musculoskeletal and connective tissue disorders
Microscopic Polyangiitis (MPA)
Symptoms and Signs of MPA
Usually, a prodromal illness with systemic symptoms of fever, weight loss, myalgia, and arthralgia occurs. Other symptoms depend on which organs and systems are affected: Renal:The kidneys are affected in up to 90% of patients. Hematuria, proteinuria (sometimes>3 g/24 hours), and red blood cell casts are present. Without prompt diagnosis and treatment, renal failure may follow rapidly. Cutaneous:About one third of patients have a purpuric rash at the time of the diagnosis. Nail bed infarcts and splinter hemorrhages may occur; digital ischemia occurs rarely. If the lungs are affected, Diffuse Alveolar Hemorrhage may occur and may be followed by pulmonary fibrosis. Rapid-onset dyspnea and anemia, with or without hemoptysis and bilateral patchy infiltrates (seen on chest x-ray), may be due to alveolar hemorrhage, a medical emergency that requires immediate treatment. Some patients with MPA may initially present with interstitial lung disease. Mild symptoms of rhinitis, epistaxis, and sinusitis may occur; however, if the upper respiratory tract is severely affected, the cause is more likely to be granulomatosis with polyangiitis. Gastrointestinal (GI):GI symptoms include abdominal pain, nausea, vomiting, diarrhea, and bloody stools. If the nervous system is affected, Multiple Mononeuropathy (mononeuritis multiplex) that affects peripheral or cranial nerves usually occurs. Rarely, cerebral hemorrhage, infarction, seizures, or headache results from cerebral vasculitis. Cardiac:Rarely, the heart is affected. If the eyes are affected, Episcleritis usually results. 