|By Claire Gillespie
Pop quiz: Can you tell the difference between psoriasis and eczema? As if these chronic skin issues weren’t frustrating enough, they can also be incredibly confusing. “Both eczema and psoriasis cause red, scaly areas on the skin, and to the untrained eye, they can look similar,” board-certified dermatologist Alan J. Parks, M.D., tells SELF. Here’s how to figure out which is which, along with the best ways to actually treat these annoying skin conditions.
Psoriasis comes in many forms, each with it’s own set of symptoms.
Psoriasis is an autoimmune condition that affects about 7.5 million Americans, according to the American Academy of Dermatology. It happens when the skin cells go through their life cycle more quickly than normal. Typically, it takes about a month for skin cells to regenerate, but in people with psoriasis, this process happens every three to four days, according to the Cleveland Clinic.
The most common type of psoriasis is plaque psoriasis, per the Mayo Clinic. It appears as raised, red patches with a silvery white coating of dead skin cells, and is most often found on the scalp, elbows, knees, lower back, and genitals, but it can show up anywhere on your body. Unfortunately, the patches may be painful and itchy, and are liable to cracking and bleeding.
There are other, less common forms of psoriasis. Guttate psoriasis, which often begins in childhood or young adulthood and can be triggered by a strep infection, appears as small, droplike lesions. Inverse psoriasis shows up as a smooth, shiny, red rash in body folds, such as under the arms or breasts. Pustular psoriasis, which can present on the palms of the hands and soles of the feet, is characterized by noninfectious, pus-filled blisters, according to John Hopkins Medicine. The most severe, and rarest, type of psoriasis is erythrodermic psoriasis, which results in widespread, fiery redness over most of the body. It can cause severe itching and pain, and if you think you’re having an erythrodermic psoriasis flare-up, you should seek medical attention immediately. (FYI: You can find more information and photos of each type from the Mayo Clinic here.)
Eczema is much more common than psoriasis, and it also has a few different ways of showing up on the skin.
According to the most recent estimate available, over 30 million Americans have some form of eczema, which is really the collective name for a group of conditions that cause the skin to become red, itchy, and inflamed. “When most people say ‘eczema,’ they usually mean atopic dermatitis,” Todd Minars, M.D., an assistant clinical professor of dermatology at University of Miami School of Medicine, tells SELF. The AAD calls atopic dermatitis “the itch that rashes” to emphasize how uncomfortable this condition’s characteristic dry, red, scaly patches can be. Symptoms of atopic dermatitis can include dry, itchy patches of skin that are red to brownish-gray, small raised bumps, and cracked or scaly skin. (FYI: You can find more information and photos of eczema from the Mayo Clinic here.)
Contact dermatitis is another kind of eczema. According to the AAD, contact dermatitis is a reaction that happens when the skin comes into contact with irritating substances, such as solvents, poison ivy, and detergents, and it typically affects the part of the body that touched the irritant, according to the Mayo Clinic. Its symptoms are redness or rash, burning or swelling, and blisters that may weep or crust over. Allergic contact dermatitis takes it one step further, happening when exposure to an allergen triggers an allergic reaction.
Dyshidrotic eczema is yet another form of this condition. It appears as small, itchy blisters on the edges of the fingers, toes, palms, and soles of the feet, and may be triggered by stress, allergies, or exposure to metals like nickel and cobalt, according to the Mayo Clinic. Symptoms include pain, itching, redness, flaking, and scaly, cracked skin.
These two skin problems have different causes and can appear in different stages of your life.
Psoriasis typically strikes when someone is between the ages of 15 and 35, according to the U.S. National Library of Medicine, but it can affect anyone at any age. “What we do know is that psoriasis is immune-mediated, meaning there is some imbalance in the immune system, which leads to inflamed skin,” dermatologist and National Psoriasis Foundation medical board member Jashin Wu, M.D., tells SELF. “It tends to run in families, but there may not be straightforward patterns of inheritance. One well-known trigger is strep throat infections, but not all new cases of psoriasis result from strep throat.”
A textbook case of eczema begins during infancy or early childhood, Dr. Minars says. “There are some controversies as to whether eczema is primarily an immune-mediated disease or a skin-barrier defect disease,” Dr. Wu says. “Like psoriasis, it also tends to run in families.”
There’s no doubt that living with psoriasis and eczema can be stressful, and their connection to stress has been widely discussed in the dermatology community.
Although experts often advise people with psoriasis and eczema to avoid stressful situations, a lot remains to be proven about exactly how stress can influence these conditions. A November 2017 meta-analysis in the British Journal of Dermatology evaluated 39 studies with over 32,500 patients, concluding that “No convincing evidence exists that preceding stress is strongly associated with psoriasis exacerbation/onset.” As for eczema, an October 2017 study in the International Journal of Molecular Sciences reported that psychological stress may exacerbate atopic dermatitis, and it might be mediated by the hypothalamic–pituitary–adrenal (HPA) axis.
Just because science hasn’t fully clarified the role stress plays in these conditions doesn’t mean the link doesn’t exist. Dr. Wu says he’s seen patients experience stress-related psoriasis or eczema flare-ups in the past, and the American Academy of Dermatology mentions stress when discussing both psoriasis and eczema.
Though psoriasis and eczema are entirely different conditions, treatment for the two is often similar.
While there’s no cure for either condition, they can be treated. Topical medications to reduce inflammation, like corticosteroids and retinoids, are some of the first lines of defense for both conditions, according to the Mayo Clinic. Doctors may also prescribe drugs to suppress your immune system if necessary. Phototherapy, where a special machine emits ultraviolet light onto the skin to help reduce itching and inflammation, is also a treatment option for both psoriasis and eczema.
Although psoriasis and eczema are both frustrating, irritating conditions, they shouldn’t be life-ruiners. If you’re struggling with managing your psoriasis or eczema, see a dermatologist, who can help determine the best treatment plan for you.