What is the diagnosis and treatment for Polyarteritis (Polyarteritis) nodosa vasculitis?

From the Guidelines

PTU vasculitis is a rare but serious autoimmune complication of propylthiouracil therapy, and the recommended approach is immediate discontinuation of propylthiouracil and switching to an alternative anti-thyroid medication, with treatment typically involving corticosteroids and monitoring of complete blood counts, urinalysis, renal function tests, and ANCA levels.

Key Considerations

• PTU vasculitis can affect multiple organ systems, including skin, kidneys, lungs, and joints, with symptoms ranging from rash and joint pain to more severe manifestations like glomerulonephritis or pulmonary hemorrhage 1.
• The condition occurs because propylthiouracil can trigger the formation of ANCA antibodies, leading to inflammation of blood vessels.
• Early recognition and prompt discontinuation of PTU are essential for preventing permanent organ damage.

Treatment Approach

• Immediate discontinuation of propylthiouracil and switching to an alternative anti-thyroid medication such as methimazole (if not contraindicated) or considering definitive therapy like radioactive iodine or thyroidectomy.
• Treatment typically involves corticosteroids, with prednisone usually started at 1 mg/kg/day (approximately 60-80 mg daily for adults) and gradually tapered over 3-6 months based on clinical response 1.
• Severe cases may require additional immunosuppressive therapy such as cyclophosphamide, azathioprine, or rituximab.

Monitoring and Follow-up

• Patients should be monitored with complete blood counts, urinalysis, renal function tests, and ANCA (anti-neutrophil cytoplasmic antibody) levels.
• Regular follow-up is necessary to assess disease activity and adjust treatment accordingly.

Guidelines and Recommendations

• The American College of Rheumatology and the Vasculitis Foundation have developed guidelines for the management of large, medium, and small vessel vasculitis, which include recommendations for the diagnostic testing, treatment, and management of PAN as an exemplar of medium vessel vasculitis 1.
• The EULAR recommendations for the management of primary small and medium vessel vasculitis provide a framework for clinical practice, including the use of cyclophosphamide and glucocorticoids for remission induction and the importance of monitoring for drug toxicity and disease activity 1.

From the Research

Ptu Vasculitis

• Ptu vasculitis is a rare and serious condition that can occur in patients taking propylthiouracil (PTU) for hyperthyroidism 2, 3, 4, 5.
• The condition is characterized by the presence of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis, which can manifest with inflammatory ocular, constitutional, pulmonary, and/or renal manifestations 2.
• Patients with ptu vasculitis may present with a range of symptoms, including red eye, fevers, hemoptysis, and renal dysfunction 2, 5.
• The diagnosis of ptu vasculitis is based on laboratory evaluations, including high-titer perinuclear ANCA and elevated anti-myeloperoxidase antibodies, as well as clinical manifestations such as episcleritis, diffuse alveolar hemorrhage, and microhematuria 2.
• Treatment of ptu vasculitis typically involves prompt discontinuation of PTU, as well as immunosuppressive therapy with steroids and other agents, such as rituximab 2, 4, 5.
• Cross-reactivity between PTU and methimazole has been reported, and patients who develop vasculitis with one medication may be at risk of developing it with the other 3, 6.
• Plasmapheresis may be considered in severe cases of ptu vasculitis, particularly those with pulmonary hemorrhage or other life-threatening complications 4.