A patient presented with blisters. Histopathological examination is shown below. The diagnosis is:
**Core Concept**
The underlying principle in this question is the histopathological diagnosis of blistering skin diseases. The patient's presentation of blisters necessitates a thorough examination of the skin biopsy to determine the specific disease process involved.
**Why the Correct Answer is Right**
The histopathological examination shows a subepidermal blister with a band of inflammatory cells, indicating the presence of a subepidermal autoimmune blistering disease. This is characteristic of **Pemphigoid**, a group of autoimmune diseases that involve the formation of autoantibodies against proteins in the basement membrane zone of the skin. The autoantibodies lead to the activation of complement and the subsequent deposition of inflammatory cells, resulting in the formation of blisters.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe the histopathological findings. The absence of autoantibodies and inflammatory cells in the epidermis is not consistent with this diagnosis.
**Option B:** This option is incorrect because it is a different type of autoimmune blistering disease that involves the formation of autoantibodies against proteins in the epidermis, rather than the basement membrane zone.
**Option C:** This option is incorrect because it is a non-autoimmune cause of blistering skin disease, and the histopathological findings do not indicate a primary epidermal process.
**Clinical Pearl / High-Yield Fact**
A key feature of pemphigoid is the presence of a band of inflammatory cells at the dermal-epidermal junction, which can be visualized on direct immunofluorescence studies. This is a critical diagnostic clue that can help differentiate pemphigoid from other autoimmune blistering diseases.
**Correct Answer:** Pemphigoid