Question

Palpable purpura may be seen in the following EXCEPT

• A. Scurvy
• B. Acute meningococcemia
• C. Vasculitis
• D. Essential mixed cryoglobulinemia

Hint:

Ask which one of these damages capillaries without actually inflaming the vessel wall.

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
The question asks which listed condition does not cause palpable purpura, meaning it produces a flat, non-palpable purpuric lesion instead.

Step 2: Key Concept or Approach:
Palpable purpura results from inflammation of the vessel wall, vasculitis, with blood extravasating into a thickened, infiltrated dermis, so the lesion can be felt as raised. Conditions that cause simple capillary fragility or platelet-related bleeding without vessel wall inflammation instead give flat, non-palpable purpura or petechiae.

Step 3: Working Through the Options:
Scurvy is caused by vitamin C deficiency, which impairs collagen cross-linking and weakens capillary walls, producing classic perifollicular, non-palpable petechiae and purpura, often with corkscrew hairs, rather than a vasculitic, palpable lesion. Acute meningococcemia causes a vasculitic and DIC-driven purpura that is classically palpable and can progress to purpura fulminans. Vasculitis, by definition, inflames the vessel wall and produces the textbook palpable purpura, typically over the lower legs. Essential mixed cryoglobulinemia deposits immune complexes in small vessels, causing a leukocytoclastic vasculitis with palpable purpura.

Step 4: Conclusion:
Scurvy is the exception that does not cause palpable purpura, so scurvy is correct.