Final answer:
The test for a definitive diagnosis of polyarteritis nodosa is a biopsy of an affected organ, and treatment involves the use of immunosuppressive medications.
Step-by-step explanation:
The test for a definitive diagnosis of polyarteritis nodosa is a biopsy of an affected organ, such as the kidney or muscle. This can provide direct evidence of the characteristic necrotizing arteritis. Additionally, blood tests can be done to measure levels of inflammatory markers, such as C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR), which may be elevated in polyarteritis nodosa.
Treatment for polyarteritis nodosa involves the use of immunosuppressive medications, such as corticosteroids (e.g., prednisone) and other drugs like cyclophosphamide or methotrexate. These medications help to reduce inflammation, control the autoimmune response, and prevent further damage to organs.