are about two times more likely to suffer from lymphopenia, two times more likely to have anti-Ro autoantibody, and four times less likely to have anti-nRNP antibodies compared with lupus patients without a reported sulpha allergy (P = 0.0075, 0.025, and 0.032, respectively). In African-American lupus patients, a history of sulpha allergy was associated with over three times increased odds of developing pericarditis (P = 0.005).