Polar thigh
Background
A rash like injury characteristic of extended time in polar environments.
Clinical Features
Erythematous and often urticarial in appearance. Frequently seen on the anterior thigh, this injury can also appear on the medial and posterior thigh. Polar thigh can be seen in both genders. Although generally only seen in polar environments, polar thigh is actually thought to be a form of mechanical abrasion combined with air temperature fluctuations and variations in pockets of air trapped beneath clothing layers. This is frequently seen in skiers in Arctic environments due to : the frequent hip extension which stretches clothing overing the thigh, necessity of wearing multiple layers of clothes, and copious amounts of heat locally produced by such exercise. This theory is further supported by the fact that this injury is not seen in the upper arms which are subject to the same or similar wind, temperature, and clothing layers.
Differential Diagnosis
- Frostbite
- Allergic skin reaction
- Infection (Fungal/Bacterial/Viral)
Management
A topical corticosteroid (e.g, betamethasone valerate 0.025% or 0.05%) cream improves non-ulcerated rashes but should not be applied to polar thigh which has begun to ulcerate. If ulceration is present, apply a corticosteroid bandage or Granuflex. Proceed with general wound care. No antibiotics are necessary. If ulceration is severe, transfer to plastic surgery or burn unit might be necessary.
Disposition
If behavioral modifications are not taken, existing polar thigh can progress to frank ulceration.
Prevention
Polar thigh can be prevented by the use of long silk shorts or undergarments which prevent mechanical abrasion and improve temperature regulation or though the use of an emollient or aloe vera.
See Also
Frostbite
References
Rhodes, M & Sorenson, HC. Polar Medicine. In: Auerbach, PS,Auerbach's Wilderness Medicine. 7th ed. Elsevier; 2017.
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