Alerts and Notices
SynopsisEquestrian perniosis is a rare variant of perniosis that usually affects the thighs and buttocks of (most often female) horseback riders. It may affect individuals in other recreational scenarios involving cold exposure and underinsulated, tight-fitting clothing, such as motorcycle riders or outdoor enthusiasts. Smoking, age of less than 35 years, and longer duration of riding have been correlated with development of the condition. The presence of cold agglutinins has been reported in a minority of cases.
Equestrian perniosis is localized to the lateral thighs. Rarely, buttock involvement has been reported. Red or violaceous plaques or nodules appear after cold exposure, sometimes as soon as 24-48 hours thereafter. Lesions may be accompanied by mild to moderate pruritus, burning, or tenderness, or they may be asymptomatic. Most cases are self-limited, although more severe cases can lead to blistering and ulceration. Hyperpigmentation and scarring may occur upon resolution.
T69.1XXA – Chilblains, initial encounter
37869000 – Chilblains
Differential Diagnosis & Pitfalls
- Cold panniculitis
- Cold urticaria
- Antiphospholipid syndrome
- Early Coumadin necrosis
- Early calciphylaxis
- Lupus profundus
- Spider bite – typically unilateral
- Cellulitis – typically unilateral
- Ecthyma – typically unilateral