Ice-pack dermatosis: a cold-induced dermatitis with similarities to cold panniculitis and perniosis that histopathologically resembles lupus.

IMPORTANCE Cold panniculitis is a self-limited condition, manifesting as erythematous plaques or nodules after cold exposure, that typically affects infants and children. Recently, a variant involving the lateral thighs of equestrians has been described. Since the original report of this variant, some confusion has arisen in the literature in which the terms equestrian cold panniculitis and equestrian perniosis are both used. Outside of this presentation, cold panniculitis in adults is exceedingly rare. OBSERVATIONS We describe 2 adult patients using ice-pack therapy for chronic back pain who developed erythematous, purpuric plaques at the site of ice-pack application. Histopathologic findings from both patients were similar and showed overlapping features of perniosis and cold panniculitis that closely resembled the pattern seen in cutaneous lupus erythematosus. CONCLUSIONS AND RELEVANCE Ice-pack dermatosis is an uncommon cold-induced process that occurs in adults using long-term ice-pack therapy. The clinical manifestations include erythematous to purpuric plaques with a livedolike appearance and superficial ulceration. The histopathologic features resemble those seen in cutaneous lupus erythematosus with a superficial and deep perivascular and periadnexal dermatitis with increased dermal mucin and a superficial lobular panniculitis.