Pearl of the Day: Non-freezing Cold Injuries

Non-freezing Cold Injuries Trench Foot - direct injury to soft tissue sustained from prolonged cooling, accelerated by wet conditions - symptoms: tingling, numbness at affected extremity - signs: pale, mottled, anesthetic, pulseless, immobile foot w/o immediate change after rewarming - 2 - 3 days: perfusion can return to foot; formation of bullae, edema, increased hyperemia - weeks: anesthesia can persist, may be permanent - months - years: hyperhidrosis, cold sensitivity - severe forms: gangrene, tissue sloughing - management: supportive and keep foot clean and dryly bandaged; can consider vasodilator drugs, oral prostaglandins (can increase skin temperatures) - prophylaxis: good boot fit, keeping warm, changing out of wet socks

Chilblains or Pernio - mild inflammatory lesions of skin from long-term intermittent exposure to damp, nonfreezing ambient temperatures - most common areas: feet (toes), hands, ears, lower legs - risk factors: countries with cold or temperate, damp climate; young females with Raynaud's phenomenon, immunologic abnormalities - signs/symptoms: pruritus, tingling, numbness; localized edema, erythema, cyanosis; ulcerations, bullae - rewarming can result in tender blue nodules that persist for several days - management: supportive, rewarm skin, elevate extremity - some studies support use of nifedipine 20 mg PO q8h, pentoxifylline 400 mg PO q8h, limaprost 20 mcg PO q8h as prophylaxis and treatment - topical corticosteroids may be effective

Panniculitis - mild degrees of necrosis of subcutaneous fat tissue during prolonged exposure to temperatures above freezing - in children, may be on cheeks; on thighs and buttocks of females involved in equestrian activities - upon resolution, may result in cosmetic defects (e.g., uneven skin) - no effective treatment

Cold Urticaria - hypersensitivity to cold air or water that may lead to anaphylaxis (rare) - associated with increased affinity of IgE to mast cells and viral infections - diagnosis confirmed with cold water test - treatment: similar to urticarial lesions from other causes (e.g., antihistamines); can consider leukotriene receptor antagonists, topical capsaicin

Resources Tintinalli's Emergency Medicine, 8th Edition