A 50-year-old white woman presented with tan-brown spots on her neck, chest, axillae, and groin area that had gradually developed over a period of more than 10 months. The lesions were mostly asymptomatic but were occasionally itchy. The patient was otherwise healthy. Her mother had similar lesions, mostly restricted to the arms, and her grandfather had similar lesions over almost all of his body.
Physical examination revealed 2- to 5-mm brown macules, some of which were slightly hyperkeratotic, distributed symmetrically over the lateral aspect of the neck, axillae, chest, and inner area of the thighs (Figure 1 and
Li L, Nahm WK, Moskowitz P, Badiavas E, Danahy J. Brown Macules Symmetrically Distributed on the Neck, Axillae, and Thighs—Quiz Case. Arch Dermatol. 2003;139(5):657-662. doi:10.1001/archderm.139.5.657-a