Child has lesion on buttocks since 2 year spreading peripherally with central scarring non symptomatic diagnosis-
**Core Concept**
Erythema annulare centrifugum (EAC) is a rare, benign skin condition characterized by a peripheral spread of annular lesions with central scarring. It is often asymptomatic and can occur in various age groups, including children.
**Why the Correct Answer is Right**
The peripheral spread of annular lesions with central scarring is a hallmark feature of EAC. This condition is thought to result from an abnormal immune response to an underlying infection or inflammation, leading to the formation of a distinctive annular pattern. The lesions of EAC often have a central clearing, which is a result of the body's attempt to eliminate the inciting antigen. EAC can be challenging to diagnose, and the clinical presentation can mimic other skin conditions.
**Why Each Wrong Option is Incorrect**
**Option A:** Erythema migrans is a distinct skin condition associated with Lyme disease, characterized by a single, expanding annular lesion with central clearing, but it is not typically non-symptomatic and lacks central scarring.
**Option B:** Erythema migrans is a different condition from the one described, and this option seems to be a repetition of the condition in option A.
**Option C:** Erythema marginatum is a rash associated with acute rheumatic fever, characterized by a non-pruritic, evanescent, and marginal rash, which is quite different from EAC.
**Option D:** Erythema gyratum repens is a rare skin condition characterized by a wavelike, annular pattern, often associated with underlying malignancies, which is not similar to the peripheral spread of EAC.
**Clinical Pearl / High-Yield Fact**
Erythema annulare centrifugum can be challenging to diagnose, and a high index of suspicion is required. It is essential to consider this condition in the differential diagnosis of annular skin lesions, especially in children and adolescents.
**✓ Correct Answer: A. Erythema annulare centrifugum**