Is it psoriasis or eczema? New test provides answers

| Emily Delzell

A new genetic test developed by a group of German researchers may help dermatologists tell psoriasis from eczema, according to a study published in July in Science and Translational Medicine that identified genes specific to each condition.

Psoriasis and eczema are both can cause red, raised patches on the skin, and even experienced dermatologists can have a hard time telling the two apart, especially when the affected skin is on the hands or scalp, said study author Dr. Kilian Eyerich.

The study showed that, while psoriasis and eczema both involve inflammation, the responses of the genes involved in each disease are quite different—and sometimes create opposing reactions. This means treating patients incorrectly can cause problems, Eyerich said.

“Modern therapies for both conditions are so specific they won’t work if the patient is misdiagnosed, and incorrect treatment can even worsen the disease because each condition is driven by distinct, even antagonistic, immune responses,” he said.

Both psoriasis and eczema involve complicated genetic processes that vary greatly from person to person, so pinpointing the specific genes at work in each has been difficult.

It’s rare for one person to have both conditions, but the scientists identified 24 people with psoriasis and eczema. They compared skin samples of psoriasis and eczema from each individuals and with the person’s unaffected skin. This allowed them to cut out a number of genetic variables and identify distinct genetic signatures for psoriasis and eczema, Eyerich said.

The researchers selected two genes identified in the study—one reliably specific to psoriasis, the other to eczema—to create the diagnostic test. They are now simplifying the test so dermatologists can use it easily and quickly in their offices, and Eyerich said it could be available in about a year.

Many of the genes identified in the study as specific to psoriasis regulate metabolic functions, confirming the known link between psoriasis and metabolic syndrome—a cluster of risk factors for cardiovascular disease that includes obesity, high blood sugar and cholesterol.

In contrast, eczema-related genes included those related to the epidermis, the outermost layer of skin cells that acts as a barrier to water loss and infection.

“This study allows a deep insight into what happens in psoriatic skin,” Eyerich said. “While many of the key genes are already targeted by modern therapies, there are additional factors that may lead to even better therapies.”


Driving discovery, creating community

For more than 50 years, we’ve been driving efforts to cure psoriatic disease and improve the lives of those affected. But there’s still plenty to do! Learn how you can help our advocacy team shape the laws and policies that affect people with psoriasis and psoriatic arthritis – in your state and across the country. Help us raise funds to support research by joining Team NPF, where you can walk, run, cycle, play bingo or create your own fundraising event. If you or someone you love needs free, personalized support for living a healthier life with psoriatic disease, contact our Patient Navigation Center. And keep the National Psoriasis Foundation going strong by making a donation today. Together, we will find a cure.

Recent Advance Posts

Doctor and patient in the exam room
What does your primary care provider have to do with managing your psoriatic...
People meeting around a table for discussion
Have we developed the tools to turn psoriasis and psoriatic arthritis into...
The Patient Navigation Center helps a woman whose PsA went undiagnosed for...
hands holding signs numbers 1 through 5
Psoriatic arthritis is a complicated disease. Learn something new today.
FDA approval stamp
Clinical trial data show drug may help you achieve clear skin.
Test tubes in a lab
A study of immune cells points to clues on how psoriasis makes a person more...
Man with joint pain
A physical therapist weighs in on the exercises and activities you can do even...
NPF volunteer at a Team NPF Cycle event
When a new doctor finally took a close look at all of Erin Faulhaber’s symptoms...
Advocates visiting Congress
Forced to retire early because of his PsA, former diplomat Stephen Keat...