In simple words: Erythema annulare centrifugum is a skin condition that causes expanding red rings or circles on the skin.These rings are usually not itchy or painful.Doctors often determine the diagnosis based on the appearance of the rash, but sometimes further tests might be needed to rule out other problems.

Erythema annulare centrifugum (EAC) is a relatively uncommon skin disorder manifesting as annular (ring-shaped) or circinate (circular) erythematous (reddened) plaques that gradually enlarge centrifugally (away from the center).These lesions are typically asymptomatic or mildly itchy.The etiology is often unknown, although several associations have been noted, including infections (bacterial, viral, fungal, parasitic), inflammatory conditions, medications, and malignancies.Diagnosis relies on clinical presentation, and in some cases, further investigations might be necessary to rule out other conditions.

Example 1: A 35-year-old female presents with a slowly enlarging, ring-like rash on her arms.The lesion is not itchy.Physical examination reveals an erythematous plaque with a central clearing, consistent with EAC. No further investigations are deemed necessary., A 60-year-old male with a history of diabetes and hypertension presents with multiple annular erythematous lesions on his trunk. He reports mild itching. A detailed history and physical examination are performed, and blood work is ordered to rule out other underlying causes., A 20-year-old female presents with a similar rash following a recent viral infection.The diagnosis of EAC is made after ruling out other possibilities. Treatment focuses on supportive care, such as emollients, to manage any mild itching.

Complete medical history, including details of any recent infections, medications, or other medical conditions.Thorough description of the rash, including location, size, duration, and any associated symptoms. Photographs of the lesions are helpful for documentation and tracking changes over time.

** EAC is a diagnosis of exclusion.It is important to consider other conditions with similar presentations before establishing a diagnosis of EAC. Treatment is primarily symptomatic, with options including emollients or topical corticosteroids for itching.In cases associated with underlying medical conditions, treatment focuses on managing those conditions.