Skin problems are a common complication of diabetes; both type 1 and type 2.
According to research, as many as a third of people with diabetes will develop a skin disorder related to the disease at some point. Many of these, like certain rashes and blisters, can be in direct relation to diabetes or allergic reactions to insulin or diabetes medications.
Others, including some fungal infections and dry, itchy skin, can be common to otherwise healthy people but can affect those with diabetes more frequently.
Certain dermatological problems are among the first signs of diabetes (as well as other unrelated diseases and conditions, for that matter), so it’s important to see a dermatologist if you notice any unusual or unexplained changes in your skin. Early diagnosis and treatment are key to dealing with skin conditions caused by diabetes in order to ward off serious consequences and complications.
How Diabetes Affects Skin
Diabetes can have an impact on the health of the skin in multiple ways. High blood glucose levels (hyperglycemia) are behind most of the skin problems caused by diabetes. Too much sugar in the blood prompts the body to pull fluid from cells in order to produce enough urine to remove the sugar, which in turn makes skin dry (xerosis).
Dry, red, and irritated skin also can result from damage to nerves (diabetic neuropathy), particularly nerves in the legs and feet. Damaged nerves may not get the message to perspire, and perspiration helps to keep skin moist and soft.
In turn, when the skin is overly dry, it can crack and peel. What’s more, dry skin is itchy skin. Scratching can create small openings in the skin. These openings provide easy access for infectious organisms to get under the skin, where excess sugar in the blood provides a fertile breeding ground for them to proliferate.
Beyond dryness and infections are an array of other skin problems associated with diabetes.
This condition is characterized by patches of skin around the neck that are darker than a person’s normal skin color. These areas also can appear in the armpits and groin, and sometimes on the knees, elbows, and hands. The skin also may be thicker and take on a velvety texture.
Why it happens: Acanthosis nigricans is a sign of insulin resistance and so is sometimes the first sign of prediabetes or type 2 diabetes. It’s especially common in people who have obesity.
What to do: To make skin patches less noticeable they can be covered with make-up, but in the long run, weight loss is the most effective form of treatment.
Allergic Reactions to Medications
Nearly any diabetes medication—including insulin—can trigger an allergic reaction that brings on symptoms that affect the skin, such as itching, swelling, rash, or redness.
Why it happens: Allergic reactions to medications occur because a person has a pre-existing sensitivity to either the drug itself or to an inactive ingredient in the drug, such as a preservative. Some people who use injectable medications experience skin reactions that are limited to the area where the needle was inserted.
What to do: Call your doctor if you have an allergic reaction to a diabetes medication. He or she may instruct you to take an over-the-counter medication to relieve itching in the short term, and then will discuss trying a different drug to treat your diabetes.
Bullosis Diabeticorum (Diabetic Blisters)
Painless, sometimes large, blisters that arise spontaneously on the tops and sides of the lower legs and feet, and sometimes on the hands or the forearms
Why it happens: It isn’t known what causes diabetic blisters to appear. However, they are more common in people who develop diabetic neuropathy, a group of nerve disorders that affects people with both type 1 and type 2 diabetes.
What to do: Most blisters heal in three weeks or so, without leaving scars, according to the American Diabetes Association (ADA). The only treatment is to bring blood sugar levels under control.
Scaly light brown or red patches that often appear on the fronts of the legs. Usually oval or round in shape, they resemble age spots and sometimes are called skin spots. They do not hurt or itch.
Why it happens: Changes in small blood vessels reduce blood supply to the skin.
What to do: This harmless, painless condition does not need treatment.
It starts with tight, waxy skin on the backs of the hands and stiffness of the fingers; some people may feel as if they have pebbles in their fingertips. As the condition progresses, skin can become hard, thick, and swollen, spreading throughout the body starting with the upper back, shoulders, neck, chest, and even face. Rarely the skin of the knees, ankles, or elbows thickens and takes on the texture of orange peel, making it hard to move the affected joints.
Why it happens: Digital sclerosis is most common in people with type 1 diabetes who have other complications or whose disease is difficult to treat.
What to do: Getting better control of diabetes can help. Meanwhile, physical therapy can bring more ease of movement to stiff joints.
Disseminated Granuloma Annulare
Rash characterized by reddish or skin-colored arcs or ring shapes on the fingers and ears, and sometimes on the front of the torso. The relationship between granuloma annulare and diabetes is somewhat controversial, but a 2017 study did find that subjects with the rash had elevated blood sugar levels.
Why it happens: There are no known causes of granuloma annulare, even when not associated with diabetes.
What to do: Most rashes caused by granuloma annulare disappear within a few months, although sometimes the bumps stick around for up to two years. There’s no medical reason to treat it, but if it’s bothersome options include prescription-strength corticosteroid creams, ointments, or injections; applying liquid nitrogen to freeze off the lesions; laser therapy; certain oral medications.
Itchy, waxy, yellow bumps on the skin surrounded by red halos. They are most often found on the face and buttocks, and can also appear on the extremities. Especially prevalent among young men with type 1 diabetes.
Why it happens: High levels of cholesterol and fat in the blood result when blood sugar levels aren’t well controlled.
What to do: Treatment involves bringing blood fats under control; lipid-lowering drugs may also be needed.
Necrobiosis Lipoidica Diabeticorum (NLD)
Symptoms: Rash on the lower legs characterized by slightly raised shiny red-brown patches with yellowish centers that may develop into open, slow-healing sores. More common in women. Usually goes through stages of activity and inactivity. Sometimes requires a biopsy to diagnose.
Why it happens: Changes in fat and collagen beneath the skin’s surface.
What to do: Although difficult to treat, NLD sometimes responds to topical cortisone creams or cortisone injections. Ultraviolet light treatment has been found to control this condition when it is flaring. A baby aspirin each day, and other medications that thin the blood, such as Trental (pentoxifylline), may help.
Rare condition that involves thickening of the skin on the upper back and neck.
Why it happens: The cause is unknown but scleredema diabeticorum does seem to occur more often in people who are obese.
What to do: Moisturizers may help, but treatment entails bringing blood sugar levels within control.
About 25 percent of people with skin tags have diabetes. These small, polyp-like pieces of flesh occur most often on the neck, eyelids, and armpits.
Why it happens: There appears to be a link between skin tags and insulin resistance as well as to abnormal blood fats.
What to do: Although there’s no reason to treat them, if they’re bothersome or unsightly they can easily be removed.