If you have skin symptoms, your doctor can figure out if eczema or psoriasis is the cause. They will also make sure that you get the right treatment.

In this article, you will learn about the differences between two chronic skin conditions: eczema and psoriasis. While they share symptoms, the conditions have different causes and treatments.

Symptoms

Eczema and psoriasis both cause you to get patches of inflamed, dry skin. Usually, you get these symptoms repeatedly over time. These episodes are called flares.

It can be hard for most people to tell the two skin conditions apart because they look similar. In fact, eczema and psoriasis are commonly misdiagnosed as each other in babies and kids.

However, to a person who is an expert in skin conditions (dermatologist), the differences between the two conditions are very obvious. Here are some of the key differences between eczema and psoriasis that they will look for.

Location

Psoriasis and eczema both cause rashes on your skin, but they show up in different places on your body.

Eczema is also called atopic dermatitis. It most often appears in the crook of the elbows and the backs of the knees. These parts of the body are called flexural surfaces. Psoriasis happens more often on the outside the forearms and elbows or the fronts of the knees and shins. These are the extensor surfaces of the body.

Psoriasis can also show up on your scalp, face, ears, neck, navel, arm, legs, feet, hands, ankles, and lower back. Eczema can also occur in these areas, but not as severely as psoriasis does.

Both diseases can cause ridges, discoloration, and thickening of the finger and toenails. However, only psoriasis causes little holes to appear in your nails (pitting of the nail plate).

Appearance

Both eczema and psoriasis can look like dry, red patches of thickened skin. When you look closer, though, the conditions look different.

Eczema can cause a rash, swelling, bumps, and generalized areas of darkened, leathery skin. Severe eczema can even ooze and crust over.

Psoriasis looks like well-defined patches of reddened skin that are covered with fine, silvery-white scales called plaques. The plaques bleed easily when scratched. They leave behind a pinpoint pattern of blood spots (Auspitz sign).

Scaling is a major sign of psoriasis. You may have scaling if you have eczema, but it doesn’t always happen.

Itching

Itching (pruritus) can be part of having psoriasis, but you’re more likely to have itchy skin if you have eczema. The itching from eczema can be severe.

If you have psoriasis, the itching is thought to happen because the inflammation in your skin bothers nerve receptors called nociceptors.

The nociceptors also get irritated if you have eczema. However, with eczema, that irritation is made worse by an antibody called immunoglobulin E (IgE). This antibody is linked to allergies. People with eczema have IgE antibodies, but people with psoriasis do not.

Causes

Both eczema and psoriasis are inflammatory skin conditions. That means that inflammation is what causes symptoms. However, the cause of the inflammation is different for each condition.

Eczema

Researchers think that eczema is caused by an overactive immune system. The immune system suddenly malfunctions and makes the body produce too many white blood cells called T-cells. These cells trigger an inflammatory response to defend the body against infection.

In a person with eczema, that extra inflammation causes cells in the lymph nodes to pump out IgE into the bloodstream. The IgE causes the cells of the outer layer of your skin (epidermal cells) to swell.

When this happens, bumps (papules) and fluid-filled pockets (vesicles) show up on the skin. It also causes the tissue to get thick (lichenification).

Psoriasis

Psoriasis is an autoimmune disease. With this condition, the body causes inflammation on purpose because it thinks there is a threat.

With psoriasis, the immune system suddenly sees normal skin cells as harmful. It attacks them by sending out T-cells.

The T-cells target new (immature) skin cells called keratinocytes. The inflammation makes the cells divide faster. Usually, it takes 28 to 30 days for new cells to turnover. In psoriasis, they will turn over every three to five days.

The cells are being made faster than the body can shed them. The cells push to the surface of the skin and form lesions.

Environmental Triggers

Most health conditions have more than one cause. The same is true for eczema and psoriasis. For example, genetics and environmental triggers seem to play a role in both conditions.

Scientists are still trying to understand how genetics is involved in psoriasis and eczema. They know a lot more about the things in someone’s environment that can trigger the conditions or make the symptoms worse.

Eczema Triggers

Since eczema is related to IgE antibodies, common allergens can trigger flares. These include:

Dust mitesPet danderPollenMoldDairy productsEggsNuts and seedsSoy productsWheat

Psoriasis Triggers

The things in your environment that could trigger psoriasis are not as specific as the things that seem to trigger eczema. However, many things that make other autoimmune diseases flare up also trigger psoriasis, including:

Infections Alcohol Smoking Skin trauma (the Koebner response) Certain medications (such as beta-blockers, lithium, and antimalarials)

Diagnosis

Your doctor will look at your skin and talk to you about your health to figure out what is causing your symptoms. They might also ask you about any medical conditions that run in your family.

Your doctor can also take a tiny piece of your skin to look at under a microscope (biopsy).

Eczema: The inflammation causes swelling of the outer layer of your skin called the epidermis. When this part of your skin swells, it’s called spongiosis. Under a microscope, there will be large spaces between the skin cells. There will also be visible papules and vesicles. Psoriasis: The inflammation causes your skin to make too many skin cells called keratinocytes. When this happens, it’s called hyperproduction. Under a microscope, the skin cells will look thick and compressed (acanthotic).

There are no blood tests or imaging tests that can give a sure diagnose of eczema and psoriasis.

Treatment

The goal of treatment is the same for eczema and psoriasis: to reduce inflammation and make the symptoms better. There are some treatments that work for both conditions, including:

Emollient-rich moisturizers Topical corticosteroids Oral antihistamines (to relieve itching) Staying away from triggers

However, the treatment that will work best for one condition is not always the one that works best for the other. Here are some key ways that treating eczema and psoriasis can be different.

Immunosuppressant drugs: Methotrexate and cyclosporine suppress the immune system as a whole. They can treat moderate to severe psoriasis. For people with eczema, the treatments are only used in severe cases. Phototherapy: Ultraviolet (UV) light therapy (phototherapy) is the main treatment for moderate to severe psoriasis. There is not much research on using it to treat eczema. Topical calcineurin inhibitors: Calcineurin inhibitors are medications that keep the T-cells in the body from being activated. This type of medication is approved by the U. S. Food and Drug Administration (FDA) to treat eczema. They can also be used for psoriasis, but without official FDA approval. This is called “off-label” treatment. Protopic (tacrolimus) and Elidel (pimecrolimus) are two examples of this type of medication. TNF inhibitors: Tumor necrosis factor (TNF) inhibitors block a key inflammatory compound that is linked to psoriasis. Medications like Humira (adalimumab) and Enbrel (etanercept) are examples of TNF inhibitors. This type of medication is not approved to treat eczema and can actually make it worse. The reason is that the inflammatory compounds in eczema (interleukins) are not the same as those in psoriasis. Janus kinase (JAK) inhibitors: JAK inhibitors are medications that selectively block immune signals which cause inflammation and itching. This type of medication includes Cibinqo (abrocitinib) and Rinvoq (upadacitinib), which are both approved by the FDA to treat moderate to severe eczema.

Summary

Eczema and psoriasis are chronic skin conditions. The symptoms can be similar, but the causes and treatments for the conditions are different. If you have skin symptoms like a rash, itching, bumps, or lesions, it’s important to see your doctor. They might have you see a doctor that is an expert in skin conditions (dermatologist).

Both eczema and psoriasis can be treated but in different ways. For example, there are different medications approved to treat each condition.

A Word From Verywell

Psoriasis and eczema are common conditions. If you have skin symptoms, you might wonder if one of these conditions could be the cause. Since they can look and feel similar, the only way to know for sure is to talk to your doctor.

Once you learn which condition you have, you can work with your doctor to manage it. Many steps that you can take will help whether you have eczema and psoriasis, such as avoiding things that trigger your symptoms.

However, it’s still important to know which condition you have because some treatments, like medications, are only meant for one or the other.