Here's a not-atypical case that might find its way to a doctor's office and then a dermatology clinic:
A middle-aged individual started noticing redness and itching at the tips of her toes about three months before going to the doctor. The itching progressed to soreness, and about a month before the dermatologist sees her the soreness was followed by red sores. The sores are redder and "sore-er" when her feet are exposed to cold, and when she goes outside.
This patient has never had similar symptoms in the past. She doesn't have any other symptoms of infection, such as joint paint, "tunneling" of the infection under the skin, or fever. She does not smoke.
This patient could also have been a man who had similar symptoms, of course.
The first thing that the doctor's assistant or nurse does it to get vital signs, pulse, blood pressure, temperature, O2 saturation, and breaths per minute. Let's say all of these are normal, and there aren't any signs of disease elsewhere in the body. Next the doctor feels for pulses at the axillary, brachial, radial, femoral, popliteal, dorsalis pedis, and posterior tibial regions, making sure there is normal circulation all the way down to the toes. There is. Then the doctor makes sure neuropathy isn't the problem. She will poke the foot and the toes with something that looks like a blunt needle, but not hard enough to break the skin. Let's say that there are normal responses to that test, too.
Finally, the doctor looks at the sores themselves. The doctor looks at the color. Are they red or "purpuric," more purple than red. Then the doctor touches them to see if they blanch, if they turn white, when exposed to pressure. Is there any redness around the sores? If there is, is sharply demarcated or poorly defined?
The doctor will probably order blood work to make sure the problem isn't due to blood clots. This information will come from tests of prothrombin time and partial thromboplastin time. The doctor will rule out systemic inflammation with erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). The doctor may test for a variety of autoimmune diseases and take a punch biopsy of the skin of the toes.
When all of this information is in, however, the key diagnostic information may come from the fact that whatever this condition is, it is worse when the feet were cold. If every other potential diagnosis is rule out, then the problem may be chilblains.
Chilblains, which are also known as pernio (the condition known as perniosis), can be "erythematous" (red) to "purpuric" (purple). They can cause itch that is followed by pain. If they recur in the same location time and time again, after cold exposure, they can form ulcers. Chilblains can from on the toes or the fingers. There is a related condition called panniculitis that can occur elsewhere on the body, especially the thighs. There is a condition called equestrian cold panniculitis that most commonly occurs in young women who ride horses in winter.
The reason that the doctor will usually do a complete workup when a patient comes in with what appear to be chilblains is that there are "secondary" chilblains that appear in lupus, leukemia, and after exposure to certain drugs, including the relatively common medication Lamisil (terbinafine) and the arthritis drug Remicade (infliximab). Secondary chilblains are more common in women than in men, and will persist into hot weather.
It's not difficult to distinguish chilblains from Raynaud's disease. Chilblains will last for days. Raynaud's lesions will last for hours. The main thing you can do to prevent chilblains is to keep your body's core warm. The problem is triggered by the movement of blood from your fingers and toes to the core of your body to maintain core temperature. It also helps to avoid caffeine and nicotine, which slow down the return of blood from your core to your extremities. There are medications (nifedipine) that may also help. See your doctor if you have chilblains when it isn't chilly, or make sure your doctor knows about them so you can be tested for the more serious diseases that may cause them.
Still have something to ask?
Get help from other members!