[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [General pathology](https://durgical.com/en/general-pathology/) › [Blood vessels](https://durgical.com/en/general-pathology/areas/vessels/) › Medium-vessel vasculitis # Medium-vessel vasculitis - Lesion Three diseases of medium arteries: one tears holes in visceral arteries, one hits the coronaries of small children, one closes the limb vessels of smokers. Updated Nov 12, 2026 ## Key points - PAN: lesions of different ages side by side (acute fibrinoid necrosis next to healed fibrosis); microaneurysms (‘rosary’ on angiography); no glomerulonephritis, no lung involvement. - PAN: young adults; hepatitis B in a minority; renal artery involvement causes hypertension and infarcts, not glomerulonephritis. - Kawasaki: under 5; fever at least five days, conjunctivitis, red cracked lips and strawberry tongue, rash, swollen red hands and feet with later peeling, cervical node. - Kawasaki: the leading cause of acquired heart disease in children in many countries; coronary aneurysms may thrombose or rupture. - Buerger: young men who smoke heavily; claudication of the foot instep, Raynaud, migratory superficial phlebitis, digital ulcers and gangrene; stopping smoking halts it. ## What it is Medium-vessel vasculitis targets the main visceral arteries and their branches. Polyarteritis nodosa (PAN) is a segmental necrotizing arteritis of kidneys, gut, nerves and skin that spares the lungs and is not ANCA-associated; some cases follow hepatitis B. Kawasaki disease is an acute febrile illness of infants and young children with arteritis of large to medium vessels; its danger is coronary artery aneurysms. Thromboangiitis obliterans (Buerger disease) is a segmental thrombosing inflammation of arteries and veins of the limbs in heavy smokers. ## Structure - PAN: segmental transmural inflammation with neutrophils, eosinophils and mononuclear cells; fibrinoid necrosis; thrombosis; healed lesions are fibrotic with nodular thickening. - Kawasaki: dense transmural inflammation of coronary arteries, less fibrinoid necrosis than PAN; healing leaves intimal thickening or aneurysms. - Buerger: sharply segmental acute and chronic inflammation of arteries, veins and nearby nerves; occlusive thrombus containing microabscesses with granulomatous rims. ## Three medium-vessel vasculitides compared | Disease | Who | Lesion | Main danger | | --- | --- | --- | --- | | [Polyarteritis nodosa](https://durgical.com/en/conditions/polyarteritis-nodosa/) | Young to middle-aged adults; hepatitis B in some | Segmental fibrinoid necrosis, lesions of different ages, microaneurysms | Renal and mesenteric infarcts, hypertension, mononeuritis multiplex | | [Kawasaki disease](https://durgical.com/en/conditions/kawasaki-disease/) | Children under 5 | Transmural arteritis of coronary arteries | Coronary aneurysm, thrombosis, myocardial infarction | | [Thromboangiitis obliterans](https://durgical.com/en/conditions/thromboangiitis-obliterans/) | Young heavy smokers | Inflammatory thrombus with microabscesses in arteries and veins | Digital ischemia, ulcers and gangrene | ## Clinical notes - Untreated PAN is often fatal; immunosuppression (and antivirals when hepatitis B is the cause) changes the outcome. - Early treatment of Kawasaki disease with intravenous immunoglobulin greatly lowers the rate of coronary aneurysms; a Kawasaki-like multisystem inflammatory syndrome was seen in children after SARS-CoV-2 infection. ## Memory aid PAN pockmarks the belly's arteries but leaves the lungs alone; Kawasaki is the child with red lips and the risky coronaries; Buerger is the smoker who loses his toes. ## Test yourself Think of the answer, then tap the question to see it. ## Which organ is spared in classic polyarteritis nodosa? The lungs (pulmonary arteries are spared), and there is no glomerulonephritis. ## What is the main cardiac complication of Kawasaki disease? Coronary artery aneurysms, which can thrombose or rupture and cause myocardial infarction. ## What is the single most important step in thromboangiitis obliterans? Complete stopping of tobacco use; the disease is strongly tied to smoking. [Add to my cards (3)](https://durgical.app/estudiar/?add=/en/general-pathology/medium-vessel-vasculitis/) [More Pathology questions →](https://durgical.com/en/practice/?f=pathology) ## Elsewhere in DurgiPedia - [Type III hypersensitivity (immune complexes)](https://durgical.com/en/immunology/type-iii-hypersensitivity/) ## Connections ## Related 4 - [Vasculitis: classification and mechanisms](https://durgical.com/en/general-pathology/vasculitis-classification-and-mechanisms/) - [Vessel hyperreactivity: Raynaud phenomenon and coronary vasospasm](https://durgical.com/en/general-pathology/vessel-hyperreactivity-raynaud-phenomenon-and-coronary-vasospasm/) - [Patterns of necrosis: coagulative, liquefactive, caseous, fat, fibrinoid, gangrenous](https://durgical.com/en/general-pathology/patterns-of-necrosis-coagulative-liquefactive-caseous-fat-fibrinoid-gangrenous/) - [Tobacco: how smoking injures tissue](https://durgical.com/en/general-pathology/tobacco-how-smoking-injures-tissue/) ## Related conditions 5 - [Polyarteritis nodosa](https://durgical.com/en/conditions/polyarteritis-nodosa/) - [Kawasaki disease](https://durgical.com/en/conditions/kawasaki-disease/) - [Thromboangiitis obliterans (Buerger disease)](https://durgical.com/en/conditions/thromboangiitis-obliterans/) - [Raynaud phenomenon](https://durgical.com/en/conditions/raynaud-phenomenon/) - [Myocardial Infarction (Heart Attack)](https://durgical.com/en/conditions/myocardial-infarction/) ## Microorganisms 1 - [Hepatitis B virus](https://durgical.com/en/microbiology/hepatitis-b-virus/) [← All of general pathology](https://durgical.com/en/general-pathology/) Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given. Sources: [Polyarteritis nodosa: MedlinePlus Medical Encyclopedia](https://medlineplus.gov/ency/article/001438.htm) (MedlinePlus, US National Library of Medicine, 2025); [Kawasaki disease: MedlinePlus Medical Encyclopedia](https://medlineplus.gov/ency/article/000989.htm) (MedlinePlus, US National Library of Medicine, 2025); [Thromboangiitis obliterans: MedlinePlus Medical Encyclopedia](https://medlineplus.gov/ency/article/000172.htm) (MedlinePlus, US National Library of Medicine, 2025). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/general-pathology/medium-vessel-vasculitis/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/general-pathology/medium-vessel-vasculitis/