[Christmas article: Christmas-related exogenous palmar hyperpigmentation].

On a routine control for macular degeneration, a 90-year-old man presented with hyperpigmentation of the skin on both palms and bilateral thumbnail discolouration. He was otherwise asymptomatic. He had been shelling walnuts to store in his freezer for use as Christmas cake decorations. Shortly after, he noticed the cutaneous colour change in both palms. The condition resolved spontaneously over a period of about three weeks. Outbreaks of walnut shell-related hyperpigmentation tend to occur during the cake decorating season, especially at Christmas time, and often present with so-called "cake decorators' palms".