## **Core Concept**
The question describes an infant with erythematous lesions on the cheek and extensor aspects of limbs, and a maternal history of bronchial asthma. This presentation suggests an atopic or allergic condition. Atopic dermatitis, also known as eczema, is a chronic inflammatory skin condition characterized by dry, itchy skin and is often associated with a family history of atopy, which includes conditions like asthma, allergic rhinitis, and atopic dermatitis.

## **Why the Correct Answer is Right**
The correct answer, **Atopic dermatitis (Eczema)**, fits the description provided. Atopic dermatitis commonly presents in infancy with erythematous, scaly patches on the cheeks, forehead, and extensor surfaces of the limbs. A family history of atopy, such as the mother's bronchial asthma, increases the likelihood of atopic dermatitis in the infant. The condition is associated with **IgE-mediated hypersensitivity** and involves a complex interplay of **genetic predisposition**, **environmental factors**, and **immune system dysregulation**.

## **Why Each Wrong Option is Incorrect**
- **Option A:** Psoriasis is a chronic autoimmune skin condition that can present with erythematous plaques, but it typically involves the extensor surfaces in infants and young children, and while it can have a familial component, it's less directly linked to asthma than atopic dermatitis.
- **Option B:** Contact dermatitis is a type of skin inflammation caused by contact with irritants or allergens. While it can cause erythematous lesions, it doesn't typically have a familial atopic predisposition like asthma.
- **Option C:** Seborrheic dermatitis is another skin condition that presents with erythematous, scaly patches but is more commonly associated with oily areas of the body and doesn't have as strong a link to atopic conditions like asthma.

## **Clinical Pearl / High-Yield Fact**
A key clinical pearl is that the presence of **atopic march** should be considered in infants with eczema, especially if there's a family history of atopy. The atopic march refers to the progression from atopic dermatitis to other allergic diseases such as asthma and allergic rhinitis. Early recognition and management of atopic dermatitis can potentially modify the atopic march.

## **Correct Answer:** . Atopic dermatitis (Eczema)