Vasculonecrotic reactions in leprosy

Multibacillary, lepromatous or borderline leprosy patients may present two types of vasculonecrotic reactions: Lucio phenomenon and that associated with erythema nodosum leprosum. Despite they can be distinguished through clinical and histological characteristics; both are often used as synonyms. It is said that leprosy reaction should be properly classified for therapeutic reasons, since it is well known that in Lucio phenomenon there is not a good response to thalidomide. The authors reported two cases of vasculonecrotic phenomena in lepromatous leprosy sharing clinical and histopathological characteristics of both reaction subtypes. The findings may indicate the spectral nature of the reaction phenomena in leprosy and emphasize the importance of the clinic-pathological correlation for proper classification. Our findings may contribute to the understanding of leprosy reactions pathogenesis, broaden the knowledge about their outcome with standard treatment, and provide the scientific background to design better therapeutic strategies for these complications.