Diabetes Complications: More Than Skin Deep
About 16 million Americans have diabetes, an illness
in which the pancreas produces insufficient insulin (the hormone
responsible for the uptake of glucose by body tissues). About
90% have type 2 diabetes, which develops gradually after about
age 40. The remainder have type 1 diabetes, which usually occurs
much earlier. At some point during the course of their illness,
at least one third of sufferers are bothered by troublesome skin
Proper skin care and long-term control of blood
glucose levels may reduce the risk of some of these skin problems.
Without treatment, complications can arise, including open sores
(ulcers) and, in very severe cases, even gangrene or life-threatening
infection. Skin problems in a person with diabetes may indicate
the need for more aggressive diabetes management; in otherwise
healthy people, some skin abnormalities may signal a need for
an evaluation to determine if diabetes is present.
Risk of Infection
Anyone can develop a skin infection, but people
with diabetes are especially vulnerable. In one study of 457
patients, 20% of those with type 2 diabetes had a skin infection.
Such infections are generally either bacterial or fungal.
Bacterial infections are usually caused by one
or more of several staphylococcus, streptococcus, or pseudomonas
organisms. The infected area is typically hot, red, and itchy.
Common manifestations include styes (infections of the glands
of the eyelid), boils (infections of the hair follicles), carbuncles
(deep infections of the skin and the tissue underneath), and
infections around the nails.
A yeast known as Candida albicans is responsible
for most fungal infections. It usually causes an itchy, red,
moist rash surrounded by tiny pimples, usually in the warm, moist
folds of the skin. Candida albicans is also a frequent cause
of a vaginal infection characterized by a white, cheesy discharge
and marked itching. Fungi known as dermatophytes cause other
rashes, including "jock itch" and "athlete's foot."
Skin infections should be treated by a physician.
Without proper care, they may not heal or can spread throughout
the body. Good skin-care habits can also speed recovery and may
reduce the likelihood that an infection will occur in the first
place (see "Keeping Skin Healthy").
Other Skin Problems
Most noninfective diabetic skin disorders appear
in people who have had diabetes for many years. But skin changes
may also be the first manifestation of diabetes and often prompt
doctors to screen for diabetes. The two most common, diabetic
dermopathy (DD) and various types of skin thickening, are relatively
benign. Although both may cause permanent skin changes, they
are not painful.
Also called shin spots, DD is the most common skin
disorder seen in older people with diabetes. It is characterized
by round or oval reddish-brown spots on both shins. Spots sometimes
also appear on the forearms, the sides of the feet, and the front
of the lower thighs. Although the affected area may become permanently
discolored, there is no discomfort. DD spots can develop in nondiabetics,
but this is relatively rare.
The most common place for skin to thicken is on
the backs of the hands and fingers, especially over the knuckles.
Although there are no treatments for either condition, skin thickening
may subside over time.
A condition called acanthosis nigricans (AN) typically
strikes people with diabetes who are very obese. AN is characterized
by raised, velvety tan or brown spots on the sides of the neck,
armpits, and groin, and sometimes on the top of the hands, elbows,
and knees. Perspiration typically causes the lesions to itch.
Weight loss may prevent the development of new spots, and prescription
creams can help minimize discoloration.
Other skin disorders can be more troublesome. A
condition called necrobiosis lipoidica (NL) causes red, well-defined,
bite-like bumps or flat lesions (papules) on the legs. As they
develop, the lesions expand and flatten into saucer-like plaques,
and nearly one third ulcerate. About 80% of NL cases occur in
women. Although there is no cure, treatment with oral, injectable,
or topical medications can help limit ulceration, relieve discomfort,
and speed healing. Only 0.3% of diabetics have NL, but most people
with NL also have diabetes, elevated blood glucose levels, or
a family history of diabetes. Therefore, anyone with NL who has
not been diagnosed with diabetes should be screened for it. People
with NL and a negative screening test should be reevaluated yearly.
People with long-standing diabetes and diabetic
neuropathy (damage to nerves supplying the feet and hands) may
develop a disorder called bullosis diabeticorum (BD). It is characterized
by clear, fluid-filled blisters (bullae) that spontaneously arise
from apparently normal skin. The blisters usually appear on the
feet and toes but can also develop on the hands and fingers.
Although the blisters generally heal on their own, skin-care
measures (such as keeping affected areas clean and protected)
can help prevent secondary infection.
Keeping Skin Healthy
For most people, a little skin pampering is a pleasure.
For people with diabetes, it is an essential component of health
care. The following measures are wise for everyone, but they
are indispensable for those with diabetes:
blood glucose levels. Elevated blood glucose may increase
susceptibility to infection.
an oil-in-water skin moisturizer (such as Eucerin Original Lotion)
or a lighter water-in-oil product (such as Lubriderm or Alpha-Keri).
Except when using an antifungal cream, do not put creams between
the toes, where extra moisture may encourage fungal infection.
properly. Use warm water (which is less drying than
hot water) and mild, moisturizing bath products (such as Dove
off gently and thoroughly. Pat the skin dry, paying
special attention to folds in the skin and the areas between
the toes, but leave other skin surfaces slightly damp and seal
that moisture into the skin with moisturizing cream.
indoor humidity with a humidifier, especially during the winter,
when the air tends to be driest.
for your feet. Visually inspect the feet for irritation
and sores every evening when you remove your shoes.
cuts and scrapes promptly. Flush the injured area with
water and wash it with antibacterial soap (Mercurochrome, antiseptic,
alcohol, and iodine are too harsh). Check with your doctor
before using over-the-counter topical antibiotics.
when to see a doctor. Major cuts, burns, infections,
and skin problems that persist require professional care.
From The Johns
Hopkins Medical Letter: Health After 50, January 2000.