- Moderate psoriasis covers 3% to 10% of your body.
- Severe psoriasis covers more than 10% of your body.
Knowing that you have moderate or severe psoriasis helps your doctor decide on a treatment. However, it's not the only factor involved in choosing a treatment.
You may have moderate psoriasis that really bothers you and want to start on a strong treatment. Or you may have more severe psoriasis that you barely notice and want to start with a milder treatment.
Your doctor will also consider these factors when helping you choose a treatment:
- The type of psoriasis you have
- How much psoriasis affects your life
- Your health
- Treatment costs to you
Your doctor may use the Koo-Menter Psoriasis Instrument to help decide which treatment you need. This one-page tool asks questions to find out how much psoriasis is affecting your life.
Usually, doctors start with the mildest treatments. If the first treatment doesn't work, you'll move up to stronger and stronger treatments until you find one that clears or controls your psoriasis.
If you have very severe psoriasis, you may need to take more than one of these drugs at a time. Sometimes adding ultraviolet light or sunlight to a psoriasis pill, injection, or cream can help it work better.
Treatments for Moderate to Severe Psoriasis
Even though everyone with psoriasis is different, doctors have a few standard treatments that they try in people with moderate to severe psoriasis. These include:
- Light therapy (phototherapy)
- Medications that suppress your immune system or target specific immune responses linked to psoriasis.
Light Therapy (Phototherapy)
Your dermatologist may have told you to stay out of the sun to prevent skin cancer and aging. But in people with psoriasis, the sun's ultraviolet A and B (UVA and UVB) rays can actually help clear the skin.
Some doctors recommend sitting outside in the sun for a few minutes a day. Or you can try an indoor light therapy that simulates UVA or UVB rays.
Here are three types of light therapy for psoriasis.
1. Ultraviolet B (UVB) Therapy
How it works: Your body is exposed to UVB light from a light box in a doctor's office or at home. The UVB light goes into your skin and slows skin cell growth.
Types of UVB therapy:
- Broadband UVB therapy -- releases a wide band of ultraviolet light
- Narrow-band UVB therapy -- releases a narrow band of ultraviolet light to target small areas of the skin
- Goeckerman therapy -- you apply coal tar to the skin before being exposed to UVB light. (This is infrequently used and only available at a few centers)
2. PUVA Therapy (Photochemotherapy)
What it is: You use a medicine called psoralen, which makes your skin more sensitive to light. Then you are exposed to ultraviolet A (UVA) light.
How it works: Psoralen is either applied to your skin or you take it by mouth. Thirty minutes to two hours later, your skin is exposed to ultraviolet A light. The light slows skin cell growth.
Side effects can include nausea (from oral psoralens), itching, redness, burns, blisters, freckles or aged skin, cataracts if you don’t wear sunglasses, and a higher risk for skin cancer, including melanoma.
3. Laser Treatment
What it is: A form of light therapy that uses lasers.
How it works: A thin beam of light targets psoriasis without affecting nearby skin.
- Excimer laser -- releases a focused, high-intensity beam of ultraviolet light
- Pulsed dye laser -- destroys the tiny blood vessels that support the formation of psoriasis plaques
Side effects can include redness, blistering, bruising, or scarring.
Medications for Moderate to Severe Psoriasis
Medications that you take by pill or injection affect the whole body. Your doctor may recommend one of these types of drugs if you haven't responded to topical creams or light therapy.
What it is: Cyclosporine (Neoral) is a drug that has been used to prevent organ rejection in transplant patients. It is also approved for treating psoriasis.
How it works: It suppresses the immune system and slows the growth of certain immune cells. Cyclosporine is given by capsule or liquid.
Side effects can include flu-like symptoms, headache, high blood pressure, higher cholesterol, sensitive skin, tingling in the arms or legs, upset stomach, fatigue, kidney damage, excess hair growth, and an increased risk for cancer.
What it is: A drug that was first used to treat cancer.
How it works: Methotrexate slows the rate of skin cell growth. Methotrexate can be given by pill, liquid, or injection.
Side effects can include nausea, vomiting, fatigue, headache, lightheadedness, easy bruising and bleeding, fever, mouth ulcers, trouble sleeping, sensitivity to sunlight, hair loss, and liver damage.
3. Biologic Treatments
What it is: Biologic drugs target the immune response that causes inflammation.
How it works: Biologics block immune cells that are involved in psoriasis. These drugs are given by a shot or by an IV infusion.
Biologic drugs include:
- Ixekizumab (Taltz) and secukinumab (Cosentyx). These are antibodies that bind to interleukin-17A, a protein that is involved in inflammation.
- Guselkumab (Tremfya). This medication selectively blocks interleukin-23 (IL-23) and is given by injection.
- Tumor necrosis factor-alpha blockers, including adalimumab (Humira), etanercept (Enbrel), and infliximab (Remicade). These drugs block a chemical messenger of the immune system called TNF-alpha. People with psoriasis have too much of this substance, which causes inflammation.
- Ustekinumab (Stelara). This drug blocks cytokines in the body called interleukin-12 and interleukin-23, which are thought to promote the increased growth rate of skin cells and inflammation from psoriasis.
Side effects can include swelling or rash at the injection site, increased risk for infections, including tuberculosis, and cancers such as lymphoma and nonmelanoma skin cancer.
You will need to be screened for tuberculosis while taking a biologic drug. You will also need to have regular blood tests to check your number of immune blood cells.
4. Vitamin A Derivatives
What it is: A man-made form of vitamin A.
How it works: These drugs help control how fast skin cells multiply. They are given by pill.
There are two types of vitamin A:
- Acitretin (Soriatane)
- Isotretinoin (Absorica, Amnesteem, Claravis, Myorisan, Zenatane, formerly called Accutane)
Side effects can include hair loss; thin nails; dry mouth, eyes, and skin; bleeding gums; nosebleeds; headache; joint or muscle pain; increased levels of fat in the blood; and sensitivity to sunlight.
Women who are pregnant or planning on becoming pregnant should not use these drugs due to serious birth defect risks.
5. Apremilast (Otezla)
How it works: Apremilast is an inhibitor of phosphodiesterase-4 (PDE-4), which controls inflammation within a cell.
Side effects include diarrhea, nausea and headache. These side effects may stop with continued treatment. In studies, a small number of people stopped taking Apremilast because of an adverse reaction. Some participants also had unexplained weight loss. It's recommended that those taking the drug have their weight monitored regularly and be monitored for depression.
6. Other Immunosuppressives
There are a few drugs that slow down the immune response and may be used in selected cases, but are used “off-label” (They are not FDA approved for psoriasis or psoriatic arthritis). They include azathioprine, hydroxyurea, and 6-thioguanine.