Which of the following conditions do not cause purpura: amyloidosis, vitamin D deficiency, thrombocytosis, nodular sclerosis, polycythemia?

Which Conditions Do NOT Cause Purpura

Vitamin D deficiency, thrombocytosis, nodular sclerosis, and polycythemia do NOT typically cause purpura, while amyloidosis can cause purpura through vascular fragility.

Understanding Purpura Mechanisms

Purpura results from either:

• Thrombocytopenia (low platelet count causing bleeding into skin) 1
• Platelet dysfunction (abnormal platelet function despite normal counts) 1
• Vascular fragility (vessel wall damage allowing blood extravasation) 1

Analysis of Each Condition

Amyloidosis (DOES Cause Purpura)

• Amyloidosis causes purpura through vascular infiltration, where amyloid protein deposits in blood vessel walls create fragility and lead to spontaneous bleeding into skin 2
• This mechanism is independent of platelet count or function 2

Vitamin D Deficiency (Does NOT Cause Purpura)

• Vitamin D deficiency is NOT associated with purpura or bleeding disorders 3
• While vitamin D deficiency is prevalent in various hematologic conditions (found in 56.6% of AL amyloidosis patients and 66.7-74.2% of myeloproliferative disorder patients), it represents a concurrent finding rather than a cause of bleeding 2, 4
• The one exception is severe vitamin B12 deficiency (not vitamin D) combined with hyperhomocysteinemia, which can rarely cause hemolytic anemia and thrombocytopenia—but this is a B12 issue, not vitamin D 5, 6

Thrombocytosis (Does NOT Cause Purpura)

• Thrombocytosis (elevated platelet count) does not cause purpura; instead, it increases thrombosis risk 1
• Essential thrombocythemia, a myeloproliferative disorder with markedly elevated platelets, causes microvascular occlusion and arterial/venous thrombosis, not bleeding manifestations 1
• Polycythemia vera may display thrombocytosis as a concurrent finding, but bleeding complications arise from other mechanisms, not the elevated platelet count itself 1, 7

Nodular Sclerosis (Does NOT Cause Purpura)

• Nodular sclerosis (a subtype of Hodgkin lymphoma) does not directly cause purpura 8
• Lymphoproliferative disorders can cause secondary immune thrombocytopenia through bone marrow infiltration or autoimmune mechanisms, but nodular sclerosis itself is not a recognized cause of purpura 1, 9, 8

Polycythemia (Does NOT Cause Purpura)

• Polycythemia vera causes thrombosis, not purpura 1
• Major symptoms relate to arterial hypertension and arterial/venous thrombosis, with strokes potentially being the first manifestation 1
• While polycythemia vera is a myeloproliferative disorder that may have concurrent thrombocytosis, the primary clinical concern is thrombotic complications, not bleeding 1, 7
• The exception is cyanotic congenital heart disease with secondary polycythemia, which causes mild thrombocytopenia (100,000-150,000/μL) through platelet consumption triggered by hyperviscosity—but this is thrombocytopenia causing potential purpura, not polycythemia directly 9

Critical Clinical Distinction

The key pathophysiologic principle: Purpura requires either low platelets, dysfunctional platelets, or fragile vessels 1. Conditions that increase platelet counts (thrombocytosis) or red blood cell mass (polycythemia) create hypercoagulable states with thrombosis risk, not bleeding 1.

Answer to the Question

Options b (vitamin D deficiency), c (thrombocytosis), d (nodular sclerosis), and e (polycythemia) do NOT cause purpura. Only amyloidosis (option a) is a recognized cause of purpura through vascular infiltration and fragility 2.