Which condition is indicated by a "bull's eye" rash?

The "bull's eye" rash, also known as erythema migrans, is a classic sign of Lyme disease, which is caused by the Borrelia burgdorferi bacteria transmitted through the bite of infected ticks. This rash typically appears as a red circle surrounding a central area that may be lighter in color, resembling a target or bull’s eye, and can expand over time. It often develops within days or weeks after the tick bite and is usually accompanied by other symptoms such as fever, headache, fatigue, and muscle aches.

The other conditions listed do not typically present with a "bull's eye" rash. For instance, psoriasis presents as red, scaly patches commonly on the elbows and knees, while lupus can cause various skin manifestations but not specifically a bull's eye, often indicating a butterfly rash across the cheeks and nose. Eczema is characterized by itchy, inflamed patches of skin but does not resemble the bull's eye pattern. Understanding these distinctive features helps in identifying Lyme disease and differentiating it from other dermatological conditions.