In response to the spring sun distinct inflamed reddened skin develops on the ears, nose, cheeks, fingers, backs of the hands, and the lower arms, on which blisters with serous or hemorrhagic content develop. These dry out with the formation of a blackish scab. After shedding of the scab, depressed, varioliform, often hypopigmented scars remain. In addition, hyper- and hypopigmentation are present together, resulting in a polymorphous skin presentation. [from
HPO]