Difference Between Psoriasis, Rosacea, Dermatitis, and Eczema

How to Tell the Difference

Got a rash? Don't freak out. Before you reach for a slew of steroids and creams to cure it, keep in mind that treating unexpected skin irritation begins with a proper diagnosis. Unfortunately, because irritated skin often shares the same symptoms, it can be one of the hardest conditions to identify. We asked dermatologists to break down four of the most frequently misdiagnosed skincare conditions—eczema, rosacea, psoriasis, and dermatitis—and how to differentiate them. 

Identifying Your Skin Condition

According to Naissan O. Wesley, MD, a board-certified dermatologist in Beverly Hills, Calif., these four skin conditions are often incorrectly umbrellaed under the term dermatitis. "Inflammation of the skin can include a variety of rashes, including psoriasis, eczema, atopic dermatitis, contact dermatitis, among others," he says. 

"Skin conditions either come from the outside in or the inside out," adds Vanessa Coppola, MD, a board certified nurse practitioner and aesthetic specialist. "You're either coming into contact with something in the environment that's causing a disruption, or it's an innate immune response."

Because these conditions can occur at any age and at any time, knowing which condition you have ultimately boils down to the location, appearance, and symptoms of your skin irritation. Amy S. Ross, MD, a board-certified dermatologist with the American Academy of Dermatology, points out that some people will experience flares, where symptoms are more pronounced and then go away, or have chronic conditions that require constant care. 

As soon as you notice an instance of skin irritation, it's important to keep a close eye on the area. "We usually recommend taking a picture of the rash so you can monitor the progression of the condition compared to what it looked like when it initially appeared," says Dr. Ross. "Also, look for the right over-the-counter treatments. There is no harm in trying an emollient cream, topical hydrocortisone, or antifungal cream for a few days."

Psoriasis

Put simply, psoriasis is a condition in which your immune system gets angry at your skin and attacks it. The most common variation is plaque psoriasis, which appears as thick, raised plaques on the skin. These plaques are often silvery in nature—and very, very itchy. "Psoriasis usually shows up on or around the scalp, but is also common behind the ears, on the elbows, knees, and lower back," says Dr. Ross.   

If you're dealing with a suspected case of psoriasis, it may be safer to see a dermatologist from the start. While a variety of topical treatments may help improve symptoms of psoriasis, it's important to understand that your case is internal. Severe psoriasis may require treatment with powerful medications that suppress your immune system (like Trexall, Dithranol, or Sandimmune).

Rosacea

Rosacea is most commonly identified by severe flushing of the skin—it can also cause acne-like bumps, hotness, and in extremely rare cases, swelling. These symptoms often come and go, depending on a person's triggers, which can range from spicy foods to excess stress. According to Dr. Coppola, the most telling indicator of rosacea versus other conditions is its location. "Rosacea is usually limited to the face and the eyes," she says. "If you suspect rosacea, check to see if your face is flushed and if your capillaries are broken." However, in making this consideration, she notes to be mindful of your most recent activities and schedule, and whether the condition could be a result of alcohol consumption, lack of sleep, or heat exposure.

If your inflammation is mild in nature, Dr. Wesley suggests using an antibiotic or lightweight moisturizer, combined with a skin calming serum. "Over-the-counter Vanicream products, including the moisturizing cream, is well-tolerated by people with rosacea," he says. Alternatively, you can also ask your doctor about laser treatment, blood pressure medication, or electrodesiccation—use of a tiny needle that delivers electricity to the blood vessel to destroy it—for long-term results. 

Dermatitis 

There are two types of dermatitis, and in most cases, it's likely that your dermatitis is a one-time thing, says Dr. Wesley. Allergic contact dermatitis, which manifests as itchy red patches and blisters, is caused by an allergic reaction to a material, such as jewelry metals, cosmetic products, fragrances, and preservatives. Keep in mind that it can take several days after exposure for a rash to develop.

Similarly, irritant contact dermatitis occurs when a chemical substance (i.e., acids, alkaline, hair dyes, resins, etc.) irritates the skin's outer layers. The rash is more painful than itchy, and is typically short-lived. The best way to identify—and eliminate—any form of dermatitis is to consider any new products or environments you have been exposed to recently. You may need to use some process of elimination, but this can help you find the incriminating culprit. 

Eczema 

Eczema can occur at all ages and tends to run in families, especially those prone to allergies and asthma. The condition often appears as dry, red, and itchy skin that worsens with excessive itching. Affected areas may also become cracked, discolored, blistered, scaly, and may weep clear fluid. Although eczema can crop up anywhere, Dr. Wesley suggests looking for markings on the crease of your wrists, elbows, and knees, as well as reddening on the ankles, face, and neck.

If you struggle with chronic eczema, Dr. Wesley advises against using harsh, overly drying cleansers, as these can further worsen the condition. Instead, moisturize regularly with gentle, fragrance-free products that have the National Eczema Seal of Acceptance. "Maintaining the skin barrier with good moisturization is a key component in reducing and preventing symptoms," she says.

RELATED: 5 Most Moisturizing Hand Soaps for Eczema That Won't Dry out Your Skin

When to See a Dermatologist

"The duration of skin inflammation is often dependent on the individual, says Dr. Wesley. "Stress, lifestyle, diet, and types of treatments all play a role as to how severely and how long people suffer from these conditions. In any case, living with psoriasis, dermatitis, eczema, and rosacea shouldn't have to come with major disruptions. 

In determining whether to seek professional medical treatment, it's best to monitor your symptoms. If your particular skin condition begins to crust, ooze, or grow rapidly in size—or it's hindering your day-to-day activities—Dr. Coppola advises seeking out a dermatologist. 

Dr. Wesley points to the duration of your condition as another indicator, saying, "If a skin condition has been present for several months and is not resolving, or a new mole or growth has appeared, I would recommend seeking professional expertise sooner rather than later."