EDN1 and freckles: Moreover, the H score for the dermal expression of ET-1 in the lesional skin of Riehl’s melanosis (H score, mean ± SD = 139.92 ± 15.05) was increased compared to perilesional skin (H score, mean ± SD = 111.20 ± 7.76; p = 0.003) and healthy controls (H score, mean ± SD = 66.60 ± 10.86; p = 0.001).