When A Patient Presents With A Painful Red Toe
Deep frostbite. In deep frostbite, the skin is numb and feels hard like wood. It looks pale or white. At this point, muscle and bone may be frozen. In more severe cases of frostbite, the skin can turn blue, gray or even black because of tissue injury. These changes sometimes do not happen until after the area warms up. Deep frostbite needs immediate medical attention. In severe cases, deep frostbite can lead to permanent injury, amputation and even death.
Risk factors for frostbite include the following:
• inadequate shelter
• inadequate or constrictive clothing
• wind chill factor
• high altitude
• prolonged exposure to cold
• prolonged exposure to moisture
• malnutrition and exhaustion
• previous cold injury (previous injury increases risk twofold)
• peripheral vascular disease, diabetes mellitus or thyroid disease
• improper behavioral response to cold ambient temperature
• blocked arteries, atherosclerosis or other problems that affect blood circulation
• exposure to drugs with vasoconstrictive effects such as beta-blockers, which decrease the blood flow to the skin
• a low percentage of body fat
• drinking alcohol, which increases the loss of body heat
• drinking caffeine, which increases dehydration
• using nicotine, which decreases blood flow to limbs
A Guide To The Differential Diagnosis
Erysipelas. This is an acute infection of skin and subcutaneous tissue caused by beta-hemolytic Streptococcus with spreading inflammation and swelling. The area is warm and the patient may have a temperature.
Raynaud’s disease. This is a vasospastic disorder of the small peripheral arteries. The most common form is idiopathic primary Raynaud’s disease and is found in young women. Secondary Raynaud’s disease may be due to other connective or soft tissue disorders such as rheumatoid arthritis, systemic lupus or scleroderma. Occasionally, secondary Raynaud’s disease may be due to peripheral vascular occlusive disease, neurogenic lesions or drug intoxications.
Contributing factors include cold exposure and nicotine. Raynaud’s disease is often seasonal and most active in the cold weather months.
Paronychia. This infection develops along the edge of the toenail.
Thrombosis obliterans. This is inflammatory thrombosis of small and medium-sized arteries and some superficial veins, causing arterial ischemia in distal extremities and superficial thrombophlebitis. Tobacco use is the primary risk factor.
Dry gangrene. Dry gangrene is the term used to describe the death of tissue caused by a lack of blood supply. It is most common in people with advanced blockages of the arteries (arteriosclerosis) resulting from diabetes.
Acute irritant contact dermatitis. This occurs when the skin comes in contact with a strong toxic chemical and causes a rash (sharp borders with vesicles or bullae). The rash occurs within minutes to hours after exposure and, in most cases, healing occurs soon after exposure ceases.
Bullous diabeticorum. This is a distinct, spontaneous, noninflammatory, blistering condition of acral skin unique to patients with diabetes. Blisters occur spontaneously and abruptly, often overnight and usually without known antecedent trauma. Lesions tend to be asymptomatic although patients have described mild discomfort or burning. Blisters heal spontaneously within two to six weeks of onset.
Pertinent Insights On Pathophysiology
With frostbite type injuries, two main reactions take place when tissues come into contact with very cold temperatures.