Association of Henoch–Schönlein purpura and Graves' disease

Sir, We read with interest the article ‘Henoch–Schönlein purpura associated with propylthiouracil overdose’ by Lee et al. [1]. They reported the first case of a patient with Graves’ disease who developed Henoch–Schönlein purpura (HSP) after a propylthiouracil overdose. We wondered whether HSP would have occurred if she had maintained the prescribed dosage. Although a causal relationship between HSP and Graves’ disease or propylthiouracil use is unclear, we recently reported the case of a patient who developed Graves’ disease during ciclosporin treatment for severe HSP nephritis [2], and speculated that these two diseases might be related. In the past 10 years, we have experienced two additional cases of HSP associated with Graves’ disease.