**Core Concept**
The patient's symptoms suggest a skin condition characterized by a specific pattern of grouped papulovesicular lesions accompanied by intense itching, which is a hallmark of an autoimmune-mediated skin disorder.

**Why the Correct Answer is Right**
The description points towards **Pityriasis Rosea**, a common skin condition caused by reactivation of human herpesvirus 6 and 7 (HHV-6 and HHV-7). The lesions are typically arranged in a Christmas tree pattern on the trunk and proximal extremities, and are accompanied by intense pruritus. The condition is often preceded by a herald patch, which may appear days or weeks before the full-blown eruption.

**Why Each Wrong Option is Incorrect**
* **Option A:** **Psoriasis** typically presents with red, scaly plaques on elbows, knees, and scalp, but is not characterized by grouped papulovesicular lesions or a Christmas tree distribution.
* **Option B:** **Dermatitis Herpetiformis** is a skin manifestation of celiac disease, characterized by intensely itchy, grouped blisters on the elbows, knees, and buttocks, but it is not typically associated with a Christmas tree distribution.
* **Option C:** **Seborrheic Dermatitis** presents with scaly, oily patches on the scalp, face, and torso, but does not typically cause grouped papulovesicular lesions or intense itching.

**Clinical Pearl / High-Yield Fact**
Pityriasis Rosea is a self-limiting condition that usually resolves on its own within 6-8 weeks, but the intense itching and discomfort can be managed with topical corticosteroids, oral antihistamines, and phototherapy.

**Correct Answer: B. Dermatitis Herpetiformis**