The following symptoms and complaints may indicate microscopic polyangiitis (MPA):
- Renal involvement (70%) – glomerulonephritis (inflammation of the glomeruli (renal corpuscles) of the kidneys) of varying severity (rapid progressive glomerulonephritis (RPGN), focal segmental sclerosing glomerulonephritis (FSSGN)); leads to renal hypertension (high blood pressure caused by kidney disease), possibly with headache and development of renal insufficiency (kidney weakness)
- Skin involvement (40%) – subcutaneous nodules, palpable purpura (small-spotted capillary bleeding in the skin, subcutaneous tissue (subcutis) or mucous membranes (skin hemorrhage)), possibly necrosis; the lower extremities are often affected.
- Pulmonary involvement – pulmonary vasculitis (vascular inflammation), possibly with diffuse alveolar hemorrhage (bleeding) with blood in the sputum (sputum).
Other symptoms
- Episcleritis (inflammation of the episclera (highly perfused, loose layer of connective tissue separating the sclera (sclera) from the tunica conjunctiva (conjunctiva) at the anterior margin of the eye)).
- Myalgias (muscle pain) and arthralgias (joint pain).
- Polyneuritis (inflammation of the nerves)
- Sinusitis (sinusitis)