A male patient with a personal history of habitual occupational sun exposure (taxi driver) presented with an asymptomatic dermatosis on the back of the left hand that had appeared 7 years earlier and had since grown slowly and progressively (Fig. 1). He had undergone topical corticosteroid treatment, without improvement. Examination revealed multiple translucent yellow papules with red-violet areas that coalesced to form a poorly defined plaque. Dermoscopic evaluation with polarized light at 10× magnification showed a diffuse orange background with some milia cysts and violet–red areas (Fig. 2). Histology of an incisional biopsy revealed a deposit of homogeneous pale eosinophilic material, fissures in the dermal papillae, and a surrounding discrete inflammatory infiltrate consisting mainly of lymphocytes. Periodic acid-Schiff and Congo red immunostaining of this deposited material were positive and negative, respectively.

Figure 1

Figure 2