Psoriasis is a chronic autoimmune disease that develops when a person’s immune system sends faulty signals that tell skin cells to grow too quickly. New skin cells form in days instead of weeks. These excess skin cells are not shed, and pile up on the surface, causing “plaques” or patches, of psoriasis to form.
Psoriasis is the most common autoimmune disease in the United States, afflicting 7.5 million people. It can affect any part of the body. Psoriasis is often linked to other serious health conditions, such as diabetes, cardiovascular disease, and depression.
About one-third of people with psoriasis have a family member with the disease. Scientists believe that at least 10 percent of the population inherit one or more of the genes that create the tendency to develop psoriasis, but only two to three percent of the population will develop the disease.
It is believed that to develop psoriasis a person must have a combination of the genes and exposure to environmental triggers. Known triggers include:
- Stress: Can cause the disease to appear for the first time or aggravate existing psoriasis. Relaxation and stress reduction may help prevent stress from affecting the disease.
- Injury or trauma to skin: Vaccinations, sunburn, and scratches are known to trigger a psoriatic response. Early treatment can minimize such a response.
- Medications: Some are known to trigger psoriasis. Lithium, which is used to treat bipolar disorder and other psychiatric disorders, aggravates psoriasis in about half of people with psoriasis who take it. Antimalarials, such as chloroquine and hydroxychloroquine, may cause a flare of psoriasis, usually two to three weeks after the drug is taken. Inderal, used primarily for high blood pressure, will worsen psoriasis in 25 to 30 percent of people with psoriasis who take it. It isn't known if other medications in the same class (beta blockers) have the same effect, but they may have the potential for a similar reaction. Quinidine, a heart medication, has been reported to aggravate psoriasis. Indomethacin, used to treat arthritis, may worsen psoriasis. Infection, particularly with streptococcus (the bacteria which causes strep throat) can be a trigger. It is often associated with the first onset of guttate psoriasis in children. Some people with psoriasis report that allergies, diet, and weather trigger their disease.
About 95 percent of the time, a diagnosis can be made by visual inspection, however, sometimes a skin biopsy is required to make a definitive diagnosis.
There are five types of psoriasis:
- Plaque psoriasis is characterized by red patches with a silvery-white buildup of dead skin cells, appearing most often on the scalp, knees, elbows and lower back. They are often itchy, painful, and may crack and bleed.
- Guttate psoriasis often starts in childhood or young adults. It is the second most common type of psoriasis, occurring in about 10 percent of people who get psoriasis.
- Inverse psoriasis shows up as very red lesions in body folds. It may appear smooth and shiny. Many people have another type of psoriasis on the body at the same time.
- Pustular psoriasis is characterized by white pustules, blisters of noninfectious pus composed of white blood cells, surrounded by red skin. It is not infectious or contagious.
- Erythrodermic psoriasis is a particularly inflammatory form that often affects most of the body surface. It's rare, occurring in three percent of people who have psoriasis, often with unstable plaque psoriasis. The lesions are not clearly defined. There is widespread, fiery redness and exfoliation of the skin, with severe itching, and often pain. This form of psoriasis can be life-threatening.
Psoriasis can be mild, moderate, or severe. Disease on less than three percent of the body is considered mild, and constitutes about 80 percent of cases. Three to 10 percent of the body affected is considered moderate; more than 10 percent of the body affected is considered severe.
Twenty percent of cases are moderate to severe. The severity is also measured by how much the disease affects a person's quality of life. Psoriasis can have a severe impact on daily activities, even if it involves a small area, such as the palms of the hands or soles of the feet.
Psoriasis is not preventable, but it may be helpful to avoid the triggers if possible. Common triggers include skin irritation, cuts, tattoos and certain medications. Infections such as streptococcal throat infections can also trigger psoriasis. Increasingly, it has been shown that dietary choices can also affect psoriasis, with high glycemic index foods causing flares of psoriasis.
With mild disease, such as patches on the scalp, knees, elbows, hands and feet, topical treatments are sufficient to manage the plaques. Moderate to severe disease usually involves a combination of treatments: topical, phototherapy, and systemic medications.
Topical treatments, medications applied to the skin, are the first line of defense in treating psoriasis. They slow down, or normalize, excessive skin cell reproduction and reduce inflammation. Some are available over the counter (OTC) while others require a prescription.
There are two active ingredients in OTC preparations which are approved by the FDA for the treatment of psoriasis: salicylic acid and coal tar. Salicyclic acid is a keratolytic, an agent that is applied on the skin to soften the keratin. Keratolytics loosen and assist exfoliation of the skin cell causing the outer layers of skin to shed. It softens and removes psoriasis scales. It can cause irritation if left in contact with the skin for too long.
Tar, derived from coal, can slow the rapid growth of skin cells and restores the skin's appearance. It can also reduce inflammation and itching.
There are other products that contain substances such as aloe vera, jojoba, zinc pyrithione, and capsaicin, which are used to moisturize, soothe, remove scale or relieve itching. The effectiveness of these agents is not known. They can cause side effects or allergic reactions. If irritation occurs, discontinue use.
Keeping the skin lubricated is important to reduce redness and itching. Use fragrance-free products. Apply moisturizers after showering and washing hands. Use moisturizing soaps. Limit lukewarm showers to 10 minutes or less. Baths with oil, oatmeal, Epsom salts or Dead Sea salts can remove scales and relieve itching.
Prescription, nonsteroidal topical treatments include vitamin D derived medications. Topical steroids can be used for mild psoriasis.Phototherapy
Phototherapy involves exposing the skin to ultraviolet light on a regular basis, under medical supervision. Treatments are done in a doctor's office, psoriasis clinic, or at home with a phototherapy unit. The key to success is consistency.
The National Psoriasis Foundation does not support the use of indoor tanning beds as a substitute for medically-supervised phototherapy. The American Academy of Dermatology, the FDA, and the Centers for Disease Control and Prevention (CDC) all discourage the use of tanning beds and sun lamps.
Ultraviolet light B (UVB)/Ultraviolet light A (UVA) treatments penetrate the skin and slow the growth of affected skin cells. The psoriasis may worsen temporarily before improving. Occasionally, temporary flares occur with UV light therapy. It can be combined with topical or systemic treatments, dramatically increasing the effectiveness of other systemic agents.
The excimer laser, recently approved by the FDA for treating chronic, localized psoriasis, emits a high-intensity beam of UVB. The pulsed dye laser is approved for the same. It destroys the tiny blood vessels that contribute to the formation of psoriatic plaques.
Systemic medications are taken by mouth in liquid or pill form, or given by injection. They include:
● Acitretin is a synthetic form of vitamin A that slows the rapid cell turnover seen in psoriatic skin.
● Cyclosporine suppresses the immune system. It was first used to help prevent rejection in organ transplant patients. The FDA has approved it for adults with severe psoriasis.
● Methotrexate was initially used to treat cancer. It inhibits an enzyme involved in the rapid growth of skin cells. Its use must be monitored very closely; it carries many warnings of adverse effects and side effects.
Biologic drugs, also called "biologics," are used for moderate to severe psoriasis. They are given by injection or intravenous (IV) infusion, targeting specific parts of the immune system. Biologics work by blocking the action of a specific type of immune cell, called T cells, or by blocking proteins in the immune system that trigger the body to create inflammation. Some of the biologics are: Enbrel, Humira, Remicade, Simponi and Stelara. There are significant risks and side effects.
Biologic drugs are used to treat moderate to severe psoriasis. They are given by injection or intravenous (IV) infusion, and each target specific parts of the immune system. Some biologics work by blocking the action of a specific type of immune cell, called T cells, or by blocking proteins in the immune system that trigger the body to create inflammation. Some common biologics include: Enbrel, Humira, Remicade, Simponi and Stelara. There are significant risks and side effects to each one, and treatment with these medications should be done under the supervision of a doctor.
Alternative therapies include:
- Meditation is believed to result in greater physical relaxation and mental calmness.
- Spa Therapy is the use of mineral waters. It is believed to help the skin trap hydration and to soften the skin, breaking down the plaques that characterize psoriasis.
Living With Psoriasis
Stress can cause the immune system to send out chemicals that cause inflammation. In people with psoriasis, the immune system over-responds, sending out too much of the chemicals. The person with psoriasis needs to minimize physical and mental stress.
The itch of psoriasis can have a bigger impact on quality of life than visible lesions. It is a unique itch, often described as a burning, biting sensation. Some describe it as the feeling of being bitten by fire ants.
At-home remedies for the itch include keeping skin moisturized. It reduces inflammation, itching, and helps the skin heal. Minimizing scaling and flaking are helpful. Cold showers and cold packs can help relieve itching.
Psoriasis can affect relationships in a number of ways. It can be difficult to talk to family and friends about the disease. Dating may be avoided due to poor body image. Genital psoriasis can have a significant impact on sex and intimacy. Depression is the most common disease associated with psoriasis; it's twice as common as it is in the general population. It can have a significant impact on quality of life.
People with psoriasis are more likely to have suicidal thoughts and attempts. A person with the symptoms of depression should be seen by a physician. The symptoms include:
● Inability to sleep
● Inability to get out of bed
● Loss of energy
● Lack of interest in things previously enjoyed
● Inability to focus
Working with psoriasis and psoriatic arthritis can be challenging. Meeting with a supervisor to discuss how psoriasis may affect job performance is helpful. The workplace should be made comfortable. It may be necessary to invent ways to perform routine work tasks. The work area and schedules should be kept organized. Learn about disability benefits and eligibility requirements before they become necessary.
Your Questions About Psoriasis Answered
Is psoriasis contagious? No, because it is not an infection.
Does what I eat affect psoriasis? Foods can improve or aggravate psoriasis. More information is available from the National Psoriasis Foundation (NPF).
Can the plaques become cancerous? There are no reports of psoriatic lesions transforming into cancer.
Is there a cure for psoriasis? At the present time there is no cure, but there is ongoing research focused on finding a cure.
What services are available in my area? Events and programs can be found on the NPF site.
Can I pass psoriasis on to my children? You can pass on the genes for psoriasis.
What about being pregnant with psoriasis? Pregnancy can change psoriasis, and many of the medications used to treat psoriasis are not compatible with pregnancy. Discuss pregnancy with your doctors before getting pregnant.
Will my psoriasis get better with age? There is no clear connection between age and severity of psoriasis.
I feel so alone with this disease. What can I do? One of the most powerful tools to help with managing the emotional effects is to get to know other people who also live with psoriasis. Go to https://www.psoriasis.org for ways to get connected.
Can I die from psoriasis? Only one of the 5 types of psoriasis can potentially be deadly - erythrodermic psoriasis. This type is rare, occurring in only 3 percent of people with psoriasis. Death is exceedingly rare.
More information National Psoriasis Foundation 6600 SW 92nd Ave. Ste. 300 Portland, OR 97223 www.psoriasis.org 800-723-9166 firstname.lastname@example.org
Article Written By Sheila M. Krishna M.D., FAAD
Dr. Krishna is a board certified dermatologist. She received her undergraduate degree at the Massachusetts Institute of Technology where she double majored in biology and foreign languages and graduated with Phi Beta Kappa honors. She is fluent in both English and Spanish. Dr. Krishna received her medical degree at the David Geffen School of Medicine at the University of California, Los Angeles, where she was a member of the Alpha Omega Alpha Medical Honor Society. She completed her dermatology residency at the Virginia Commonwealth University in Richmond, Virginia, and she served as Chief Resident in the Department of Dermatology. She completed an additional research year at UCLA with Dr. Lloyd Miller, where she gained expertise in research methods and protocol design and execution. Dr. Krishna is a Fellow of both the American Academy of Dermatology (AAD) and the American Society for Mohs Surgery (ASMS). Dr. Krishna practices in San Diego, California where she treats adults and children for skin conditions. Dr. Krishna was selected as a Top Doctor by her peers in San Diego in 2017. Website - https://www.sheilakrishnamd.com/