Drug-Induced Systemic Lupus Erythematosus

On the credit side of the iatrogenic disease ledger are disclosures occasionally made by drug-induced symptoms, which reveal a latent disease or an unsuspected genetic abnormality. Steroids may unmask inactive tuberculosis or latent diabetes. Barbiturates may bring to light dormant porphyria. And primaquine-induced hemolytic anemia may give the first clue to glucose-6-phosphate dehydrogenase deficiency in red blood cells.

The promptness with which a drug exposes a latent disease or a genetic trait, and, in the latter case, the actual identification of the enzymatic defect, leave no doubt that the drug has truly unmasked a preexisting condition. But can we be sure of unmasking when no enzymatic error has been demonstrated and when the drug has been taken for a prolonged period before the disease becomes evident? Might not the disease then be simply a toxic effect of the drug rather than an activated, genetically determined diathesis?

These questions may find