Atopic Dermatitis vs. Psoriasis

Red or silvery scales on the skin are typical features that distinguish psoriasis from atopic dermatitis.

Psoriasisandatopic dermatitisare common, long-term skin diseases. Both are noncontagious. Because both therasheslook somewhat similar, the diagnosis may be difficult at first glance, and a biopsy of the skin remains the last resort. However, certain things can help differentiate between the two before the doctor orders a biopsy.

Atopic dermatitisis not only the most common type ofeczemabut also a skin condition more common thanpsoriasisin the United States.Psoriasisaffects more than 8 million people, whereasatopic dermatitisaffects around 16.5 million people.

Doctors do not know the exact cause ofatopic dermatitis．遗传和环境因素found to be the triggering factors.

Researchers have come across some genetic mutations that alter the protective layer of the skin. This can allow the skin to be affected by triggers:

• Environmental factors
• Irritants (certain fabrics, soaps, chemicals, and household cleaners)
• Food allergens (milk, eggs, and peanuts)

The allergens differ among people. Other factors that trigger atopicdermatitisincludestress, infections, and exposure to heat.

People withdry skinor those living incold, dry regions seem to be more vulnerable to atopic dermatitis.

Atopic dermatitis can causeitchyskin with small, redbumps, or red to brownish-gray patches/rash．

• Itchingis often more common and severe thanpsoriasis．
• Scratching can cause the bumps to ooze fluid and crust over.
• The condition often begins during childhood and can continue up to adulthood.
• Common sites ofrashare the cheeks, inside of the elbows, behind the knees, and over the neck.
• A person with atopic dermatitis is also more likely to haveasthmaorhay fever．Moreover, a family history ofhay feverorasthmaputs the person at higher risk of atopic dermatitis.

Red or silvery scales (most commonly round) on the skin are typical features that distinguish psoriasis from atopic dermatitis. The most common type, plaque psoriasis, begins as small red round bumps that grow larger and form a scale. Scratching (often due toitching) can pull the scales off the skin and result in bleeding.

Psoriatic rash or patches can erupt anywhere on the skin, sometimes all over the body (including the nails). However, the common areas are as follows:

• Scalp
• Outer elbows
• Knees
• Over knuckles
• Back

The typical age of people who have psoriasis is between 15 and 25 years, but there is no age limit. Recent studies have reported that the condition is becoming more common in people older than 30 years.

In contrast to atopic dermatitis, psoriasis also affects the joints. The condition is known aspsoriatic arthritis．Apart from the joints, psoriasis also puts the affected people at risk of other health conditions that includediabetes,high blood pressure,heart disease, and Crohn's disease.

Most of the time, atopic dermatitis and psoriasis are diagnosed on the patient’s history, look, and distribution of the rash.

For atopic dermatitis, doctors may order anallergentest to identify the allergens the patients are sensitive to.

For patients who do not respond to the respective treatments, doctors scrape or cut a small piece of the patchy skin (biopsy). They then send it to the laboratory to look for specific cells under a microscope.

Many times, doctors treat atopic dermatitis in the same way as they treat psoriasis. The treatments common to both atomic dermatitis and psoriasis include:

• Avoidance of triggers and stressors
• Heavy moisturizers (liquid paraffin, urea, squalene, and beeswax)
• Corticosteroidcream (especially for atopic dermatitis)
• Antihistamines(medications to relieve the itching)
• Topical or oral antibiotics if there is bleeding and associated infection
• Immunomodulators creams or lotion (drugsthat target the immune system) for severe cases; sometimes, pills and injectables are often given for treatingsevere psoriasis．

Most people with psoriasis feel better when exposed to sunlight and warm climates. This aspect has led to the use of ultraviolet (UV) light therapy, which improves the skin condition in psoriasis.

Atopic dermatitis can flare up when exposed to hot climates (sweatingtriggers the rash). Light therapy can aggravate or induce the atopic dermatitis rash.