The early characteristic rash of lupus erythematosus is typically a butterfly-shaped rash on the face. Other common presentations include palm and periungual erythema, discoid rash, nodular erythema, and livedo reticularis. If the rash is not notably itchy, it generally indicates lupus erythematosus. If there is significant itching, it may suggest the possibility of an allergic factor active in the disease. After immunosuppression, itchy rashes should be monitored for possible fungal infections. The specific pathogenesis of systemic lupus erythematosus is still unclear. If a patient exhibits the typical butterfly-shaped rash on the face, systemic lupus erythematosus should be highly suspected. Testing for antinuclear antibodies, and specifically for anti-Sm and double-stranded DNA antibodies, which represent a variety of autoantibodies, can diagnose systemic lupus erythematosus.