Psoriasis is not contagious and cannot spread between people. It can, however, spread from one area of the body to another, especially if it is left untreated.
Psoriasis is a common immune system disease that affects the skin. It can be painful and embarrassing, and people with psoriasis may find that others treat them differently during a flare-up.
Fast facts on psoriasis:
- Research suggests that some people develop psoriasis because of a genetic predisposition.
- Scratching itchy psoriasis does not cause psoriasis to spread.
- Psoriasis is not curable, but it is treatable.
Does psoriasis spread?
People who have never seen psoriasis before may assume that it is infectious. However, psoriasis is not a contagious disease, and the scaly patches it causes will not spread to another person.
However, psoriasis often spreads from one location to another.
This is not because the damaged skin infects other parts of the body but because the immune system process that causes psoriasis can get worse.
Depending on the type of psoriasis a person has, a psoriasis rash can develop in a variety of places on the body. Most people with psoriasis have plaque psoriasis. Plaque psoriasis often spreads to the outer elbows, knees, and scalp, though it can spread anywhere.
A severe form of psoriasis called erythrodermic psoriasis spreads over much of the body, causing bright red patches. This type of psoriasis is rare and can be life-threatening, so people experiencing psoriasis that spreads rapidly and is very red should see a doctor immediately.
Some people that have one type of psoriasis may also develop a different kind of psoriasis, such as inverse psoriasis. Inverse psoriasis often shows up in skin folds, such as in the armpits.
People who have a genetic risk for psoriasis might develop their first outbreak after coming into contact with a trigger. This means that a person's psoriasis is caused by an interaction between their genes, immune system, and environment.
Some common triggers for psoriasis outbreaks include:
- skin injuries, including vaccines and sunburns
- infections, including both skin and other infections
- some medications, including lithium, drugs used to treat malaria, some heart and blood pressure medications, and a non-steroidal anti-inflammatory drug called Indomethacin.
Most people experience psoriasis in the form of flare-ups. A psoriasis flare may begin as a small patch that spreads, then gradually gets better. Most flare-ups are triggered by something.
Scratching a psoriasis rash does not cause it to spread from one location to another. However, it may slow the healing process, creating the appearance that psoriasis is spreading.
Treating psoriasis is the best strategy for preventing it from spreading. Treatment often involves a process of trial and error. What works for one person might not work for another, and a person's treatment needs may change over time.
Some treatment options include:
It is essential to moisturize the skin because it can speed the healing process and prevent itching. A range of moisturizing lotions that are suitable for psoriasis are available without a prescription.
Tar shampoo and soap may also help. Ingredients that encourage old skin cells to fall off, such as salicylic acid, can reduce the appearance of flaky plaques. However, some of these products can be harsh on the skin, so getting advice from a professional can help determine the most suitable lotion.
Steroid creams, such as hydrocortisone, are also safe and effective for most people. They help with itching and can speed healing. Using steroid creams for a very long time may cause side effects, however, so talk to a doctor about the safe use of steroids.
A wide range of prescription medications can help with psoriasis. Topical steroid creams that are stronger than those available over-the-counter may help. Some other options include:
- antibiotics when psoriasis plaques become infected
- systemic drugs, such as methotrexate and cyclosporine
- biologic medications, which are immune system drugs given through an injection or intravenously (IV)
- new treatments, such as apremilast, that target specific parts of immune cells
Phototherapy is a light therapy that involves exposing skin to UVB light. In the first instance, a person will need to go to a clinic or doctor's surgery for the treatment, but many people choose to continue the therapy at home. It is essential to use the correct equipment, which will require a prescription and to get regular medical checkups.
Some people find their psoriasis improves after spending time in the sun and many doctors recommend that people expose their skin to the sun. Do this for a short time at first and increase exposure time slowly. Never use sunbeds or tanning lamps, as these can increase the risk of developing melanoma by 59 percent.
Identifying and avoiding psoriasis triggers can prevent the immune system from overreacting and causing a psoriasis flare-up. When psoriasis appears, minimizing exposure to triggers can stop it from spreading.
Complementary and alternative remedies
Some people use complementary and alternative remedies, such as acupuncture, to prevent psoriasis from spreading. Other strategies, such as meditation and therapy, may help some people cope with the emotional effects and social stigma of having psoriasis.
Psoriasis is more likely to spread and become severe when it is left untreated. So treatment from a doctor who specializes in psoriasis can significantly reduce the risk that psoriasis will spread, or that the next flare-up will be worse than the last.
A family history of psoriasis, having another immune system disorder, smoking, trauma to the skin, and exposure to many psoriasis triggers are additional risk factors that might cause psoriasis to spread.
Although there is some evidence that specific environmental factors might trigger psoriasis, those factors vary from between patients. This makes it almost impossible to prevent psoriasis developing for the first time. However, it might be possible to prevent subsequent flare-ups by keeping track of triggers.
A person with psoriasis might find that their psoriasis gets worse with stress, after sunburn, or when they eat certain foods. Avoiding these triggers can lengthen the time between flare-ups, and may prevent an early flare-up from spreading.
There is no cure for psoriasis. Most people can control their symptoms with medication and lifestyle changes, though psoriasis flare-ups may continue. Following the treatment plan recommended by a doctor can increase the time between flare-ups and prevent the disease from spreading.
Some people with psoriasis may feel stigmatized and embarrassed, particularly when people they know mistakenly believe that psoriasis is contagious. Psoriasis will not spread to another person, and touching a psoriasis plaque will not cause it to spread elsewhere.
Psoriasis is, however, a disease that tends to spread on a person's body. People who think they might have psoriasis should talk to a doctor about controlling symptoms. Keeping a journal of lifestyle factors and triggers may also help since it can make it easier to identify what makes psoriasis better or worse.