The role of IL‐8 in skin lesions of a patient with erythema elevatum diutinum.

Erythema elevatum diutinum (EED) is a rare chronic cutaneous leucocytoclastic vasculitis with diffuse fibrosis, and its pathomechanism remains unclear.1,2 The published literature reported that chemotaxis towards interleukin-8 (IL-8) of neutrophils increased in patients with EED.3 IL-8 is a known neutrophil chemotaxis factor; recently, it has been suggested to be associated with fibrotic ailments, and elevated IL-8 levels in serum and skin have been reported in systemic sclerosis.4,5 Damaged endothelial cells release various chemotactic factors, including IL-8, which recruit inflammatory cells to exacerbate tissue damage, leading to scarring.6 Therefore, IL-8 is assumed to be involved in vasculitis and fibrosis of EED. The serum IL-8 levels were higher in the case with severe systemic symptoms of vasculitis; however, our case showed elevated levels of 19.5 pg/mL despite only skin symptoms. From differences in the number and distribution of IL-8-positive cells between EED and other vasculitis, IL-8 might trigger vasculitis leading to fibrosis in EED. [Extracted from the article]