8 Skin Clues to Diabetes

Sometimes chronic illnesses come with symptoms we don’t expect. For example, diabetes can be accompanied by changes in the appearance or texture of your skin – and in some cases, these changes may be an early clue that the illness is developing. Knowing the most common skin changes that can signal diabetes may help you get the diagnosis or treatment that you need.

“Blood sugar levels can have a significant impact on the health and function of the skin,” says Dr Brendan Camp, a dermatologist. “Because the skin is a visible organ, it can sometimes provide clues that there are metabolic changes occurring elsewhere in the body.”

Read on to discover exactly how high blood sugar can affect your skin, plus the most common skin changes that accompany diabetes, who may experience them and when you should give your doctor a call.

How blood sugar levels impact skin health

There are a few different ways that chronically high blood sugar levels may contribute to skin changes and conditions. “Chronically elevated blood glucose can affect small blood vessels, circulation, nerves and the immune system, all of which play important roles in maintaining healthy skin and supporting wound healing,” Dr Camp explains. More specifically, persistently high blood sugar creates an inflammatory environment that damages blood vessels – an environment that makes infections more likely to occur, says Dr Shari Lipner, a dermatologist.

“Diabetes may also contribute to dehydration and changes in the skin barrier, which can make the skin more prone to dryness, itching and irritation,” says Dr Camp. He adds that, in some cases, high blood sugar and insulin resistance can impact collagen production, resulting in more specific dermatological issues.

Common skin changes that can signal diabetes

“Several skin changes can be associated with diabetes or insulin resistance, although none should automatically be assumed to mean that someone has diabetes,” Dr Camp says. Here are the ones dermatologists see most often.

Acanthosis nigricans

“Acanthosis nigricans typically appears as darker, thicker, velvety skin, commonly around the neck, armpits or groin,” explains Dr Camp. “It’s often associated with insulin resistance, because elevated insulin levels can stimulate growth and pigment-producing pathways within the skin.” According to the American Academy of Dermatology (AAD), acanthosis nigricans may be the first noticeable sign that you have prediabetes or diabetes.

Skin tags

When you have excess insulin in the body, it can cause skin cells to overgrow, resulting in skin tags, explains Dr Lipner. Per the AAD, these are most common on the eyelids, neck, armpits and groin.

Dry, itchy skin

“People with diabetes may also experience dry, itchy skin, which can be related to dehydration, impaired circulation and changes in the skin barrier,” explains Dr Camp.

Shin spots

Shin spots, also known as diabetic dermopathy, are faint, brown patches on the shins, Dr Lipner says. They’re related to the way that chronically high blood sugar affects the small blood vessels in the skin. Shin spots tend to feel scaly at first, per the AAD, and then may cause small dents in the skin. People with diabetes may also develop yellowish, reddish or purplish patches on the shins that grow and become waxy in the middle – this condition is known as necrobiosis lipoidica and may be a sign that you have diabetes.

Skin infections

“Skin infections, including bacterial and fungal infections, may occur more frequently because elevated blood sugar can impair aspects of the immune response and provide conditions that allow certain microorganisms to thrive,” Dr Camp explains. The AAD notes that oral and vaginal thrush are also common with diabetes.

Slow-healing cuts, sores, or ulcers

“Diabetes can affect both circulation and nerve function, making an injury harder to detect and more difficult for the body to repair,” says Dr Camp. The result can be slow-healing injuries, particularly on the feet.

Yellowish bumps around the eyes

Technically called xanthelasma, these bumps may be a sign that your diabetes is poorly controlled, per the AAD. They can be caused by high levels of fat in your blood.

Eruptive xanthomatosis

Another sign that your diabetes isn’t well controlled and the levels of fat in your blood are too high, this condition is characterised by an outbreak of small, tender, itchy bumps, according to the AAD. Once diabetes is under control, the bumps tend to go away on their own.

Does everyone with diabetes have skin-related symptoms?

No, not everyone. “Only about a third of patients with diabetes develop specific skin findings,” says Dr Lipner. “So while their presence would give higher suspicion of diabetes, not having them doesn’t rule diabetes out, especially in people diagnosed early or with well-controlled disease.” Likewise, Dr Camp adds that many of the skin changes associated with diabetes can also have other causes unrelated to changes in blood sugar, so experiencing one or more doesn’t automatically point to the condition.

When do skin changes happen with diabetes?

It depends on the skin change. “Some changes associated with insulin resistance, such as acanthosis nigricans, can develop before a person has been formally diagnosed with type 2 diabetes and may serve as an early clue that further evaluation is warranted,” explains Dr Camp. “Other problems, such as recurrent infections, poor wound healing, diabetic dermopathy or foot ulcers, may be more likely to occur after diabetes has been present for some time, particularly when blood sugar isn’t well controlled or vascular and nerve complications have developed.”

Skin symptoms can also come and go, notes Dr Lipner, especially if you’re struggling to stabilise your blood sugar levels consistently. “Skin changes due to longer-term vessel and collagen damage, such as shin spots, may persist even after sugars are well managed,” she adds.

When to call your doctor

Any new, unexplained and concerning changes to your skin are worth a call to your doctor. In the context of diabetes specifically, Dr Camp says to look out for slow-healing wounds on the feet or lower legs, signs of infection like redness, warmth or swelling, and any new areas of thick, velvety or darkened skin. “Ultimately, dermatological changes can provide useful information, but a doctor can determine whether they’re related to diabetes or another skin or medical condition and recommend the appropriate evaluation and treatment,” says Dr Camp.