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

The presence of a "bull's eye" lesion is characteristic of Lyme disease, which is caused by the bite of infected black-legged ticks. This lesion often appears as a circular, red rash with a clearer center, resembling a target or bull's eye. The medical term for this rash is erythema migrans, and it typically develops within a few days to a month after the tick bite. Recognizing this distinct pattern is crucial for early diagnosis and treatment of Lyme disease, as timely intervention can prevent more severe complications.

In contrast, psoriasis is an autoimmune condition that results in thick, scaly patches on the skin, but does not typically exhibit the bull's eye appearance. Dermatitis is a broad term for inflammation of the skin, which can present in various forms but lacks the defined target pattern. Eczema, which is also a form of dermatitis, features dry, itchy, and inflamed skin, and similarly does not present as a bull's eye lesion. Hence, the specific appearance of a bull's eye lesion points directly to Lyme disease as the correct answer.