‘Malignant pustule’ is –
**Core Concept**
The term 'malignant pustule' refers to a cutaneous lesion resulting from an infectious process, specifically caused by **Bacillus anthracis**. This condition is a manifestation of **anthrax**, a zoonotic disease. The 'malignant pustule' is characterized by a painless, ulcerative lesion with a characteristic black eschar.
**Why the Correct Answer is Right**
The correct answer is related to the definition of 'malignant pustule' as it pertains to the cutaneous form of **anthrax**. The lesion begins as a painless, pruritic papule that eventually ulcerates and forms a black eschar. **Bacillus anthracis** spores enter the body through cuts or scratches in the skin, leading to this condition.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect as it does not relate to the definition of 'malignant pustule'.
**Option B:** Incorrect because, although it might be related to skin conditions, it is not the specific cause of 'malignant pustule'.
**Option C:** Incorrect as this option does not accurately describe the 'malignant pustule'.
**Option D:** Incorrect because, like the other options, it does not correctly identify the 'malignant pustule'.
**Clinical Pearl / High-Yield Fact**
The 'malignant pustule' is a key clinical feature of cutaneous **anthrax**, and its recognition is crucial for prompt diagnosis and treatment. A high index of suspicion is necessary, especially in individuals who work with animals or handle animal products.
**Correct Answer:** D. Cutaneous anthrax.