What is a hallmark symptom of lupus?

A hallmark symptom of lupus is the butterfly rash, also known as a malar rash. This characteristic rash appears on the cheeks and across the bridge of the nose, resembling the shape of a butterfly. It is a distinctive feature of systemic lupus erythematosus (SLE), the most common form of lupus, and can be triggered or exacerbated by sun exposure.

The presence of this rash is significant for diagnosis, and it often reflects the autoimmune nature of the disease, where the body's immune system mistakenly attacks its own tissues. While other symptoms such as joint swelling, cognitive impairment, and muscle spasms may occur in individuals with lupus, the butterfly rash is unique and serves as a key clinical indicator that helps healthcare providers in recognizing and diagnosing this condition.