Cantharone (Seres Laboratories Inc, Santa Rosa, Calif) (active ingredient, cantharidin) is a potent vesicant used topically to treat verrucae vulgaris.1 We recently encountered a patient who developed acute cellulitis and/or lymphangitis soon after topical application of Cantharone for eradication of plantar verrucae in an otherwise normal right leg. Although the patient's acute inflammation subsided, the peripheral swelling of her leg persisted and ultimately was documented by lymphangioscintigraphy to represent distal lymphatic obliteration (refractory lymphedema).
Stazzone AM, Borgs P, Witte CL, Witte MH. Lymphangitis and Refractory Lymphedema After Treatment With Topical Cantharidin. Arch Dermatol. 1998;134(1):104-106. doi: