Why a GPP Diagnosis Is Challenging

Cases can vary, Gelfand says. With some people, GPP “smolders,” causing discomfort and only sometimes resulting in flares. For others, the onset is abrupt. Pustules form within hours, and the skin will ooze fluid, he says. Urgent medical attention is crucial. 

“They need to get rapid control of that inflammation because it can lead to infection and can result in other issues: dehydration, decreased kidney function, inflammation elsewhere in the joints and lungs,” Gelfand says. “It’s as close to a medical emergency as we have in dermatology.”

In the days before steroids, the inflammation would be overwhelming and affect the skin badly. People died from it, he says. That seldom happens today, but it’s still important to rapidly diagnose and treat GPP. 

The GPP Diagnosis

There are many cases of people bouncing among doctors, as Reisner did. Most people consult their primary care doctor – or in extreme cases, emergency room doctors. Because of the lack of awareness surrounding GPP, they’re misdiagnosed, says Tina Bhutani, MD, a clinical researcher practicing at Synergy Dermatology and former co-director of the Psoriasis and Skin Treatment Center at the University of California San Francisco. 

They may arrive at the doctor’s office with a rash or the early formation of pustules, but they “very quickly go downhill,” she says. There’s no real test for GPP, but international psoriasis experts are “working toward more unifying guidelines.”

Efforts to develop genetic testing are underway as well, but those tests focus on one gene, a primary culprit in GPP, where many genes have been implicated, Bhutani says. Genetic testing may be more useful for research purposes. From a clinical standpoint, she says, “it might not be necessary unless they come up with more sensitive gene testing.”

However, dermatologists familiar with the disease can spot it on sight. Still, they may run blood tests, skin biopsies, or cultures on the pustules to rule out infection and other conditions that mimic GPP, including plaque psoriasis.

“We also want to see if we can find the trigger, if there is a trigger,” says Bhutani. 

There are many triggers, the main one being genetics. The most common genetic trigger can lead to unregulated production of chemical messengers in the immune system known as cytokines. This causes the skin to become inflamed. Additional triggers include:

• Medications such as NSAIDs, antihypertensives, antimicrobials, anti-platelet agents, swine flu and COVID-19 vaccinations, morphine, lithium, potassium iodide, and hydroxychloroquine. Also, quickly ending corticosteroids can serve as a trigger. 
• Other conditions such as fungal skin and nail infections, streptococcal infections, chickenpox, shingles, and the Epstein-Barr virus. 
• Factors like stress, pregnancy, calcium deficiency, sunburns, stem cell transplants, and menstruation.

“If you’re even suspecting GPP to be the diagnosis … get a dermatologist involved as quickly as possible to ensure the patient is getting the most appropriate treatments as quickly as possible,” says Bhutani.  

The Importance of Quick Diagnosis

Delays in diagnoses can happen for many reasons. For example, in people of color, a person’s dark skin may not show redness as much as someone with lighter skin. Complications of delayed care can include bacterial blood infections, nerve damage, intestinal disease, pancreatitis, cardiac failure, and liver impairment. In rare cases, the heart and lungs can stop working during GPP’s acute eruptive phase and can lead to death. 

Even when people find the right doctor, insurance hurdles can make it difficult to treat them quickly as an outpatient. Doctors may hospitalize people so everything needed to stabilize and treat them is covered, says Bhutani. That could include corticosteroids, biologics, or a monoclonal antibody like spesolimab that blocks the elevated genetic signaling causing the immune response and inflammation.

The cost of hospital treatment is much higher, says Bhutani, but “we don’t have time for insurance delays.”

Reisner knows how quickly things can go wrong. Back in 2005, before he found his “godsend” doctor, he had a flare. First came the itch, and “I scratched it and then it turned into like a pimple,” he explains. The pustules formed, cracked, and dried. The pain was similar to “a paper cut times 10,000” all over his body.

At the time, he ran an automotive repair shop. His wife and caregiver of 38 years, Denise, covered him in creams and wrapped him in plastic wrap. Both thought they were doing something helpful by protecting him from the dirt and grease of the tires and brakes he was changing. They were wrong. 

“What I did was trap everything in so all the sweat and everything that was trying to get out – the stuff that was bad – was going right back in,” says Reisner. 

It was a dire situation, requiring hospitalization and 11 days of “gnarly” antibiotics and steroids. Doctors were eventually able to pull him out of it, he says, “but because it wasn’t treated the right way, that’s what happened.”

The Right Diagnosis Can Change Someone’s Life 

Before Reisner realized his condition, the GPP was very intense. He had a hard time doing anything and developed several other conditions: high blood pressure and cholesterol, obesity, diabetes, and heart problems among them. Having psoriatic arthritis as well didn’t help. 

Now that he’s found the right doctor and care, he’s changed his lifestyle. He watches what he eats and doesn’t drink alcohol or smoke. He takes topical and oral medications and spends time each week in a light booth, where ultraviolet rays slow the growth of affected skin cells. Walking every day eases the arthritis and has helped slim him down from 300 pounds to 170.

“I have noticed a difference in my flares. I still get them, but they’re not as intense, and overall, I just feel better,” says Reisner. 

He’s also a patient-advocate, which has taught him the value of community. He and others with GPP share little hacks. Reisner has advised his counterparts to change their home’s door knobs to levers, so they can easily push them down when painful pustules emerge on their hands. He also emphasizes the importance of finding and listening to a good doctor.

The work gives him purpose. He knows what it’s like to look in the mirror and see himself covered in red, scaly skin. He knows what it’s like to think he can’t endure anymore. He now tells people, “You woke up this morning. It’s a good day. Put your shoes on, and let’s go.”

Now, he says, it all makes sense: “I understand why I had to go through this: because I was supposed to be a patient advocate. … It’s made me feel good about myself. I now wear my psoriasis with a badge of honor.”