Erythema annulare centrifugum
Contrary to this picture, it is more common for the lesion to have no scaling.
References
Erythema annulare centrifugum (EAC) is an annular, erythematous lesion that appears as urticarial-like papules and enlarges centrifugally, then clears centrally. A fine scale is sometimes present inside the advancing edge, known as a trailing scale. Erythema annulare centrifugum is classified as a reactive erythema and has been associated with various underlying conditions, including malignancies. When erythema annulare centrifugum occurs as a paraneoplastic phenomenon, it has been designated PEACE (paraneoplastic erythema annulare centrifugum eruption). PEACE is more commonly seen in females, typically precedes the clinical diagnosis of malignancy, and may recur with subsequent relapses. EAC is one of the three major figurate erythemas, with EAC being the most common. These dermatoses share the common presentation of advancing erythematous, annular lesions, but are each separated by unique clinical and histopathologic characteristics. Once the other major figurate erythemas (erythema marginatum, erythema migrans, and erythema gyratum repens) are excluded, EAC often becomes a diagnosis of exclusion.
Erythema annulare centrifugum (EAC) is a type of red rash that forms circular shapes and often has flaky skin. It's thought to be triggered by various factors, but we're not sure exactly how it happens. On average, the rash lasts for about 11 months. We discuss a patient who has had EAC coming back for 50 years without a clear reason. While it does seem to come back at certain times of the year, this case represents the longest reported duration of EAC.
Occurring at any age these lesions appear as raised pink-red ring or bulls-eye marks. They range in size from 0.5–8 cm (0.20–3.15 in). The lesions sometimes increase size and spread over time and may not be complete rings but irregular shapes.
A skin biopsy can be performed to confirm the disease. The lesions may last from anywhere with an average duration of 11 months. It usually doesn't require treatment, but topical steroids may be helpful in reducing redness, swelling and itchiness.