Immunoglobolin deposits in erythema nodosun leprosum (ENL)

Erythema Nodosum Leprosum (ENL) skin lesions observed by fluorescence microscopy were found to contain immune complexes. While biopsies taken twelve of the lesions contained such deposits in the perivascular cell infiltrate. However, immunoglobulin deposits were observed in the dermis of all 25 ENL lesions studied. On the basis of localization of these fluorescent deposits the 25 skin lesions were classified under groups I to III and were correlated with the onset of the reaction. Control biopsies taken from the lepromatous leprosy patients without ENL were uniformly negative for immunoglobulin deposits.