5 Most Common Skin Disorders

Almost everyone has known the horror of waking up to a glaring-red zit. Acne is the most common skin condition, but it's usually the least severe. Others can be equally embarrassing -- and some can even be life-threatening.

Because skin is the largest body organ, the effects of its disorders are as psychological as they are physical.

Acne, eczema, seborrheic dermatitis, skin cancer and psoriasis are the five most common skin disorders, says Dr. Macrene Alexiades-Armenakas, assistant clinical professor at Yale University School of Medicine.

Although these five appear at the top of most lists, there is a lot of disagreement among dermatologists about what their prevalence rates really are, Alexiades-Armenakas said.

1. Acne

Acne is a skin disorder that causes pimples when the passageway that connects the skin’s pores to the oil glands becomes clogged.

Acne, which appears most often on the face, neck, shoulders, chest and back, can come in many forms. Whiteheads and blackheads are the most commonly known; nodular and cystic acne are more severe because they form deep in the skin and can cause scars.

Eighty percent of Americans will have acne at some point in their lives, and 60 percent will continue to experience it into adulthood.

Factors like heredity can play a role in developing acne, but Alexiades-Armenakas said that hormones are the most important factor.

"In both men and women, the reason it peaks in the teenage years is because growth hormone is released at a very high frequency," Alexiades-Armenakas said. "Production really spikes and valleys in the course of a day, and this surging of the growth hormone is why acne is most severe in the teenage years."

2. Eczema

Eczema is a "grab-bag term," which Alexiades-Armenakas said comes from the Greek word for "boils over." There are three common forms of eczema:

— Atopic dermatitis is the most common and is seen most often in children. One to three percent of adults compared to 10 to 20 percent of children have this long-term genetic disease, which causes itchy rashes in the crux of the elbows and behind the knees.

— Allergic contact dermatitis begins to show in adulthood and is caused by environmental factors such as cosmetic agents, fragrances and the metals in jewelry.

— Nummular dermatitis looks like red and flaky coin-shaped patches of skin and is due to dry skin. This can be very itchy.

"In all cases, what you want to do is moisturize the skin, build up the skin barrier and avoid drying out the skin," Alexiades-Armenakas said. "And then, usually, we use corticosteroids for these conditions."

3. Seborrheic Dermatitis

Seborrheic dermatitis, which causes oily, waxy patches to develop on the scalp, is distinct from other forms of dermatitis.

It affects 5 percent of people, according to U.S. News and World Report. It can affect babies, typically in the first six months of their lives in the form of "cradle cap" -- a flakey, dandruff-like condition on the scalp. After the symptoms clear up, it rarely appears again until puberty.

4. Skin Cancer

Skin cancer is the most common type of cancer in the United States.

According to the American Academy of Dermatology, one million people are diagnosed with skin cancer annually, and 1 in 5 Americans will develop skin cancer in their lifetime.

Basal cell carcinoma and squamous cell carcinoma are the most common types of skin cancer. But 75 percent of skin cancer deaths are from melanoma, the third most common form.

Slideshow: The ABCDs of Skin Cancer

Alexiades-Armenakas said that sun damage is on a spectrum with skin cancer because excessive exposure to ultraviolet light is a leading cause and requires physicians to be well-versed in treating it early.

"More often than not, a patient will come in, and the lesions that bring them into the office and what their chief complaint is one of these two things: sun damage or hyper-pigmentation," Alexiades-Armenakas said.

Genetics play more of a role in basal cell and melanoma than in squamos cell, which is due to sun exposure.

5. Psoriasis

Psoriasis is a chronic and disfiguring genetic disease. It is a buildup of excess skin tissue that looks red and thick and is covered with silvery scales. It first appears on the elbows and knees, but can spread to other parts of the limbs and even the trunk. Certain forms affect particular areas like the hands, scalp or the joints.

"Patients with psoriasis have very poor quality of life because it’s very obvious and it makes the patient extraordinarily self-conscious," Alexiades-Armenakas said.

Although there are an array of skin conditions that can plague humans, treatment options for some, including acne, eczema and dermatitis have improved. If you suspect you have any of these conditions, see a dermatologist immediately to evaluate your treatment options.