Reply to: "Commentary on 'A new drug with a nasty bite: A case of krokodil-induced skin necrosis in an intravenous drug user'".

To the Editor: I thank the authors for their reply to our article. Levamisole, an adulterant most commonly found in cocaine, can be associated with skin vasculitis resulting in ulcerating lesions.1, 2 The most common cutaneous findings are characteristic purpuric lesions, including retiform purpura or palpable purpura, which often occur in conjunction with leukocytoclastic vasculitis. These lesions favor acral surfaces such as the helical rim or fingertips and are often antineutrophil cytoplasmic antibody positive.1, 2 On the contrary, large ulcerations on the forearms would be an unusual presentation for levamisole toxicity, especially in the absence of more classic findings as noted above. In cases such as these, physical examination is important, and cutaneous findings must be emphasized. The patient only had involvement where she directly injected the substance, another finding that is unusual for levamisole, which often affects areas distal to areas of injection owing to systemic activity without antineutrophil cytoplasmic antibody positivity. Finally, the patient voluntarily reported purchasing krokodil immediately before the ulcerations occurred. I caution against the author's sentiment of completely excluding patient history, especially when clinical findings support the history provided. We believe that doctors should continue to exercise vigilance and keep krokodil on their differential of possibilities in cases of large ulcerations in patients with a history of intravenous drug use.