• We describe four patients with panniculitis attributable to a combination of cold exposure and equestrian activities. All were young, healthy women who rode horses for at least two consecutive hours per day throughout the winter. Initially, several small, erythematous, pruritic papules appeared on the superior-lateral portions of one or both thighs. During one week, the lesions progressed to indurated, red-to-violaceous, tender plaques and nodules. Studies for cryofibrinogens and cryoglobulins were negative. The histologic picture was that of a panniculitis with prominent inflammation of veins most notable at the dermal-subcutaneous fat junction. Cold panniculitis is not limited to infancy and childhood. The distribution of lesions in our patients may have been caused, in part, by the use of tightfitting, uninsulated riding pants. Such attire may have slowed blood flow through the skin, thereby further reducing tissue temperature. (Arch Dermatol 116:1025-1027, 1980)