Verrucous lesions arising in lymphedema and diabetic neuropathy: Elephantiasis nostras verrucosa or verrucous skin lesions on the feet of patients with diabetic neuropathy?

Verrucous skin lesions on the feet in diabetic neuropathy (VSLDN) develop in areas with sensory loss in diabetic patients. Although various types of chronic stimulation, such as pressure or friction, are considered an important factor in the development of such lesions, the precise pathogenesis of VSLDN remains obscure, and there is currently no established treatment for this disease. Here, we present a case of VSLDN on the dorsum of the right foot. However, because lymphedema was also observed at the same site, this lesion could also be diagnosed as elephantiasis nostras verrucosa arising in diabetic neuropathy. The lesion was successfully treated with a combination of elastic stocking and mixed killed bacterial suspension and hydrocortisone ointment, which suggested that VSLDN might have been exacerbated by the pre-existing lymphedema. Because various types of chronic stimulation can trigger VSLDN, treatment plans should be devised on a case-by-case basis. Therefore, it is important to investigate the presence of factors that can induce or exacerbate chronic inflammatory stimulation, such as lymphedema in our case, in each patient with VSLDN.