Obesity causes problems all over the body, and the skin is no exception. From dark, velvety patches to red, itchy skin-fold infections, skin tags and even psoriasis, a long list of skin problems can result from being obese. Some are due to the strain of the added weight. Others may relate to skin moisture and chafing. Still others are linked to biological changes that occur with obesity, including several hormonal and chemical imbalances.
Stretch Marks, Corns and Callouses
Stretch marks look like parallel streaks or lines in the skin. At first, they may look like red and shiny stripes, but they eventually become more scarlike. Stretch marks commonly occur on the breasts, hips, thighs, buttocks, abdomen and sides. Rapid weight gain can cause stretch marks. They are thought to result from tension in the skin as fat deposits expand beneath it. And, as excess body weight is transferred to the feet when standing, the skin along the soles of the feet responds to the repeated pressure by forming protective corns and callouses.
Skin Tags and Dark Patches
Skin tags are noncancerous growths that often occur on the neck, armpits, groin, eyelids and underneath the breasts. Obese people tend to have more skin tags than others. They may also develop acanthosis nigricans -- velvety, darkened brown-to-black skin patches. The affected skin may be thickened and have an odor. Both skin tags and dark patches can occur in people who are not overweight, but they are more common in people who are obese.
Excess body fat leads to extra folds of skin. The combination of moisture, warmth and skin rubbing against skin leaves these areas more susceptible to bacterial and fungal infection. Redness, itching, oozing, crusting and pain can develop beneath the breasts, around the armpits, along the waist, under the buttocks, in the groin and around the genitals. Infected pimple-type lumps called abscesses can develop beneath the skin in the armpits and groin, causing pain, drainage and deep scarring. This condition, called hidradenitis suppurativa, occurs almost exclusively in people who are overweight. Obesity also increases the risk of cellulitis -- a skin infection that can become quite serious and spread quickly to other tissues.
Other Skin Conditions
Obesity has been linked to many other skin conditions, including psoriasis. With psoriasis, itchy, dry, red patches with silvery scales develop. These patches or plaques can be almost anywhere on the body, but they commonly develop in skin creases and on the scalp or near the hairline. Obesity has been associated with many other conditions that can affect the skin, such as hormonal imbalances leading to unexpected hair growth and circulatory problems causing swollen legs and brownish skin discoloration. In those who are bed-bound, sores or pressure ulcers may occur.
When to Seek Medical Care
Always see a doctor for diagnosis and appropriate treatment of your skin condition. Seek emergency medical care if you have a fever and a rash that’s red, swollen, tender and warm, or if it's expanding.