What is pustular psoriasis?
Pustular psoriasis is a rare type of psoriasis—a chronic, autoimmune skin disorder. It is different from plaque psoriasis, the most common form of the disease. Instead of red, silvery, scaly plaques, pustular psoriasis causes pus-filled bumps—or pustules. Red, tender skin surrounds the pustules, which can appear suddenly after the skin turns red. Pustular psoriasis on the hands and feet are more common than other sites.
Adults are most likely to develop pustular psoriasis. It affects different races and males and females equally. People with pustular psoriasis may also have other forms of psoriasis, such as plaque psoriasis or erythrodermic psoriasis. Pustular psoriasis may precede or follow the development of other types of psoriasis, as well.
Pustular psoriasis is not an infection and is not contagious. White blood cells make up the pus inside the bumps. The pus does not contain bacteria or other microbes. However, pustular psoriasis can be serious and even life threatening depending on the specific subtype.
Acropustulosis affects the tips of the fingers and toes, causing pain and disability. It is a rare subtype that can cause nail deformity or destruction and bone changes in severe cases. Acrodermatitis continua of Hallopeau is another name for this form.
Generalized pustular psoriasis (GPP) is also rare, but it is a medical emergency. It causes widespread red, tender skin with pustules that can cover most of the body. Pustules burst open and dry, causing the skin to dry out and slough or peel. This destroys the skin’s protective barrier and leaves a shiny, glazed-looking layer. Life-threatening dehydration, rapid heart rate, fever, chills, muscle weakness, exhaustion, along with severe itching, can occur. Seek immediate medical care (call 911) for symptoms of GPP. Von Zumbusch pustular psoriasis is another name for GPP.
Impetigo herpetiformis only affects pregnant women, usually during the third trimester. It is rare and develops on the inner thighs and groin. Pustules can also appear in the mouth and under the nails. It is unclear whether this form is actually GPP or if it is a separate form. Either way, it carries risks for the unborn baby. Seek immediate medical care if you are pregnant and develop these pustules.
Palmoplantar pustulosis (PPP) occurs on the palms of the hands and soles of the feet. The base of the thumb and sides of the heels are common sites. PPP tends to go in cycles, with periods of increased activity and low activity. It affects about 5% of people with psoriasis.
Pustular psoriasis treatment depends on the subtype. Topical treatments, light therapy, and systemic medicines may be necessary. Often, doctors combine treatment options because pustular psoriasis can be stubborn. GPP requires emergency medical care.
What are the symptoms of pustular psoriasis?
Pustular psoriasis causes pus-filled bumps—or pustules—surrounded by red, tender skin. While it can look like an infection, the pus only contains white blood cells, not bacteria or other germs.
The bumps can appear suddenly, within a few hours of the skin becoming red and tender. They can burst and dry, causing brown dots and possibly scale (the result of dead skin cells). The condition usually cycles through periods of red, tender skin and the appearance of pustules. It most commonly affects the hands and feet and can be painful and disabling.
Pustular psoriasis can resemble other skin conditions. A dermatologist is oftentimes the best type of provider for a timely and correct diagnosis.
Serious symptoms that might indicate a life-threatening condition
In rare cases, pustular psoriasis can be life threatening. Seek immediate medical care (call 911) if you, or someone you are with, have symptoms of GPP. This includes pustules surrounded by red, tender skin that covers most of the body. Other symptoms include:
What causes pustular psoriasis?
Doctors know that psoriatic disease, including pustular psoriasis, is an autoimmune disorder. This means the immune system goes haywire and starts attacking the body’s own cells as if they were invaders. However, the exact cause of the autoimmune process remains unclear. It likely involves a combination of genetic and environmental factors.
Like other forms of psoriasis, certain things can trigger the autoimmune response. Known pustular psoriasis triggers include:
Infections and skin irritation
Pregnancy, especially during the third trimester
Rebound phenomenon after abruptly stopping systemic psoriasis treatment or potent topical steroids
Too much UV light exposure and certain medications
What are the risk factors for pustular psoriasis?
Risk factors for pustular psoriasis are not well understood. It is more common in adults, but can affect children in rare cases. There does not appear to be any differences in occurrence between races or sexes. It may possibly be more common in smokers. Pregnancy is a risk factor for impetigo herpetiformis.
Reducing your risk of pustular psoriasis
It may not be possible to prevent pustular psoriasis. Some people already have another form of psoriasis when it occurs. For others, it is the first sign of psoriatic disease. If you have psoriasis, talk with your doctor about your risk of pustular psoriasis. Avoiding known triggers may help lower your risk.
How is pustular psoriasis treated?
Pustular psoriasis can be hard to treat. A dermatologist’s expertise is necessary to effectively control the condition. In general, doctors combine or rotate the following treatment options:
Biologics, including adalimumab (Humira), etanercept (Enbrel), and infliximab (Remicade)
Oral medicines, including acitretin (Soriatane), cyclosporin (Gengraf, Neoral, Sandimmune), methotrexate (Rheumatrex, Trexall), and apremilast (Otezla)
Topical medicines, including corticosteroids, vitamin D, and salicylic acid
Ultraviolet light therapy, which may be combined with the light-sensitizing drug psoralen
GPP requires emergency medical treatment. The goals are to restore fluid balance, prevent infection with antibiotics, and stabilize body temperature and vital signs. Doctors will also use potent medicines to control the immune response.
What are the potential complications of pustular psoriasis?
Infection is a possible complication whenever there is damage to the skin barrier. So, pustular psoriasis increases the risk of a secondary skin infection. Hair loss and nail loss are also possible. Pustular psoriasis flares usually recur throughout a person’s lifetime.
GPP carries a higher risk of complications, especially in older adults. Death is possible from sepsis and organ failure, including the kidneys, liver, heart and lungs.