Types, symptoms and treatment of pustular psoriasis
You’ve probably heard of psoriasis, a chronic inflammatory disease that can cause itchy, scaly patches on your skin. Less well known is a rare form of the disease called pustular psoriasis, which affects about 1% of people with psoriasis.1
Pustular psoriasis is characterized by pustules or small pus-filled bumps that can be incredibly painful.2 Not surprisingly, they can seriously affect your quality of life, especially if the pustules are located on areas that need to withstand pressure, like the soles of your feet, or on highly visible skin, like your face. This condition can be rare, but it’s important to distinguish the symptoms of pustular psoriasis from an infection, as it can be easy to confuse the two. Here’s everything you need to know about pustular psoriasis, including symptoms, causes, and treatment.
What is pustular psoriasis? | What causes pustular psoriasis? | Pustular psoriasis types | Treatments for pustular psoriasis | What makes pustular psoriasis worse?
What is pustular psoriasis?
Pustular psoriasis is a rare type of psoriasis that likewise goes through periods of flare-ups and remissions. During a flare-up of pustular psoriasis, the inflamed skin will be covered with small pus-filled bumps, or pustules. These bumps can spread, join together and open up, according to the American Academy of Dermatology (AAD).
It is important to note that pustular psoriasis is not just a skin condition. “It’s a multisystem inflammatory disorder,” Dawn Davis, MD, pediatric and adult dermatologist at Mayo Clinic, tells SELF.3 “A lot of people assume that psoriasis is just limited to the skin, but there’s a growing understanding that it’s really a multi-organ disease that manifests most obviously in the skin.”
This means that the chronic inflammation associated with pustular psoriasis can also affect other parts of your body. Additionally, a growing body of research indicates that all forms of psoriasis are associated with various diseases involving chronic inflammation, such as inflammatory bowel disease, arthritis, and even cardiovascular disease.4 However, there is no evidence that pustular psoriasis causes other inflammatory diseases – researchers are still trying to figure out the link.
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What causes pustular psoriasis?
Experts don’t know the exact cause, but they do know that pustular psoriasis is the result of an overactive immune system attacking healthy cells in your body, according to the Centers for Disease Control and Prevention (CDC). The fluid that fills the pustules is made up of white blood cells, which are immune cells that the body normally sends out to fight infections.5
Although the causes of pustular psoriasis remain a mystery, experts have looked into a few risk factors for the disease. Research shows that pustular psoriasis is associated with genetic mutations in the CARD14 gene, which helps regulate genes responsible for the immune system, according to the NLM. People with these mutations may be susceptible to developing the disease, which can be triggered by a particular event, such as infection, smoking or pregnancy.6
Stopping certain medications — oral corticosteroids, in particular — is another common trigger for pustular psoriasis, Lawrence Green, MD, board-certified dermatologist and clinical professor of dermatology at the George Washington School of Medicine and board member of the American Academy of Dermatologists, says SELF. Oral corticosteroids are commonly prescribed to treat plaque psoriasis, and your immune system may have an adverse reaction when you finish drug therapy.7 This is why people usually suffer from both plaque psoriasis and pustular psoriasis.
Getting a diagnosis of pustular psoriasis can be tricky. It can be hard to tell at first glance (even for your doctor) whether the pus is a sign of infection or psoriasis. The only way to confirm is to culture the pus to see if there are bacteria inside. If it is pustular psoriasis, the bacterial culture will be negative because pustular psoriasis is not caused by an infection and is therefore not contagious. Another option is for your doctor to take a biopsy of your skin to examine under a microscope.
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What are the different types of pustular psoriasis and their symptoms?
All pustular psoriasis is characterized by fluid-filled pustules. To start, you may develop tender, reddened skin followed by pustules that usually appear a few hours after your first symptoms, according to the Mayo Clinic. “A lot of people suspect these bumps are an infection when in fact they’re not,” says Dr. Davis.
Often the pustules merge and then burst,8 resulting in a scaly, cracked and painful rash. More pustules can form and the cycle repeats, according to the DAA. Flares can last up to months without treatment for pustular psoriasis.
The different types of pustular psoriasis are defined by the area of the body where the pustules appear.
Palmoplantar pustular psoriasis
As the name suggests, palmoplantar pustular psoriasis usually affects the palms of the hands as well as the soles of the feet. Pustules often develop in the sweat ducts,6 which are more densely packed on the palms and soles than anywhere else on the body. As with other types of pustular psoriasis, the skin usually becomes irritated and inflamed before bursting into pustules. A scaly plaque usually forms several days after the pustules form, according to the National Organization for Rare Disorders (NORD). You may have a burning sensation in your hands and feet that makes it difficult to stand up or touch anything.