Psoriasis is an inflammatory condition that affects the skin and sometimes the joints. It occurs due to a problem with the immune system that results in an overgrowth of skin cells, leading to skin changes.
The pus consists of white blood cells and is not a sign of infection. On light skin, the affected areas will appear red. On darker skin, the patches are darker in color.
Generalized pustular psoriasis (GPP), or von Zumbusch psoriasis, causes widespread symptoms across the body.
Other types of pustular psoriasis include palmoplantar pustulosis and acrodermatitis continua of Hallopeau, which affect only the hands and feet.
Pustular psoriasis can also occur during pregnancy.
Any pustular psoriasis will need medical attention. A combination of topical and other therapies can usually clear the symptoms. A person with GPP may need to spend time in the hospital, as it can be life-threatening.
Psoriasis is an inflammatory condition that occurs when the immune system changes the way cells work, leading to inflammation in different areas of the body. It can trigger the rapid growth of skin cells that results in skin changes.
Doctors do not know why this happens, but they think that specific genetic features might increase a person's risk of developing the condition. Pustular psoriasis appears to be hereditary, and it can run in families.
A person with these genetic features may be more likely to develop psoriasis after exposure to specific triggers, but not everyone with the features will develop it.
Factors that appear to trigger pustular psoriasis include:
- the use of or withdrawal from certain internal medications, including corticosteroids
- the use of some topical creams
- overexposure to UV light, for example, sunlight
- some infections
Pustular psoriasis is not contagious.
People with pustular psoriasis have a higher risk of developing other types of psoriasis and other conditions.
Around 1 in 10 people with pustular psoriasis have a previous history of plaque psoriasis.
Also, a person with any type of psoriasis may have a higher risk of developing:
- metabolic syndrome, which includes diabetes, high blood pressure, and cardiovascular disease
- some types of cancer
- other inflammatory conditions, such as rheumatoid arthritis
A person who notices symptoms of any type of psoriasis should see a doctor, who may also test blood sugar levels and carry out other tests.
Pustular psoriasis involves widespread areas of inflamed skin and pustules that contain fluid, or pus, which gives them their yellow or cream color. It can be painful.
Pustules that burst or dry up may appear brown or crusty. The red or darkened skin surrounding the pustules may be thick and flaky, and the skin may crack.
The presence of pus does not indicate an infection or bacteria. As with all types of psoriasis, the pustules are not contagious and do not pose a threat to others.
This can occur suddenly.
According to Dermnetz NZ, a person can expect the following to happen:
- First, the skin will become hot and tender.
- Within a few hours, pustules appear, around 2–3 millimeters in diameter.
- After around 24 hours, the pustules will start to join together so that pools of pus form.
- The areas of pus dry out, leaving a smooth, shiny surface.
- The cycle begins again, with new pustules appearing every few days to weeks.
- In time, with treatment, the symptoms will clear. However, another flare may occur at a later date.
Some people go on to develop erythroderma, a serious condition that may need emergency medical attention.
Symptoms may include:
- inflamed skin that is red on light skin or darker in black skin
- peeling skin all over the body
- fever and shivers
- intense itching
- a rapid pulse
- dehydration and exhaustion
- a headache
- muscle weakness and joint pain
- weight loss
The skin may be very sore and fragile. After an outbreak of GPP, milder flares of psoriasis may occur.
A person may also have:
- furrowed or geographic tongue
- unusual nail growth or poor nail formation
Large, yellow pustules occur in the fleshy areas of the hands and feet.
It can happen in the following stages:
- the skin becomes red
- pustules form
- scaling occurs, and the skin may crack
Depending on the severity, some people may find everyday tasks, such as walking, challenging.
According to the Psoriasis and Psoriatic Arthritis Alliance (PAPAA), around 5% of people with psoriasis will experience palmoplantar pustulosis.
According to PAPAA, it is most likely to affect people who:
- are aged 20–60 years
- have had an infection
- have experienced stress
Palmoplantar psoriasis is another type of psoriasis that can affect the hands and feet. Learn more here.
Acrodermatitis continua of Hallopeau
This is a rare form of pustular psoriasis that involves painful skin lesions on the ends of the fingers and sometimes the toes. The lesions typically form after an injury in the area. Bone changes may also occur.
Pustular psoriasis of pregnancy
A rare type of pustular psoriasis —
It can affect a person who has not had psoriasis before and usually resolves after pregnancy.
Women who are receiving treatment for psoriasis and become pregnant should see their doctor for guidance as they may need to adjust their medication. Some medications may have adverse effects during pregnancy and breastfeeding.
A dermatologist can usually identify pustular psoriasis by the type of lesions that appear on the skin, but tests can also confirm the diagnosis and identify possible complications.
A doctor may recommend:
- laboratory tests to rule out a bacterial infection
- a skin biopsy
- a blood count
- kidney and liver function tests
- measures of levels of electrolytes and minerals
Damage to the skin can result in a loss of fluid and internal damage. Depending on how severe symptoms are, a person may need to spend time in the hospital.
A doctor may prescribe:
- a topical steroid cream or emollients to apply to the affected area
- systemic medications to take by mouth or as an injection, such as methotrexate
- a biologic medication to help manage flares and symptoms
Treatment will vary from person to person depending on their symptoms. A person may need to try more than one treatment or a combination of therapies before finding a suitable one.
Topical therapies can help, either alone or combined with other options.
These may include:
- compresses containing suitable topical therapies
- corticosteroids to apply directly to the skin
- coal tar or salicylic acid to help with scaling
- emollients and moisturizers to help prevent cracking
Over-the-counter (OTC) topical creams containing salicylic acid or hydrocortisone may help some people, but individuals should check with a doctor before using them.
Other options include light therapy or oral medications.
GPP can affect large areas of the skin, and the person may need immediate medical attention.
Depending on how severe the symptoms are, they may need to spend time in the hospital.
Treatment will aim to:
- restore the skin's protective function and chemical balance
- prevent loss of fluid
- stabilize the body's temperature
Skin damage can result in fluid loss, and this can lead to dehydration and a chemical imbalance in the body. If this happens, it can put a strain on the heart and kidneys, especially in older adults.
Strategies will include:
- bed rest
- bland emollient therapy
- avoiding excessive heat
- removing all possible triggers, including any medications that may be causing the problem
Medications for GPP include:
- antibiotics for confirmed or suspected infection
- systemic corticosteroids
- biologic medications
A doctor may prescribe cyclosporine and colchicine off-label. Off-label means the medications have received approval for another condition, but the doctor knows that they can help with pustular psoriasis.
Pustular psoriasis can be challenging to treat.
Doctors often combine or rotate treatment, depending on how the symptoms respond and the possible side effects. Combining medications may help clear the skin and bring about remission.
For people who experience frequent flares or moderate to severe symptoms, a doctor may recommend using a biologic treatment.
This is a type of therapy that can reduce the risk of flares and the severity of symptoms. A doctor may give it as an injection or an infusion. Some types are suitable for a person to use at home.
Biologics can help resolve the underlying problem that leads to skin symptoms by targeting specific genes that affect how the immune system works.
Pustular psoriasis usually needs medical treatment, but some home remedies may offer additional relief by soothing the skin and relieving irritation and itching.
Possible options include:
- bathing with salt water
- taking oatmeal baths
- using an oil-rich moisturizer to keep the skin moist and possibly prevent peeling
If scales form, a person should remove them with a soft cloth.
Skin care is essential because blistering increases the risk that bacteria will enter the skin. Keeping the skin clean and moisturized can help reduce the risk of infection.
Learn more here about home remedies for psoriasis.
Prevention and outlook
Psoriasis is a long-term condition that affects the immune system. Most people will continue to experience flares, but medication and lifestyle options can help to reduce the risk and severity of symptoms.
It is not possible to prevent a condition that results from a genetic change, but some lifestyle choices may reduce the risk of pustular psoriasis occurring.
Tips that may help include:
- not smoking
- avoiding drinking unhealthful amounts of alcohol
- avoiding stress where possible
- getting enough sleep
- following a healthful diet
Click here to find out more about how diet can affect psoriasis.
Too much exposure to sunlight may trigger a flare or make symptoms worse, but studies also show that some sun exposure may benefit a person with psoriasis. An individual should ask their doctor about how much sun is good for them, and how to get the right amount of sunshine.
Learn more here about how sunshine can affect psoriasis.
A person should talk to their doctor about a treatment plan, follow the doctor's instructions, and inform the doctor if changes occur, if symptoms worsen, or if a medication appears to trigger adverse effects.
I sometimes have pustular psoriasis. Is there any diet I can follow that will help prevent a flare?
At this time, there are no known diets that can prevent a flare. However, there is evidence that a diet that promotes weight loss can help with the symptoms and frequency of flareups for psoriasis in general.
Try a diet that consists of less alcohol and fewer nightshade foods, such as tomatoes. Including fish oil and vitamin D to the diet might help some people manage their symptoms.Debra Sullivan, PhD, MSN, RN, CNE, COI Answers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.