About psoriasis

For you or a loved one with psoriasis, this section goes into the medical treatment methods and alternative therapies available. Perhaps most importantly, though, it emphasizes the importance of a support network and empowers people with practical things they can do to make it easier to live with the condition.

What is psoriasis?

Normal skin cells grow, mature and are shed in a 28- to 30-day cycle. Psoriasis is a disease that causes the skin cells to grow too quickly. This means skin cells are not shed normally and the cells pile up creating lesions (plaques). These lesions are dry or red areas of skin that are often covered with silvery-white scales. Sometimes the lesions itch, burn, or bleed. Patches are most often seen on the elbows, knees, and torso, but can appear anywhere, including the scalp. Fingernails and toenails can also be affected — nails become thickened, pitted or ridged.

Psoriasis is a chronic disease, meaning once it starts, it likely persists life-long. We don’t yet know how to cure it, but we do know about the types of psoriasis symptoms, how to treat symptoms, and how the disease progresses.

What causes psoriasis?

Psoriasis is not contagious — you can’t catch it from someone who has it. The lesions you see on your skin are the result of an overactive immune system which mistakenly attacks your own healthy skin cells. Scientists are not sure why this happens. But the nature of psoriasis puts it in the category of “autoimmune diseases”.

Scientists are studying the potential causes:

  • Genetics: some people have genes that set them up to develop psoriasis — although carrying these genes is enough to develop the disease
  • Triggering event: external factors are usually needed to set off psoriasis
  • Triggers are not universal, but there are some that are common to many people:
    • Stress
    • Damage or injury to the skin, like scratches, scrapes, bug bites, cuts, sunburns and vaccinations
    • Use of certain medications, or certain infections
    • Smoking
    • Heavy alcohol consumption
    • Cold weather
  • Other risk factors: someone who smokes, is overweight, or has a relative with psoriasis is also at higher risk of developing the disease

Are there other associated conditions?

Though it affects the skin, psoriasis is an inflammatory disease, which means people with the condition have irregularities in their immune system. Immune system issues can increase the risk of other inflammatory diseases – consequently there are several conditions associated with psoriasis including:

  • Psoriatic arthritis (PsA): PsA causes swelling, pain and warmth (inflammation) in the joints as well as back and neck pain. About a third of people with psoriasis also develop PsA. PsA tends to occur about 5 to 10 years after a psoriasis diagnosis.
  • Cardiovascular disease (CVD): Scientists now know that there is a strong association between cardiovascular disease and psoriasis. People with psoriasis, especially those with severe psoriasis, are more likely to develop CVD, including heart attacks, compared to people without psoriasis.
  • Metabolic syndrome: Metabolic syndrome is a group of conditions that include heart disease, abdominal obesity and high blood pressure. People with psoriasis are more likely to have metabolic syndrome than the average person. The risk of developing metabolic syndrome is higher for people with more severe psoriasis.
  • Obesity: People with psoriasis are more likely to be obese compared to people without psoriasis. Scientists have found that losing weight can help reduce psoriasis symptoms.
  • Type 2 diabetes: Like psoriasis, diabetes is associated with whole-body inflammation. People with psoriasis (including both mild and severe forms) are more likely to have type 2 diabetes compared to people without psoriasis.
  • Depression and anxiety: People with psoriasis are more likely to suffer from depression or anxiety compared to the average person. Depression is a medical condition that causes a prolonged feeling of sadness or hopelessness that can cause eating or sleeping difficulties and loss of interest in activities the person once enjoyed. People with anxiety persistently worry and are often unable to relax.
  • Cancer (malignancy): Studies have shown that people with psoriasis have a higher risk of developing certain types of cancer such as lymphoma. People who have had psoriasis for many years may be at higher risk of developing colon, bladder and kidney cancer.
  • Inflammatory bowel disease (IBD) including Crohn’s disease: IBD is a general term for diseases than involve inflammation of the digestive tract. Among people with psoriasis, the risk of IBD is 4 times higher than in healthy people. Types of IBD include Crohn’s disease and ulcerative colitis. Both conditions generally involve severe diarrhea, abdominal pain, fatigue and weight loss.
  • Liver disease: People with psoriasis may have a higher risk of developing a liver problem called nonalcoholic fatty liver disease (NAFLD). In people with both psoriasis and diabetes, the risk of developing NAFLD is higher. NAFLD includes a range of liver conditions affecting people who drink little or no alcohol. People with NAFLD store too much fat in their liver cells sometimes due to conditions such as obesity, prediabetes and diabetes.
  • Chronic kidney disease: The kidney filters excess fluids and waste and excretes them in the urine. Chronic kidney disease means the gradual loss of this kidney function. According to a study done in the UK, people with severe psoriasis are 2 times as likely to develop chronic kidney disease compared to people with mild or no psoriasis.
  • Osteoporosis: Osteoporosis causes your bones to become brittle and weakened which can lead to a higher risk of fracture especially of the hip, wrist or spine. People with psoriasis are at higher risk of developing osteoporosis. The risk increases with longer duration of psoriasis.
  • Uveitis: Uveitis is a type of eye inflammation. Symptoms include eye redness, pain and blurred vision. People with psoriasis, especially men and those who develop the disease later, are at risk of developing uveitis.

If you are living with any of these associated conditions, your dermatologist or doctor may refer you to other specialists such as rheumatologists, oncologists, psychiatrists, gastroenterologists, etc., for the help they can give you with their respective expertise.

Fast facts

  • Psoriasis is a common inflammatory skin disease.1
  • Psoriasis affects more than 1 million Canadians.1
  • Psoriasis affects men and women equally.1
  • Psoriasis can occur in children and adults at any age but usually it begins between the ages of 15 and 35.1,2
  • Psoriasis affects people of both sexes, and of all races and ethnic groups.2
  • Family history of psoriasis is one of the most important risk factors for this disease.1
  • About 60% of patients with psoriasis say that it is a problem in their daily life.2

What are the effects of psoriasis?

Inflammation is a natural process that your body normally uses to protect itself from harm. Inflammation is behind the pain and swelling you feel from:

  • Bumping your knee
  • An infection in your throat
  • Burning your hand while cooking
  • A sunburn
  • A paper cut
  • Etc.

When a portion of skin is affected, it becomes red, swollen and painful, and feels hot or warm to the touch: this is called inflammation.

A normal skin cell takes 28 to 30 days to form at the bottom layer of your skin, then makes its way to the surface, falling off without you noticing. When your immune system malfunctions and produces inflammation in an area of your skin, it only takes three to four days for the skin cells to mature and reach the surface. The skin cells don’t have time to fall off, and build up with other skin cells instead, creating inflamed skin scales and skin plaques.

The severity of psoriasis is measured by the percentage of body surface affected (BSA). Your palm is usually the reference point to represent 1% of the total body surface. Mild psoriasis: less than 3% BSA Moderate psoriasis: 3 to 10% BSA Severe psoriasis: more than 10% BSA

Another aspect that can be measured is how psoriasis affects your quality of life. For example, even a mild case affecting only a small area in the palms or soles of the feet can have a significant impact on your life. Take this questionnaire to assess how psoriasis affects your quality of life and talk to your doctor.

Psoriasis symptoms tend to change over time, appearing differently in each person. People with psoriasis often suffer from a cycle of periods of active disease — flares — followed by periods when symptoms disappear, called remissions. The triggers, which can set off psoriasis in the first place, often worsen symptoms or cause a flare after a period of remission.

If inflammation from psoriasis is left untreated, it can eventually lead to thickened skin, scarring, disfigurement and bacterial skin infections caused by scratching and touching plaques. Fortunately, there are many ways to treat psoriasis and prevent complications before they happen.

Which body parts are affected?


Psoriasis patches can range from a few pinhead-sized spots to major eruptions that cover large areas of the body.

Are there other complications?

If you have psoriasis, you’re at greater risk of developing other diseases, such as:

  • Psoriatic arthritis. For more information about PSA, click here.
  • Cardiovascular disease
  • Metabolic syndrome
  • Obesity
  • Type 2 diabetes
  • Depression and anxiety
  • Cancer
  • IBD (including Crohn’s disease)
  • Liver disease
  • Chronic kidney disease
  • Osteoporosis
  • Uveitis

Many psoriasis patients also suffer from lack of self-esteem and sexual dysfunction.

Support means everything


No man is an island: in other words, it is not helpful to try to live with psoriasis by yourself. Your friends and family can help, along with your treatment team of health care professionals.

Living with any chronic disease can make you feel isolated and sad; especially when you have to adapt or change your daily routine, see many health care practitioners, and learn medical terms. But you don’t need to do it alone.

When you’re living with psoriasis, it’s invaluable to keep the lines of communication open with your family, friends and coworkers: they can’t understand what it’s like to live with psoriasis if you don’t talk openly about it.

Here are some tips and helpful insights we’ve learned from psoriasis patients:

  • Ask those closest to you to learn about your condition. This way they’ll understand your symptoms, or even go with you to your appointments. They can read this or other web sites, or consult reliable sources like libraries, or refer to our resources section.
  • Let them know you need their support. This could be just a sympathetic ear when you need to talk. Be sure to tell them that inflammatory diseases always have good and bad days.
  • Always be open and honest about your psoriasis. It’s the only way people can help you. Remember, if you’ve ever said to a friend or family member, “You don’t know what it’s like”, that’s maybe because you haven’t told them.

When we stop doing the things we love, our mood drops, symptoms seem worse, and it becomes even harder to get motivated. Keeping fun in your life is absolutely essential — make it a top priority. It boosts your mood, your relationships, and your energy level. Find one activity you love — even a small one — that you can add to each week without fail, and one you can add to each day. Once they become routine, you'll start feeling better and will want to add more.

Psoriasis is different for every patient, and treatment must be tailored for each individual case. The key is to communicate regularly with your doctor about your progress and the effects of your treatment, and to follow your treatment instructions every day, as medication can take time to work. If you feel there’s a problem with your regimen, or are experiencing any side effects, talk to your doctor right away about trying alternative methods. Don't hesitate to ask questions and get involved in decision-making regarding your health. And keep in mind there are many options available to you, so if one approach isn’t working, another one might.

There are independent patient associations and organizations that may be able to help you learn more

Learn more

Lifestyle options

Lifestyle options

If you have psoriasis, there are things you can do; soothing skin care routines, healthy eating and relaxation techniques are important factors in keeping your skin healthy. Talk to your health care professional for more guidance. While there’s no cure yet for psoriasis, a healthy lifestyle certainly supports overall health.

Proper skincare will help you manage some psoriasis symptoms. To soothe your skin:

  • Soak up a little sun: Small amounts of natural sunlight have been found to help psoriasis symptoms in some people. To be sure that sunlight is a good option for you, talk to your doctor first. Too much sun can trigger or worsen flares or increase the risk of skin cancer.
  • Control air humidity: use a humidifier to increase the moisture level in the air of your home.
  • Moisturize: keep your skin moist with fragrance-free heavy creams and ointments that lock water into the skin. When the weather is cold and dry, apply a moisturizer several times a day.
  • Prevent injuries to your skin: Do not scratch or pick at your skin. An injury to the skin can lead to a flare. Trim your nails regularly and avoid any clothing or jewelry that can irritate your skin.
  • Avoid irritating skin products: don’t use strong soaps and moisturizers that contain perfumes or chemicals. Use creams that do not contain alcohol since it can dry out your skin.
  • Take daily baths: gently washing your skin every day helps to remove dead skin and calm inflammation. The water should be warm - not hot. After the bath, pat your skin dry and apply ointment-based moisturizer or oils while the skin is still moist – this prevents the water from evaporating from your skin.
  • Use medicated creams and ointments: your pharmacy has non-prescription products such as salicylic acid (a peeling agent) to help soften and remove scales and coal tar that can help reduce inflammation, itching and scaling. For scalp psoriasis, try a medicated shampoo. Always talk to your doctor before using any non-prescription products and follow label directions.
  • Quit smoking
  • Maintain a healthy weight: If you are overweight, losing weight can help reduce folds of skin on your body. Psoriasis can appear in these folds of skin.

If you have psoriasis, maintaining a healthy weight is the main reason to exercise and watch what you eat. It helps reduce the severity of your psoriasis, and can minimize your risk of developing related conditions like diabetes and heart disease. Furthermore, a healthy weight can help protect joints from PsA which occurs in about 1 in 7 people with psoriasis.

First identify the triggers that bring about your flares or make your symptoms worse, and then try to avoid them. For example:

  • Infections (including strep throat or skin infections): try to avoid them and if you do get an infection, treat it as soon as possible.
  • Avoid alcohol. It’s a potential trigger, and may decrease the effectiveness of some psoriasis treatments.
  • Choose not to smoke.
  • Stress: find ways to manage stress such as yoga, meditation and support groups. If you find yourself feeling stressed, take a deep breath, hold it and then breathe out slowly.
  • Injuries to the skin (for example, a bug bite, severe sunburn, scrape or cut): Opt out of activities or situations that could injure your skin. If injuries happen, treat them quickly. If the injury becomes itchy, take action to calm the itch.
  • Cold dry weather (and drying heat): apply moisturizer throughout the day and use a humidifier. Dress warmly when you go out in the cold and stay away from direct sources of heat such as a fireplace.
  • Scratching your skin is a trigger, keep your nails short and never scratch.
  • Keep a food diary. While science hasn’t proven that certain foods either improve or aggravate psoriasis, you can track whether certain foods affect your symptoms
  • Avoid staying in the sun for prolonged periods to prevent sunburns, use sunscreen.
  • Certain medications: talk to your doctor if you think one of your medications is a trigger for your psoriasis.

Stress can lead to an increase in blood pressure, interrupt sleep, and play a role in the intensity of psoriasis symptoms. The first step is identifying stress triggers — then developing relaxation and coping skills to improve your overall wellbeing and give you a greater sense of control over your psoriasis.

On days when you might feel particularly self-conscious about the appearance of your skin, you can cover the affected areas with clothing, or use makeup or concealer to mask redness and plaques. However, never cover open sores or unhealed lesions — it could irritate your skin even more.

Complementary therapy options

For some people with psoriasis, complementary and alternative therapies — treatments that fall outside the scope of traditional western medicine — are an option that can be considered. Ask your health care professional about alternative therapies.

Omega-3 fatty acids (fish oil) supplements may reduce inflammation associated with psoriasis. Talk to your health care professional for more guidance before taking any supplements.

Some people add natural relief therapies to their medical psoriasis treatments, such as acupuncture, acupressure, massage therapy, or biofeedback (with or without hypnosis). Always first discuss these treatment options with your physician, and be sure to tell any alternative health specialist about your condition in order to avoid injury.

Medical treatment

Psoriasis medications relieve symptoms and inflammation, and interrupt the cycle of increased production of skin cells. Your doctor can explain the different medications, their benefits and side effects. You will likely try different therapies or combinations before finding the best prolonged symptom relief.

Topical Corticosteroids: Applied directly to the affected area, topical corticosteroids are the most frequently prescribed for treating mild-to-moderate psoriasis. They slow cell turnover, which reduces inflammation and relieves itching. They should only be used for limited periods, because long-term use or overuse of strong corticosteroids can cause thinning of the skin and resistance to the treatment's benefits.

Vitamin D analogues: Your doctor may prescribe an ointment containing a form of Vitamin D called calcipotriol which has been shown to help treat psoriasis symptoms.

Topical Retinoids: These vitamin A derivatives are believed to normalize DNA activity in skin cells. The most commonly occurring side effect is skin irritation. Using it topically also increases the skin’s sensitivity to sunlight. It is important to ensure skin is protected from the sun.

Other topical options can include calcineurin inhibitors, anthralin and coal tar.

Brief exposure to small amounts of sunlight, or to controlled doses of UVB light from an artificial source, may improve mild-to-moderate psoriasis symptoms. Short-term side effects such as redness, itching and dry skin may occur. Moisturizers help lessen these side effects.

Combining UVB with other therapies may increase efficacy dramatically and allow for lower doses of medication.

Reserved for moderate-to-severe cases, PUVA (psoralen plus long-wave ultraviolet A light) can be used to clear psoriasis. PUVA uses a light-sensitive compound in addition to light therapy, and usually works in over 85% of people with chronic psoriasis lesions.

The short-term side effects with PUVA include nausea, headache, burning and itching. The long-term side effects can include dry and wrinkled skin, freckles, and increased risk of skin cancer (including melanoma, the most serious form of skin cancer).

If your psoriasis is severe and doesn't respond to other treatments, your doctor may recommend using oral retinoids.

Related to vitamin A, oral retinoids may help reduce the production of skin cells in severe psoriasis that does not respond to other therapies. Signs and symptoms of psoriasis usually come back once therapy is stopped.

It’s not known exactly how retinoids work, but they reduce skin cell production and the speed at which they grow and shed.

Common side effects of retinoids are dry skin and mucous membranes, itching, and hair loss. Women must avoid pregnancy for at least three years after taking retinoids as they persist for long periods in the body and can cause severe birth defects.

Oral cyclosporine suppresses the immune system and has a level of effectiveness similar to methotrexate but can only be taken on the short term. Like other immunosuppressant drugs, cyclosporine can increase your risk of infection and other health problems, such as cancer.

Oral methotrexate helps treat psoriasis by decreasing the production of skin cells and suppressing inflammation. Methotrexate is generally well tolerated in low doses, but may cause side effects such as upset stomach, loss of appetite and fatigue. When used for long periods, it can cause some serious side effects, including liver damage and decreased production of red and white blood cells and platelets.

Hydroxyurea and thioguanine are almost as effective as cyclosporine and methotrexate. However, these medications are less potent and have fewer side effects. Both can lead to anemia and cannot be taken by pregnant women due to the risk of birth defects.

Biologic response modifiers, or biologics for short, are medications specifically designed to target your body’s immune system. Biologics are used to slow the production of skin cells, and ease the pain and swelling of psoriasis plaques and scales.

Biologics can take some time to work. Some people notice the effects of the medication quickly (at 2 weeks), while it takes others months to feel the effects. Biologics are used for moderate-to-severe cases. They are prescribed when other psoriasis therapies aren’t effective.

Common side effects with biologics include mild skin reactions at the injection site, nausea, abdominal pain and headaches. Rarely, people who take biologics may develop serious infections, lupus-like reactions, nervous system diseases, and cancer. You should not start a biologic if you have a severe infection. Certain biologics should not be taken by patients with moderate to severe congestive heart failure, a history of multiple sclerosis or cancer. Inform your doctor if you have a history of tuberculosis, hepatitis B, recurrent infections, require vaccination or if you are pregnant or could become pregnant.

Biologics are administered in two ways: infusion or injection. Your doctor can provide you with information and help make the right choice for you.

Biologics that are used to treat moderate to severe psoriasis in Canada are categorized based on how they work:

  • TNF inhibitors: block the action of tumour necrosis factor (TNF) made by the immune system. People with psoriasis may have too much TNF in their body. This extra TNF can cause skin inflammation.
  • Interleukin inhibitors: act on specific proteins (called interleukins) and prevent them from causing the body’s immune system to attack the skin and nails. Interleukin inhibitors neutralize the activities of specific proteins present at increased levels in psoriasis.


Biologics are special medications created using the biologic processes within living cells.

When the patent on a biologic medication expires, other companies are allowed to make copies. However, since it is impossible to make exact copies of biologic medications because of the way they are made, the copies are not called generics or even biogenerics. The correct term is biosimilar since it can only be similar and not identical to the original.

Biosimilars are similar to, but not identical to the original biologic drug. This is because the group of cells used to produce the drugs (the cell line), the actual drug molecule and the manufacturing process are different.

In Canada, manufacturers of biosimilars are required to show Health Canada that their product is similar to the original biologic and that the benefits of their product outweigh the risks.

Since an original biologic and its biosimilar version are not identical, it’s important that you review your prescription with your doctor so you know which one is being prescribed.

For more information about biosimilar medicines, visit:

Health Canada

Alliance for Safe Biologic Medicines (USA)


Please note that the information on this Web site should not be used as a substitute for seeking medical advice or treatment from a physician. You should not use this information to diagnose or treat a medical condition or health problem. Speak to your health care provider if you have any questions about your medical condition, symptoms or treatment options. The information found on this Web site can be referenced at



The Canadian Psoriasis Network

The mission of the Canadian Psoriasis Network is to enhance the quality of life of people living with psoriasis and psoriatic arthritis by providing current information on research and treatment options and by working with others to build awareness and advocacy about the complexities of these conditions.

The Canadian Association of Psoriasis Patients (CAPP)

Web site for the Canadian Association of Psoriasis Patients (CAPP), whose goal is to get this challenging and misunderstood skin condition out in the open, help all patients manage their lives with psoriasis, and to make sure every Canadian can access the treatment they need.

The Canadian Dermatology Association (CDA)

This is the Canadian Dermatology Association (CDA) website, representing Canadian dermatologists. The CDA helps advance the science of dermatology, educates and informs dermatologists, supports patient care, provides public education on sun protection and other aspects of skin health and generally promotes ways to achieve healthy skin, hair and nails.

The National Psoriasis Foundation (NPF)

The National Psoriasis Foundation (NPF) is a non-profit organization in the USA dedicated to finding a cure for psoriasis and psoriatic arthritis and eliminating their devastating effects by promoting research, advocacy and education.

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