Which statement about polyarteritis nodosa is true?

Which statement about polyarteritis nodosa is true?

• A. Compared to others, PN commonly involves the lungs.
• B. PN is a disease of small vessels with eosinophilia.
• C. Medium-sized vessel vasculitis with immune complex deposition and fibrinoid necrosis.
• D. PN never correlates with Hepatitis B infection.

Answer: (C)

Polyarteritis nodosa is a medium-sized vessel vasculitis characterized by transmural inflammation with fibrinoid necrosis and often immune complex deposition, especially in cases linked to Hepatitis B infection. This pattern explains why the statement describing it as a medium-sized vessel vasculitis with immune complex deposition and fibrinoid necrosis is true. PAN typically spares the lungs, so claims of predominant lung involvement are inaccurate. It is not a disease of small vessels, and eosinophilia is not a defining feature of PAN (that finding is more associated with other vasculitides). While Hepatitis B can be associated with PAN due to immune complex formation, PN can occur without HBV, so a statement saying it never correlates with HBV is incorrect.

Polyarteritis nodosa is a medium-sized vessel vasculitis characterized by transmural inflammation with fibrinoid necrosis and often immune complex deposition, especially in cases linked to Hepatitis B infection. This pattern explains why the statement describing it as a medium-sized vessel vasculitis with immune complex deposition and fibrinoid necrosis is true. PAN typically spares the lungs, so claims of predominant lung involvement are inaccurate. It is not a disease of small vessels, and eosinophilia is not a defining feature of PAN (that finding is more associated with other vasculitides). While Hepatitis B can be associated with PAN due to immune complex formation, PN can occur without HBV, so a statement saying it never correlates with HBV is incorrect.