Histopathological changes showed slight hyperkeratosis of epidermis, marked thinning of stratum spinosum, hyperpigmentation of basal layer and many melanophages in the upper dermis.

• 皮损组织病理检查示:表皮轻度角化,棘层明显变薄,基底层色素增加,真皮上部有较多噬黑素细胞。