Auspitz sign is seen in
**Core Concept**
The Auspitz sign is a clinical sign observed in dermatology, characterized by the presence of pinpoint bleeding (petechiae) after the removal of scales from a plaque of psoriasis. This phenomenon is due to the thinning of the epidermis and the presence of dilated capillaries at the dermo-epidermal junction.
**Why the Correct Answer is Right**
The Auspitz sign is a hallmark of psoriasis, an autoimmune skin disorder. The removal of scales from a psoriatic plaque leads to the exposure of the underlying dilated capillaries, causing pinpoint bleeding due to the fragile nature of these blood vessels. The thinning of the epidermis in psoriasis also contributes to this phenomenon.
**Why Each Wrong Option is Incorrect**
**Option A:** The Auspitz sign is not typically seen in eczema (atopic dermatitis), which is characterized by a different set of clinical and histopathological features.
**Option B:** Although the Auspitz sign can be seen in other skin conditions, it is most commonly associated with psoriasis, making this option incorrect.
**Option C:** The Auspitz sign is not a characteristic feature of seborrheic dermatitis, which has a distinct clinical presentation and histopathology.
**Clinical Pearl / High-Yield Fact**
The Auspitz sign is a useful clinical tool for differentiating psoriasis from other skin conditions, but it can also be seen in other conditions such as dermatitis herpetiformis and lichen planus.
**Correct Answer: D. Psoriasis**