Aetiology of small vessel vasculitis of the lungs (pulmonary capillaritis) in order of relative frequency1–3
| Isolated pauci-immune pulmonary capillaritis |
| Pulmonary allograft rejection |
| Systemic lupus erythematosus |
| Wegener's granulomatosis |
| Microscopic polyangiitis |
| Goodpasture's syndrome |
| Rheumatoid arthritis |
| Polymyositis |
| Primary antiphospholipid syndrome |
| Scleroderma |
| Idiopathic pauci-immune glomerulonephritis |
| Henoch-Schoenlein purpura |
| IgA nephropathy |
| Behcet's syndrome |
| Hypersensitivity vasculitis |
| Propylthiouracil |
| Diphenylhydantoin |
| Churg-Strauss syndrome |
| Essential cryoglobulinaemia |
| Acquired immune deficiency syndrome |
| Myasthenia gravis |
| Ulcerative colitis |
| Retinoic acid syndrome |
| Autologous bone marrow transplantation |