In PAN, which vessel is typically spared?

In PAN, which vessel is typically spared?

• A. Pulmonary arteries
• B. Renal arteries
• C. Coronary arteries
• D. Carotid arteries

Answer: (A)

Pulmonary arteries are typically spared in polyarteritis nodosa. This disease causes necrotizing inflammation of medium-sized arteries, most often hitting renal, mesenteric, hepatic, and sometimes coronary arteries, leading to hypertension, abdominal pain from mesenteric ischemia, and possible myocardial ischemia. The lungs, however, are usually not involved, so the pulmonary vasculature remains unaffected in the classic pattern. This sparing helps differentiate PAN from other vasculitides like granulomatosis with polyangiitis or microscopic polyangiitis, where lung involvement and capillaritis are more common. Rarely PAN can involve the lungs, but that is not the typical presentation.

Pulmonary arteries are typically spared in polyarteritis nodosa. This disease causes necrotizing inflammation of medium-sized arteries, most often hitting renal, mesenteric, hepatic, and sometimes coronary arteries, leading to hypertension, abdominal pain from mesenteric ischemia, and possible myocardial ischemia. The lungs, however, are usually not involved, so the pulmonary vasculature remains unaffected in the classic pattern. This sparing helps differentiate PAN from other vasculitides like granulomatosis with polyangiitis or microscopic polyangiitis, where lung involvement and capillaritis are more common. Rarely PAN can involve the lungs, but that is not the typical presentation.