**Core Concept**
Atopic dermatitis, also known as eczema, is a chronic inflammatory skin condition characterized by recurring episodes of dry, itchy, and scaly skin, often accompanied by other atopic diseases such as asthma and allergic rhinitis. It is a complex condition involving genetic predisposition, environmental triggers, and an impaired skin barrier function.

**Why the Correct Answer is Right**
The patient's symptoms of recurrent episodes of flexural eczema, contact urticaria, and recurrent skin infections are classic manifestations of atopic dermatitis. The condition is often associated with an increased susceptibility to skin infections due to the compromised skin barrier function. Furthermore, the patient's severe abdominal cramps and diarrhea upon consuming seafood suggest an underlying allergic response, which is consistent with the atopic tendency.

**Why Each Wrong Option is Incorrect**
**Option A:** Seborrheic dermatitis typically presents with greasy, yellowish, scaly patches on the scalp, face, and trunk, which does not match the patient's symptoms.

**Option C:** Airborne contact dermatitis, also known as allergic contact dermatitis, is caused by an allergic reaction to airborne allergens, and it usually presents with localized skin lesions, not the widespread symptoms described in the patient.

**Option D:** Nummular dermatitis, also known as discoid eczema, presents with coin-shaped patches of dry, itchy skin, which is not consistent with the patient's symptoms of flexural eczema and contact urticaria.

**Clinical Pearl / High-Yield Fact**
Atopic dermatitis often co-exists with other atopic diseases, such as asthma and allergic rhinitis, due to the underlying genetic predisposition and environmental triggers. A thorough medical history and physical examination are essential in diagnosing and managing this condition.

**✓ Correct Answer: B. Atopic dermatitis**