En coup de sabre lesion is seen in ?
**Core Concept**
En coup de sabre lesion is a type of linear atrophoderma of Pasini and Pasini, characterized by a linear depression of the skin, typically on the cheek. This condition is associated with autoimmune disorders and is believed to be a manifestation of the underlying immune system dysregulation.
**Why the Correct Answer is Right**
En coup de sabre lesion is commonly seen in patients with autoimmune disorders, particularly in those with autoimmune hemolytic anemia, systemic lupus erythematosus, and other connective tissue diseases. The exact pathogenesis is not fully understood, but it is thought to be related to the deposition of immune complexes in the dermis, leading to inflammation and tissue damage.
**Why Each Wrong Option is Incorrect**
**Option A:** En coup de sabre lesion is not typically associated with neurocutaneous disorders such as neurofibromatosis, which can cause other types of skin lesions.
**Option B:** While autoimmune disorders are a common association, en coup de sabre lesion is not a manifestation of an allergic reaction or an immune response to a specific antigen.
**Option C:** En coup de sabre lesion is not a type of skin cancer or a malignant condition, but rather a benign lesion.
**Clinical Pearl / High-Yield Fact**
When evaluating a patient with a linear atrophoderma, it is essential to consider the possibility of an underlying autoimmune disorder and to perform a thorough history and physical examination to identify other associated symptoms or signs.
**Correct Answer: D. Linear atrophoderma of Pasini and Pasini.**