context: Pustular psoriasis is a skin disease. You'll see white bumps filled with pus near or inside red skin blotches. These are called pustules, and they can hurt and be scaly, flaky, or itchy. It's most likely to affect: The palms of your hands The soles of your feet Your fingers and toes Even though you see pus on your bumps, it's not an infection. You can't catch pustular psoriasis from someone else or give it to others. Pustular psoriasis usually happens to adults -- it's rare for kids to have it. It can run in families. You can get pustular psoriasis either on its own or with another kind of psoriasis called plaque psoriasis. Pustular psoriasis. Note the clearly defined, raised bumps on the skin that are filled with pus (pustules). The skin under and around these bumps is red. There are three types of pustular psoriasis, based on where the blister outbreaks are or how fast they popped up. Palmoplantar pustulosis ( PPP): Blisters form on small areas of your body, usually your palms or the soles of your feet. These pus-filled spots can turn brown, peel off, or crust over. Your skin can crack, too. This type of psoriasis may come and go. People who smoke are more likely to get this form. Acropustulosis: Small, very painful lesions pop up on your fingertips or toes. The pain can make it hard to use your fingers or toes. In rare cases, it can cause nail or even bone damage. Generalized or Von Zumbusch: Red, painful, tender skin blotches show up over a wide area of your body, and pus-filled blisters pop up soon after. Your skin may be very itchy. You also might be very tired or have fever, chills, dehydration, nausea, weak muscles, headache, joint pain, a fast pulse, or weight loss. This is a rare, serious disease -- see your doctor right away if you have these symptoms. Psoriasis is an autoimmune disease. Your immune system usually sends white blood cells to fight off disease in your body. But in this case, they attack your own skin by mistake. A few things can trigger psoriasis flares: Medications, such as steroids Something that irritates your skin, like a topical cream or harsh skin care product Too much sunlight Stress Pregnancy Infection Hormones A mutation, or change, in one of two specific genes ( IL36 RN or CARD14), may make you more likely to get pustular psoriasis. If you have one of these gene mutations, one of those triggers could set off a flare. You'll see a dermatologist (skin doctor) who will ask about your symptoms, your medical history, and any family history of psoriasis. She may need to take a small sample of your inflamed skin to look at under a microscope. That's called a biopsy. If you have a severe flare, she may also test your blood for signs of high white cell counts; signs that your kidney and liver are working the way they should; and whether you have healthy levels of electrolytes, calcium, and phosphate. The goal of treatment is to ease your symptoms and control outbreaks. What you take may depend on your type of pustular psoriasis. Small, local outbreak: Your doctor may try a topical steroid cream first to treat the sores. Coal tar or salicylic acid creams can help with scaly skin. You'll slather on lotions to soothe and prevent cracked skin. Then you'll slip on cotton gloves or socks to hold the moisture in. PPP and acropustulosis outbreaks can be stubborn. Your doctor may try ultraviolet light treatments on the inflamed skin. This is called phototherapy. Oral drugs like methotrexate or cyclosporine may help calm down your immune system. Acitretin ( Soriatane) is another drug that can slow skin outbreaks. It's a retinoid, or a synthetic form of vitamin A. All these drugs can have serious side effects, so you may need to switch treatments from time to time. If you smoke, try to quit. Smoking makes your psoriasis harder to treat. Widespread outbreak: If you have generalized or Von Zumbusch psoriasis, get medical care right away. You'll need fluids, along with treatments to prevent infection, ease your fever, and calm inflamed, broken skin. While you're in the hospital, you need to rest, stay hydrated, and keep cool. Your doctor may try acitretin, methotrexate, cyclosporine, steroids, or biologics (drugs made from living cells) like etanercept or infliximab to get your flare under control. Once your skin redness and pustule outbreaks have calmed down, you can also try PUVA, where you take a drug called psoralen and then beam ultraviolet light at the affected area of your skin. Sometimes, one treatment doesn't do the trick. You may need to combine one or more to feel better.