Cutaneous signs and symptoms |
(10-50%) Palpable purpura, subcutaneous nodules, papules, vesicles, blisters, necrotic-ulcerative lesions, livedo reticularis/racemosa; pyoderma gangrenous-like ulcers. Ulceration and gangrene of the fingers or penis are rarely observed. |
(40-50%) Subcutaneous nodules, purpura, livedo reticularis/racemosa, vesicles, aseptic pustules, hives, necrosis - ulcerative and maculopapular rash mimicking erythema multiforme with target lesions on the limbs, particularly on the palmar regions. |
(30-60%) Palpable purpura, livedo reticularis/racemosa, nodules, hives lesions, skin ulcers with necrosis, blisters, erythema elevatum diutinum-like plaques. The limbs are most commonly affected and the lesions usually appear in an early stage of MPA. No relationship between any type of skin rash and incidence of renal and/or pulmonary involvement has been demonstrated. |
Oral mucosa |
(10-60%) Non-specific erosive/ulcerative oral lesions; strawberry gingivitis. |
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Upper and lower airways |
(70-100%) Sinusitis with purulent or bloody discharge; ulceration of the nasal mucosa and palate; saddle nose deformity, perforation of the septum. |
The prodromal or allergic phase is characterized by the occurrence of asthma (in approximately 95% of cases). Nasal polyposis, allergic rhinosinusitis, epistaxis. |
Pulmonary involvement is frequent and can be observed in up to 90% of patients. The classic pulmonary manifestation is diffuse alveolar hemorrhage due to pulmonary capillaritis. |
Kidney and urogenital tract |
(40-100% of cases) Usually with a characteristic histopathology of pauci-immune focal necrotizing glomerulonephritis with crescents formation associated with extracapillary proliferation, which in turn can cause a wide range of clinical features, from urinary abnormalities to rapidly progressive renal failure. The severity of renal involvement remains the main prognostic factor for renal function, as well as for survival. Prostatitis, orchitis, epididymitis, ureteral stenosis. |
In 25% of patients the most typical condition is a pauci-immune glomerulonephritis with crescents formation. |
Renal involvement is present in almost 100% of patients and is characterized by rapidly progressive glomerulonephritis with a histological pattern of pauci-immune necrotizing glomerulonephritis with crescents formation. |
Gastrointestinal system |
Ulcerative lesions, intestinal perforation. |
Eosinophilic gastroenteritis. |
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Peripheral nervous system |
Multiplex mononeuritis, sensory-motor neuropathy. |
Peripheral neuropathy. |
Peripheral neuropathy. |
Ophthalmologic involvement |
Episcleritis, scleritis, corneal ulceration, retinal vasculitis, retro-orbital granulomatous pseudotumor, or dacryoadenitis. |
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Histopathological findings |
Leukocytoclastic vasculitis with fibrinoid necrosis and neutrophilic infiltration of small dermal vessels; granulomatous inflammation around the vessels; nonspecific perivascular lymphocytic infiltration. |
Leukocytoclastic vasculitis with fibrinoid necrosis and granulomatous inflammation involving venules; neutrophil-rich inflammatory infiltrate. Tissue eosinophilia. |
Leukocytoclastic vasculitis with fibrinoid necrosis and neutrophilic infiltration of small dermal vessels; nonspecific perivascular infiltrate. A lymphocytic infiltration can be observed; cutaneous nodules often indicate vasculitis involving vessels in the deep dermis or subcutaneous tissue. |
Deposits in direct immunofluorescence of the skin |
IgM and/or C3 deposits around small dermal vessels in almost 70% of cases. |
IgM and/or C3 deposits around small dermal vessels in over 50% of cases. |
Usually negative; eventually IgM and/or C3 deposits are observed around small vessels. |