Propylthiouracil-induced ANCA-negative cutaneous small vessel vasculitis

Abstract

Propylthiouracil (PTU) is a commonly used medication for the treatment of hyperthyroidism. PTU is known to cause different adverse reactions including autoimmune syndromes. PTU-induced autoimmune syndromes can be classified into drug-induced lupus or drug-induced vasculitis. Differential diagnoses could be very challenging. PTU-induced vasculitis is more common than PTU-induced lupus, and has a higher risk of morbidity and mortality. Usually it is limited to the skin in a form of cutaneous leukocytoclastic vasculitis, but may also affect organs including kidneys and lungs. Discontinuation of PTU should be a first step in the treatment and could lead to complete resolution of symptoms. Typically, lesions resolve spontaneously within 2–4 weeks, but chronic or recurrent disease may occur in up to 10% of patients. In cases without improvement after drug discontinuation, cases refractory to glucocorticosteroids, with necrotizing skin lesions or extracutaneous organ involvement referral to rheumatologist for more aggressive immunosuppressive treatment is indicated. Optimal duration of immunosuppressive therapy is unknown, but it is reasonable to gradually taper mediations and monitor clinical response. Frequent monitoring for side effects is mandatory for patients on PTU therapy. Treatment should be stopped immediately, if patient develops any of autoimmune syndromes. An accurate and prompt diagnosis is essential, because it determines further management. We report a rare case of antineutrophil cytoplasm antibody-negative cutaneous small vessel vasculitis as a result of longstanding exposure to PTU.

Rash and cholestatic liver injury caused by methimazole in a woman with Turner syndrome and Graves’s disease: a case report and literature review

“…In another study, PTU successfully controlled hyperthyroidism in a patient with TS and GD, but the patient ultimately had to be treated with 131 I therapy due to vasculitis [ 25 ], and the researchers believe that TS patients are at risk of developing autoimmune diseases, which may increase the incidence of vasculitis and other autoimmune diseases during treatment with antithyroid drugs. PTU can cause not only clinically obvious, severe or even fatal liver injury but also induce skin-limited vasculitis or necrotizing skin injury [ 26 ]. TS can lead to liver injury characterized by asymptomatic elevation of ALT, AST, and GGT.…”

Bad bites? A case report of rapidly progressive painful necrotic lower limb lesions from propylthiouracil‐associated vasculitis

“…It is difficult to distinguish clinically and serologically. PTU‐associated vasculitis is thought to be more common …”

Vasculitis associated with the use of an intrauterine device: A case report

“…The non-infectious causes of vasculitis include ocular disorders and can be drug-induced, i.e., vasculitis associated with a systemic inflammatory disease and vasculitis associated with malignancies (9)(10)(11). Drug-associated vasculitis is frequently difficult to identify, because many patients follow treatments with more than one drug and the route of administration varies (12)(13)(14)(15). In addition, patients may forget, neglect or hide drug intake.…”