The correct answer is golfer’s vasculitis (choice “d”), which favors older patients who spend extended periods on their feet in hot weather.
Schamberg’s disease (choice “a”), a type of capillaritis, presents with nonblanchable, true purpura that are classically described and seen as having a peculiar brown color (which has been called cinnamon or cayenne pepper).
Those who experience a true contact dermatitis (choice “b”) almost invariably itch and would most likely present with vesiculation of the skin surface.
Leukocytoclastic vasculitis (LCV; choice “c”) presents as a nonblanchable purpuric condition that, on biopsy, demonstrates classic findings of red blood cell (RBC) extravasation from venules damaged by neutrophils.
“Golfer’s vasculitis” has been described in nongolfers who are older and who have spent considerable time on their feet in hot weather. Fair-goers, amusement park patrons, and hikers are just as likely to develop it, but it was first studied in golfers—and at first, it was thought to represent a sensitivity to chemical grass treatment.
However, the lack of symptoms and vesiculation (blistering) suggested otherwise, and biopsies of the affected skin confirmed gravity-related hyperemia with mild extravasation of RBCs. They also failed to show any signs of contact dermatitis. The sharply defined linear inferior border of the rash is clearly caused by the compressive effects of socks, which prevent the leakage of RBCs.
The other items in the differential were rightly considered—particularly LCV, which can be associated with conditions such as hypersensitivity reactions to medications or can be a presenting sign of lupus and rheumatoid arthritis, among several other possibilities. But the key differentiating finding was the highly blanchable nature of this patient’s condition, in marked contrast to the nonblanchable, purpuric nature of classic LCV.
Often enough, blanchability is partial, or at least questionable, and a punch biopsy is necessary to clarify the picture. When histologic signs of LCV are found, blood work is necessary to rule out similar damage to “end organs,” such as kidneys and liver, as well as to attempt to establish the causative trigger.