What Is Generalized Pustular Psoriasis (GPP)? Symptoms, Causes, Diagnosis, Treatment, and Prevention
Generalized pustular psoriasis (GPP) or erythrodermic psoriasis is a severe form of the autoimmune disease psoriasis. Although it is the rarest form of psoriasis, it can spread quickly and requires immediate medical attention.
Unlike localized pustular psoriasis, which occurs on one area of the body, a GPP flare involves a widespread rash with pustules, or small bumps containing pus (a white or yellow fluid filled with dead white blood cells).
“In psoriasis, there are microscopic little collections of pus cells,” says Steven Feldman, MD, PhD, a dermatologist who specializes in psoriasis at Atrium Health Wake Forest Baptist in Winston-Salem, North Carolina. “But in generalized pustular psoriasis, which is a very abrupt and severe flare, people get the psoriasis all over their body, and those little microscopic pus cells get so large that they are visible with the naked eye.”
In severe cases, GPP can become life-threatening if left untreated.
Types of GPP include:
Acute GPP
Annular pustular psoriasis
Localized or chronic acral GPP
Pustular psoriasis of pregnancy
Infantile and juvenile pustular psoriasis
Mixed GPP
Acute GPP
Acute GPP is also called GPP of von Zumbusch, named after the dermatologist who first described it in 1910. It starts rapidly within seven days of a flare. It is the most severe and most common form of the disease, affecting about 90 percent of people with GPP.
Annular Pustular Psoriasis
Annular pustular psoriasis is a milder category of GPP. It is limited and recurrent, typically flaring between 7 to 90 days after the onset of GPP.
Localized or Chronic Acral GPP
Chronic acral GPP flares over three months. Lesions appear on the feet, hands, arms, legs, and other acral extremities. Over time, it can spread elsewhere on the body.
Pustular Psoriasis of Pregnancy
Pustular psoriasis during pregnancy is called impetigo herpetiformis. It typically starts in the final trimester and is caused by and made worse by the pregnancy. It can lead to placental insufficiency, stillbirth, fetal abnormalities, and early death.
Infantile and Juvenile Pustular Psoriasis
GPP in children typically starts between the ages of 3 and 16. It is estimated to comprise 0.3 to 7 percent of child psoriasis cases. Although it can be life-threatening, GPP in children resolves on its own more often than in adult cases and is more likely to enter remission, as well.
Mixed GPP
It is also possible to have mixed GPP, in which you present symptoms of more than one subtype.
GPP involves the rapid onset of inflamed skin — sometimes in just two hours — and small pustules (2 to 3 millimeters), often covering large areas of the body. Pustules may expand, merge, and burst, which can expose raw and scaly skin.
During a GPP episode, you may develop symptoms associated with systemic inflammation that may include:
Fever
Chills and shivers
Intense itching
Rapid pulse
Fatigue
Headache
Nausea
Muscle weakness
Joint pain
If you think you have GPP, contact your healthcare provider immediately, because the condition can lead to potentially life-threatening complications. Although the condition is somewhat rare, you may be admitted to the hospital for monitoring potential complications.
Your symptoms and signs may also differ based on the specific type of GPP you develop. Chronic acral GPP, for example, may start on your hands or feet before spreading to other larger areas of the body.
It may also be short term (acute) or long term (chronic). Some people may experience sudden attacks or flares of symptoms for several weeks at a time followed by periods of remission where they recover fully or partially.
Research is inconclusive about why a person develops GPP, but it indicates that GPP comes from genetic mutations. This means it may be passed down from family members or occur spontaneously.
“People have psoriasis in part due to their genetics, and so they’ll be predisposed to having psoriasis, but then they’ll get an infection or be exposed to some drug that activates their immune system and causes the psoriasis to severely flare up,” Dr. Feldman says.
A urinary tract infection or pneumonia, for instance, could cause somebody who has psoriasis to experience a GPP flare.
Potential GPP flare triggers include:
Illness or infection
Use of certain medications These may include withdrawal from corticosteroid treatment, as well as antibiotics and antifungals, Feldman says.
Pregnancy
Psychological stress
Hypocalcemia This is a condition that results from an abnormally low level of calcium in your blood
To diagnose GPP, a doctor will perform a physical exam, ask about your medical history, review symptoms, examine a sample of skin tissue (biopsy), and possibly test pustules to rule out other potential causes. Psoriasis or a history of psoriasis could indicate GPP for some but not all people.
Doctors unfamiliar with GPP may misdiagnose symptoms as an infection or simple psoriasis, especially in patients experiencing a flare for the first time.
Patients visiting the doctor with GPP often are experiencing serious symptoms. In addition to making a diagnosis, your healthcare provider may decide if you need to be admitted to the hospital.
There is no cure for GPP. The condition can relapse or recur for no known reason (idiopathic) or because of exposure to a trigger. In some cases GPP can be persistent, with symptoms lasting for months.
Because there are few universal guidelines for diagnosis, flares may be treated aggressively or go away on their own, in some cases.
GPP is unpredictable and highly variable. Some people may experience a flare every few years; others may have multiple flares per year. About 50 percent of GPP flares require hospitalization, and a person with GPP may require hospitalization for a flare at least once every five years.
When a GPP flare occurs, it’s important to get it under control as soon as possible to avoid complications, Feldman says.
The availability of treatments has reduced the mortality rate from 32 percent in 1971 to closer to 5 to 10 percent, though complications may occur from GPP itself as well as from side effects of steroid treatments.
Spesolimab (Spevigo) for GPP
The U.S. Food and Drug Administration approved spesolimab (Spevigo) in September 2022, making it the first and only treatment approved specifically for GPP in U.S. adults.
Delivered by injection, the drug blocks the activation of the interleukin-36 receptor (IL-36R), a key part of a signaling pathway within the immune system involved in GPP.
Psoriasis Medications
Doctors also treat GPP with medications developed for severe psoriasis treatment. Options include:
Oral retinoid Oral retinoids are derived from vitamin A. They are usually reserved for severe psoriasis, and research about their efficacy is limited.
Biologics Biologics target the part of the immune system that is overactive because of psoriasis, decreasing inflammation and bumps quickly. Medications in this class include:
infliximab (Remicade)
adalimumab (Humira)
etanercept (Enbrel)
apremilast (Otezla) This drug works by controlling inflammation in the immune cells.
methotrexate(Jylamvo, Otrexup, Rasuvo) This strong medication suppresses the overactive immune system.
cyclosporine (Sandimmune, Neoral) This fast-acting medication also works by suppressing the immune system, Feldman says.
You may be prescribed multiple medications at once. Reach out to your doctor or dermatologist about potential side effects from these medications.
In addition to these systemic treatments that focus on the immune system, physicians also need to address specific skin issues.
“Often, the skin of someone with GPP is treated in the same way that a person with severe burns would be treated — with special kinds of bandages, special emollients, and antibiotics,” Feldman says.
GPP triggers can vary from person to person; trying to avoid or limit exposure to known triggers can help reduce the risk of a flare.
“If [the trigger is] a medication, then you want to avoid that medication,” Feldman says.
If infections are a trigger, that’s more difficult. You can’t always avoid getting them. But if you do, your doctor should monitor you closely, Feldman says.
You may want to talk to your doctor or healthcare provider about vaccinations as a means to help prevent infections, such as the flu, COVID-19, and others.
Experts also caution against using systemic steroids if you have psoriasis.
If you are living with GPP, you can help manage the condition through some general lifestyle changes, including:
Feldman says, however, that advances in medications may be making these complications less common.
GPP is rare, affecting less than 1 percent of people in the U.S., or between 1.8 and 124 people out of every 1 million. It can occur at any age, but it often peaks between the ages of 40 and 59. Some studies show that women are twice as likely to develop GPP than men, but this data is inconsistent across studies.
GPP can affect people of any skin color, Feldman says.
Some evidence suggests that gene mutations that may contribute to causing GPP may be more common in people who are from the following countries:
United Kingdom
Germany
Tunisia
Malaysia
China
Japan
It’s estimated that 54.4 percent of people with GPP also have plaque psoriasis. About 80 to 90 percent of people living with psoriasis have plaque psoriasis.
Plaques are raised, inflamed, and scaly patches of skin that can be painful and itchy. On white skin, they usually look red with a silvery white buildup of scales. On darker skin tones, the plaques may appear thicker and more of a purple, gray, or dark brown color.
Plaques can appear anywhere on the body but they occur most often on the scalp, knees, elbows, and torso.
Mental health can play an important role in managing flares, treatment, and stress.
You may find support from friends and family, but you may also benefit from finding other people near you or online who also live with psoriasis.
National Psoriasis Foundation The National Psoriasis Foundation offers help with finding other people living with psoriasis, as well as ways to get involved in its community and to seek help for children and teens.
Inspire Community Forum Inspire’s network of online support groups includes a forum designed for people living with psoriasis.
