Itchy rash, oozing sores, scaly skin? These are just a few of the many symptoms of skin disorders. There are more than 3,000 kinds of skin disorders. Some are temporary, easily treated, and just a nuisance. Others can persist lifelong and cause chronic symptoms, disability, and emotional distress. Some skin conditions -- such as melanoma -- can even be deadly.
What does the skin do? It's the largest organ of the body and made up of three layers (epidermis, dermis, and subcutaneous layer). The skin forms a protective barrier for the body and guards against moisture, debris, and UV rays from the sun. Cuts and open wounds on the skin may allow pathogenic organisms into the body, which can cause infection. The skin contains oil glands that secrete sebum, a substance that helps moisturize the skin. Skin houses sweat glands that help keep the body cool. Nerves in the skin relay information about pain, temperature, and other sensations to the brain. Blood vessels and hair follicles are also found in the skin.
Skin problems are some of the most common reasons people visit the primary care physician. Everyone at some point has suffered from a skin problem and 1 out of 3 people in the U.S. has a skin condition at any point in time. Some conditions arise directly from the skin (for example, dermatitis, ringworm, rosacea, and more). Other non-dermatologic conditions (for example, herpes simplex virus, human papilloma virus, and others) have symptoms that manifest on the skin.
One study calculated the burden of dermatologic and non-dermatologic skin problems in the U.S. The burden was determined by the direct costs of treating the disorders as well as the indirect costs (lost wages due to missed work, etc.), reduced quality of life, and other factors. Using these criteria, the most prevalent conditions that affected the skin were:
Symptoms of skin disorders
There are thousands of skin disorders that vary in their signs and symptoms. Common signs and symptoms may include:
- Blotchy rash
- Bumps without pain or itching
- Butterfly rash
- Dry skin
- Flesh-colored growths
- Itchy rash
- Light-colored, patchy rash
- Mole that has changed size, shape, or color
- Painful, red blisters
- Painful bumps
- Peeling skin
- Pus-filled lesions
- Red bumps
- Red, flushed skin
- Ring-like rash
- Scaly, dry rash
- Scaly, oily rash
- Skin ulcers
- Sudden rash
- White, scaly rash
- Yellowish skin
Causes of skin problems
Skin disorders have a variety of causes. Some skin symptoms are due to non-dermatologic disorders. Some causes of skin symptoms include:
- Allergens that are ingested or come into contact with the skin
- Illnesses that affect other parts of the body
- Infection due to bacteria, fungi, viruses, or parasites
- Immune system weakness or dysfunction
- External factors like sun, animal dander, insect bites, or plants
There are many types of skin disorders. Infants, children, pregnant women, elderly individuals, and those with certain medical conditions suffer from certain skin conditions more than others.
Skin disorders in infants and children
Infants and children experience many of the same skin disorders as adults, but at different rates. Diaper rash is common in infancy. Atopic dermatitis (eczema) affects about 10% to 20% of infants and children. Atopic dermatitis causes an itchy, scaly rash. The condition is on the rise in children. Nearly 100% of kids, between the ages of 12 and 17, experience acne. Other skin conditions common in infants and children include warts, ringworm, psoriasis, fungal nail and skin infections, and seborrheic dermatitis. Many children get rashes and hives.
To help prevent childhood skin disorders, use gentle, non-irritating products to keep skin clean and moisturized. Apply non-chemical sunscreen (zinc and titanium are preferred) with an SPF of at least 30 daily. Children and teens who suffer at least one blistering sunburn more than double their risk of developing melanoma later in life. Seek treatment if your infant or child develops a rash, hives, warts, or other condition. Early diagnosis and treatment can minimize discomfort and speed healing.
Skin problems in pregnancy
Fluctuating hormone levels in pregnancy can affect women's skin. Stretch marks, "pregnancy mask" (melasma), pruritic urticarial papules and plaques of pregnancy (PUPPP), prurigo, pemphigoid gestationis, and intrahepatic cholestasis of pregnancy (ICP), impetigo herpetiformis, and pruritic folliculitis are skin disorders that may occur in pregnancy. Many of these conditions will disappear after the pregnancy. Pre-existing skin conditions -- such as atopic dermatitis, psoriasis, and other conditions -- can either become better or worse during pregnancy.
Skin problems in the elderly
The skin undergoes many changes with aging, some of which increase the risk of skin disorders. Skin becomes thinner, less elastic, loses moisture, and tears more easily. Skin tears, ulcers, dry skin, eczema, shingles, and pruritus (itching) are more common in older people than in younger people. Wounds are also slower to heal. Immune dysfunction is more common in the elderly, leading to increased rates of autoimmune skin diseases such as benign mucous membrane pemphigoid, bullous pemphigoid, paraneoplastic pemphigoid, and pemphigus vulgaris.
Medical conditions and skin problems
Many non-dermatologic disorders affect the condition of the skin. A few disorders that may cause skin signs and symptoms include:
- Autoimmune disease: A butterfly rash across the face is a tell-tale sign of lupus. Lupus may also cause other rashes and mouth sores. Those with lupus tend to be very sun sensitive.
- Cancer: Sometimes, skin changes can be a sign of cancer. For example, breast cancer may cause puckering and discoloration of the skin of the breast. Other cancers, including bladder, colon, kidney, lung, ovarian, stomach, and uterine cancer, may spread to the skin.
- Diabetes: High blood sugar levels that occur in diabetes may lead to bacterial and fungal skin infections, slow wound healing, and skin ulcers. Diabetes compromises blood circulation to the skin and other organs.
- Inflammatory bowel disease: Immune system dysfunction that occurs with ulcerative colitis or Crohn's disease can cause skin rashes and eruptions.
- Kidney disease: Skin discoloration, nail abnormalities, fungal nail infections, and extremely dry skin may be features of kidney disease.
- Liver disease: Yellowing of the skin may indicate jaundice, which is a failure of the liver to adequately break down dead red blood cells. Intense skin itching, red palms, and easy bruising may also indicate liver trouble.
- Sex hormone imbalance: An overabundance of male hormones (androgens) may cause severe acne, balding, and increased facial hair.
- Thyroid disease: A long-standing underactive thyroid (hypothyroidism) may lead to thickened, yellow skin and an enlarged tongue. An overactive thyroid (hyperthyroidism) may lead to flushed, warm, moist skin.
Other factors that affect skin
The skin is susceptible to both internal and external factors. Diet and stress are two internal factors that affect skin health. A person who has food allergies may develop skin symptoms. The ingestion of food allergens can lead to hives, angioedema, or atopic dermatitis (eczema). Stress affects hormone levels in the body as well as immune function. Stress can either trigger skin conditions or make them worse. Psoriasis, seborrheic dermatitis, rosacea, and fever blisters are a few skin conditions that can be triggered or worsened by stress.
The sun and external factors can affect the skin. Contact dermatitis is a rash that develops when the skin comes into contact with an allergic substance. Fragrances, nickel, and latex are a few common causes of contact dermatitis. The sun helps the skin manufacture vitamin D, but excess sun can lead to wrinkles, sunburn, and skin cancer. Many people with lupus find that sun exposure exacerbates their condition.
Medically Reviewed by Charles Patrick Davis, MD, PhD on 7/18/2014