Psoriasis Types, Causes & Triggers
Psoriasis is a chronic disease of the immune system that triggers skin cells to grow too quickly causing itchy skin spots, red patches, and thick flaky lesions. Many people who have psoriasis will suffer this medical condition for life. It is possible to see clearer skin by learning more about psoriasis and seeing a dermatologist regularly for treatment.
Despite its appearance, psoriasis is not contagious. People who get psoriasis tend to have a blood relative who has psoriasis, indicating a genetic link. For psoriasis to appear, a person must inherit the right mix of genes and be exposed to a trigger.
Common triggers can be stress, strep throat, and winter weather. Many people see their psoriasis flare up during the winter or a particularly stressful time. A scratch or bad sunburn can also be a trigger. For some people, psoriasis flares about 10 to 14 days after they injure their skin. Some medications can trigger psoriasis, including lithium, blood pressure medications, and some medications taken to prevent malaria.
What Are the Types of Psoriasis?
- Plaque Psoriasis: This type of psoriasis affects about 80% of psoriasis sufferers and causes patches of raised, reddish skin covered by silvery white scales. Patches frequently form on the elbows, knees, and lower back, but can appear anywhere on the skin.
- Scalp Psoriasis: Identical in appearance to plaque psoriasis on the body; it is characterized by silvery white scales and reddish patches. Scalp psoriasis also tends to be very itchy. Because patients often cannot help scratching and the scales fall onto a patient’s clothing, scalp psoriasis can be misdiagnosed as dandruff. Even with the right diagnosis, scalp psoriasis treatment can be difficult.
- Nail Psoriasis: Psoriasis can affect the fingernails and toenails. One sign of nail psoriasis is the appearance of tiny pits in the nails. As the psoriasis worsens, the nails may loosen, thicken, and eventually crumble. Sometimes nail psoriasis is misdiagnosed as a nail infection.
- Guttate Psoriasis: Usually occurs in children and young adults, causing small, red spots on the skin. This type of psoriasis often appears after a sore throat and frequently clears up by itself in weeks or a few months. Many people never have psoriasis again. If a person already has plaque psoriasis and guttate psoriasis develops, it often means that his or her psoriasis is worsening.
- Pustular Psoriasis: Usually appearing on the palms and soles of the feet, this type of psoriasis looks like white, pus-filled bumps surrounded by red skin. Pustular psoriasis also can develop all over the body. This causes a severe and sometimes life-threatening psoriasis that dermatologists call generalized pustular psoriasis.
- Inverse Psoriasis: With this type of psoriasis, painful red patches can appear in the folds of the skin, including the armpit, under the breasts, in the crease of the buttocks, and in the genital area.
- Erythrodermic Psoriasis: This least common type of psoriasis causes severe redness and shedding of the skin over a large portion of the body. The skin looks as if it has been burned. There is often severe itching and pain. Erythrodermic psoriasis can be life-threatening.
Some people who have psoriasis develop a type of arthritis called psoriatic arthritis. The first sign is frequently swollen, stiff, and sometimes painful joints when waking up. If you experience this, contact your dermatologist right away. Like psoriasis, psoriatic arthritis is a lifelong condition. If psoriatic arthritis worsens, the affected joints can deteriorate. Medication can help to prevent this. It is important to contact your dermatologist if you experience joint problems.
How Is Psoriasis Diagnosed?
Dermatologists diagnose psoriasis by examining the patient’s skin, nails, and scalp. To find out if anything else may have developed, such as an infection, a dermatologist may perform a biopsy during an office visit.
What Is the Best Treatment for Psoriasis?
While there is no cure for psoriasis, treatment is available. Because psoriasis can be persistent, gaining control may require trying different types or a combination of treatments.
Laser Light Therapy and Laser Psoriasis Treatment
Under a dermatologist’s care, light therapy can provide safe and effective treatment. Because too much ultraviolet (UV) light can exacerbate psoriasis, it is important to see a dermatologist for treatment. Never try to self-treat by using a tanning bed or by sunbathing.
Light therapy is not for everyone. Some patients’ skin may be too sensitive and other patients cannot spare the time that light therapy requires, since several treatments a week are necessary. Patients must go to a dermatologist’s office, psoriasis center, or hospital for each treatment.
If light therapy is appropriate for a patient, the dermatologist may prescribe the following:
- Laser Therapy: A laser can target the psoriasis and not touch the surrounding skin. Because the light treats only the psoriasis, a strong dose of light can be used. This offers many people an effective way to treat a stubborn patch of psoriasis, such as on the scalp, feet, or hands. A laser is not the appropriate treatment for psoriasis that covers a large area.
- Ultraviolet Narrow Band Light: The most specialized and specific light treatment for psoriasis. To receive this therapy, a patient stands in a lightbox or in front of a light panel. If the psoriasis responds, about 24 treatments over a two-month period should clear the psoriasis. Although UVB is safe and effective, it does have possible side effects such as burns, freckling, and premature skin aging.
- PUVA: A dermatologist may prescribe PUVA when psoriasis does not respond to other treatments. This course combines a medication called psoralen with UVA light therapy. Psoralen increases a person’s susceptibility to UVA light. The patient may be asked to apply psoralen to the skin or take a pill containing psoralen. After a certain amount of time passes, the patient enters a UVA light box. Research shows that PUVA is effective in about 85% of cases.
- Goeckerman Therapy or Ingram Regiment: This combination of topical therapy with UV light can be very effective for treating severe psoriasis. There are disadvantages: neither is widely available in the United States and they both require intensive treatment for several hours a day in a psoriasis clinic or hospital. Most patients receive treatment five days a week for three to five weeks. When light therapy is effective, some patients may receive a prescription for a home UV unit. Those patients are carefully monitored and must see a dermatologist for skin checkups.
Drug Treatments for Psoriasis
The following describes the different treatments that the FDA has approved for psoriasis.
- Topical Medicine: Applied to the skin, these medicines help control mild to moderate psoriasis.
Corticosteroids (Cortisone): The most frequently prescribed medication for treating mild to moderate psoriasis, it is available as a cream, ointment, gel, foam, spray, and lotion.
- Anthralin: This medication is often used to treat thick patches of psoriasis. In the past, many patients disliked using it because anthralin would irritate and stain the skin. With newer formulas and new ways to use this medication, these problems rarely occur.
- Calcipotriene and Calcipotriol (Vitamin 03 Preparations): Many patients use this medication combined with a corticosteroid. Using both medications as prescribed can be very helpful. To avoid side effects such as irritated skin, always use as directed.
- Retinoids (Vitamin A Preparations): Some patients find that applying this medication to their psoriasis is enough to control the psoriasis. For patients who need a bit more help, a dermatologist may prescribe a topical (applied to the skin) corticosteroid. Women should not use a retinoid if they are pregnant.
- Coal tar: For more than 100 years, coal tar has been used to safely and effectively treat psoriasis. Many patients disliked this treatment because it was messy and had an awful odor. Newer products work much better.