## **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 personal or family history of atopy, which includes conditions like asthma, allergic rhinitis, and atopic dermatitis.

## **Why the Correct Answer is Right**
Atopic dermatitis typically 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 a defective skin barrier and an imbalance in the immune response, leading to inflammation and the characteristic skin lesions.

## **Why Each Wrong Option is Incorrect**
- **Option A:** This option is not provided, but typically, conditions like seborrheic dermatitis or contact dermatitis could be considered. Seborrheic dermatitis usually presents with a yellowish, oily scaling on the scalp and face, not typically on extensor surfaces. Contact dermatitis would have a clear history of exposure to an allergen or irritant.
- **Option B:** Similarly, without the specific details, it's hard to address, but conditions like psoriasis could be a differential. Psoriasis can present with erythematous lesions but usually has a more defined, scaly appearance and can occur on extensor surfaces, but the context of maternal asthma and typical infantile distribution makes it less likely.
- **Option C:** Without specifics, it's challenging, but another condition like scabies could cause erythematous lesions but is usually accompanied by severe pruritus and might involve other family members.

## **Clinical Pearl / High-Yield Fact**
A key point to remember is that atopic dermatitis often follows a "3-stage" evolution: infantile (0-2 years) with lesions on the face and extensor surfaces, childhood (2-10 years) with lesions in flexural areas, and adult with lesions often in flexural areas and sometimes resembling the infantile pattern. A maternal history of asthma/allergies significantly increases the risk.

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