What Is not true about Erythema multiforme
**Core Concept**
Erythema multiforme (EM) is a skin condition characterized by the appearance of target lesions, typically in response to an infectious or inflammatory trigger. It is often associated with infections, such as herpes simplex virus or Mycoplasma pneumoniae, and is also linked to autoimmune disorders.
**Why the Correct Answer is Right**
The correct answer is related to the pathophysiology and clinical presentation of EM. EM is a type of hypersensitivity reaction, which is mediated by T cells and antibodies. The target lesions of EM are thought to result from the interaction of immune cells with the skin, leading to the release of inflammatory mediators and damage to the skin. **Key features of EM include the presence of target lesions, which are characterized by a central area of necrosis surrounded by an outer ring of inflammation and an inner ring of edema.**
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because EM is indeed associated with infections, such as herpes simplex virus, which is a common trigger for the condition.
* **Option B:** This option is incorrect because EM can be recurrent, and it is often linked to autoimmune disorders, such as lupus or rheumatoid arthritis.
* **Option C:** This option is incorrect because EM is characterized by the presence of target lesions, which are a hallmark of the condition.
**Clinical Pearl / High-Yield Fact**
A key feature of EM is its association with other autoimmune disorders, such as lupus or rheumatoid arthritis. Physicians should consider EM in the differential diagnosis of patients with a history of autoimmune disorders or those who present with skin lesions accompanied by systemic symptoms.
**Correct Answer: D.**