Systemic lupus erythematosus is an autoimmune inflammatory connective tissue disease involving multiple organs that occurs mostly in young women, with an increasing number of early, mild and atypical cases. Pharmacologic lupus is similar to systemic lupus erythematosus, but has many differences, mainly as follows: 1. Pharmacologic lupus does not necessarily meet the lupus diagnostic criteria of the ACR. 2. Patients with pharmacologic lupus have other disease manifestations for which the patient is taking a certain drug, such as penicillamine for patients with rheumatoid arthritis and hydrazidiazine or methyldopa for patients with hypertension, in order to treat the disease. 3. Patients with pharmacologic lupus are older than patients with systemic lupus erythematosus. 4. There is no female predominance in patients with drug-related lupus. 5. The symptoms of drug-related lupus are mild, with systemic symptoms, arthritis, pleurisy and pericarditis, similar to those of senile systemic lupus erythematosus. These symptoms are reversible and gradually disappear after stopping the drugs. 6. Both drug lupus and systemic lupus can have positive ANA and LE cells, but anti-ds-DNA antibodies and anti-Sm antibodies are rare in drug lupus.