Hydroxychloroquine-Induced Nonthrombocytopenic Purpura: A Case Series.

Hydroxychloroquine (HCQ) is a disease-modifying anti-rheumatic medication for the treatment of various autoimmune conditions. A rare side effect of HCQ is thrombotic thrombocytopenic purpura (TTP). We present two cases of patients who developed purpura that did not meet TTP criteria following treatment with HCQ. While the etiology of HCQ-associated TTP is poorly understood, we propose a spectrum of manifestations related to HCQ, ranging from benign purpura to TTP. As multiple factors contribute to the disease, we believe that HCQ may act as a "second hit" in patients with genetic susceptibility, which also influences the variability in the severity of disease manifestations. J Drugs Dermatol. 2024;23(5):e124.     doi:10.36849/JDD.7781e.