Case report: Propylthiouracil-induced serious side effect: Perinuclear antineutrophil cytoplasmic antibody-associated vasculitis or IgA vasculitis?

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a rare disease characterized by the inflammation and destruction of small blood vessels and circulating ANCAs. Drugs such as antithyroid drugs (ATDs), especially propylthiouracil (PTU), have been used for the production of ANCAs and cause the development of drug-induced AAV. The pathogenesis of this disease is unclear but could be related to the physiological processes affecting the degradation of neutrophil extracellular traps (NETs). At present, PTU is widely used in patients with Graves' disease (GD) who are preparing for pregnancy and whose condition has not been controlled. Once drug-induced AAV has occurred with important organ damage, considering NETs have a significant role in the immune system, whether the cessation of drugs could stop the progression of organ damage is unclear, and a consensus regarding standard treatment has not been established.