“…However, its precise pathogenesis remains unknown, some authors having considered it a cutaneous manifestation of diabetic microangiopathy and others an immune complex vasculitis. 1,2 In addition, some investigators have considered collagen abnormalities to be the initiating event; lysyl oxidase, which produces collagen cross-linking by the oxidation of lysine and hydroxylysine has been found to be significantly elevated in both NL and diabetes in one study, ,3 whereas in another, the overhydration of collagen was observed in diabetic skin. 4 Furthermore, recent studies have also successfully shown that glycation and oxidation -the age-dependent chemical modification of collagen -are accelerated in diabetes; 5,6 glycation (or nonenzymatic glycosylation) is a post-translational modification of protein, which results from chemical reactions between glucose and certain amino groups in proteins, 7 this reaction then forming fructoselysine and fructosehydroxylysine in collagen, 7 after which further oxidation results in the formation of glycoxidation products such as N(carboxymethyl)lysine and N(carboxymethyl)hydroxylysine.…”