Psoriasis: causes, symptoms, and treatment here

What is psoriasis?

Psoriasis is a chronic (long term) skin disease that causes red, itchy, scaly patches, most commonly on the knees, elbows, trunk and scalp. Psoriasis has no cure, and it is not contagious. It can be treated and controlled, but usually returns. Psoriasis fluctuates between flares, where the condition is active, to remission where the itching, pain and rash go away. Psoriasis is common, affecting almost eight million American adults. Its underlying cause is unclear but it’s believed to be caused by dysfunction of the immune system that causes inflammation in the body. It can affect anyone, of all skin colors and types, and commonly starts between ages 15 to 25.

Why should I worry about psoriasis?

Although psoriasis can be controlled with treatment, it’s hard to live with when it’s active. It can cause mental health issues such as low self-esteem and depression. It also increases your risk of developing other diseases, including psoriatic arthritis, eye problems, obesity, type 2 diabetes, heart disease and high blood pressure. It can cause other autoimmune diseases such as celiac disease, sclerosis and inflammatory bowel disease.

What causes psoriasis?

Normal skin takes about a month to grow new skin and then shed it. In psoriasis patients. skin grows in three or four days because the immune system causes rapid skin cell growth. But, instead of the skin shedding, cells pile up on the skin’s surface. They form plaque, scale, and red patches that can be very itchy, and burn or sting. Why the immune system doesn’t function normally is unknown. It’s thought that a combination of genetics and factors in the environment cause psoriasis. It’s possible to develop psoriasis with no family history of the disease.

Psoriasis flares (when the symptoms return) can be triggered by environmental factors that, in turn, cause a change in the immune system. Although the triggers vary from person to person, the most common triggers are:

Illness or infections, such as skin infections or strep throat
Skin injuries, even a minor cut or scrape, or bug bite
Severe sunburn
Cold, dry weather, and long periods of reduced sunlight and humidity
Smoking and exposure to secondhand smoke
Excessive alcohol consumption
Stress, one of the most common triggers, can make itching worse
Medications such as lithium, high blood pressure meds and antimalarial drugs
Rapid withdrawal of corticosteroids
Allergies and certain foods act as triggers for some people

It’s very helpful to keep a list of when your symptoms flare and what triggers may have caused it. This helps you and your doctor determine your personal triggers so you can avoid them.

Who’s at risk for psoriasis?

You have a higher risk of developing psoriasis if you have:

Family history of psoriasis
High levels of unrelieved stress; stress has an impact on your immune system
Smoking increases both the risk of psoriasis and the severity of flares

What are the symptoms of psoriasis?

Symptoms vary from person to person. The most commonly affected areas are scalp, face, palms, elbows, lower back, knees, legs, and soles. The most common symptoms include:

Red inflamed patches of skin, covered with thick, silvery scale that range from a few spots of dandruff-like scale to major eruptions covering large areas
Dry, cracked skin that may bleed
Itching, burning, tenderness or soreness
Thick, pitted or ridged nails
Swollen, stiff joints
Internal inflammation can have a negative effect on internal organs and tissues.
Mental health issues including depression and poor self-esteem

Psoriasis goes through cycles where it flares up for weeks or months, then calms down or may go into remission (when no symptoms are present).

The most common areas affected by psoriasis include:

Are there different types of psoriasis?

Plaque psoriasis, the most common type (80% of all cases), causes dry, raised and red patches of skin covered with silvery scales. Skin can be itchy or tender, and the affected area can be large or small.
Fingernail or toenail psoriasis causes one or more nails to be pitted, discolored, thickened and grow abnormally. They may crumble and separate from the nail bed. Fingers and toes can be tender and painful.
Guttate psoriasis is triggered by a bacterial infection, and primarily affects children and young adults. Inflammation causes small, round, red, scaly lesions that are more common on the chest, back, arms and legs.
Inverse psoriasis mainly affects the skin folds of the groin, buttocks and breasts, causing smooth patches of painful, itchy, red, inflamed skin. It worsens with friction and sweating. Fungal infections may trigger it.
Psoriatic arthritis causes swollen, stiff and painful joints. Those may be the only symptoms. Symptoms range from mild to severe, and serious cases can lead to permanent joint damage. About a third of people with psoriasis also develop psoriatic arthritis.
Pustular psoriasis is rare. It causes pus-filled lesions or bumps that are surrounded by red, inflamed skin over a widespread area. It can also cause small areas of lesions on palms and soles. ‍
Erythrodermic psoriasis is rare, and can cover the entire body with a red, peeling rash that sheds in large sheets of dead skin. It can itch and burn intensely, and can be life-threatening. It also causes changes in heart rate and temperature, and dehydration.

How is psoriasis diagnosed?

Your doctor will examine your skin, scalp and nails. He/she may do a biopsy by taking a small sample of skin and examining it under a microscope. This helps determine the type of psoriasis and rules out other disorders.

What are the treatments for psoriasis?

The goal of psoriasis treatment is to remove scales, stop skin cells from growing out of control, and reduce the symptoms of itching, pain, and inflammation. Treatment will depend on the type of psoriasis you have, how severe it is and how it’s responded to previous treatment. Treatment starts with the mildest treatment and adds stronger treatments only if necessary to slow skin cell growth with the fewest side effects. You may be prescribed a combination of treatments or different medications until you find what works best for you. Even with periods of remission, the disease usually returns.

Treatments include:

Corticosteroids are prescribed for mild to moderate psoriasis. Topical corticosteroids are available in creams, ointments, lotions, gels, sprays and shampoos. They’re applied daily during a flare and every other day to maintain remission. These medications can thin the skin, and may stop working over time.
Oral or injected corticosteroids may be used if you have just a few, small, but severe and persistent patches. They are directly injected into lesions.
Synthetic vitamin D can slow skin cell growth, and may be used in combination with corticosteroids.
Retinoids are applied once or twice a day. They can irritate the skin and cause increased sensitivity to light. Oral retinoids reduce the overproduction of skin cells, but may cause muscle soreness and dry skin.
Calcineurin inhibitors can reduce inflammation and the buildup of plaque in areas of sensitive, thin skin. This medication cannot be used long term because it increases the risk of skin cancer and lymphoma.
Salicylic acid in shampoos and scalp solutions can reduce scaling.
Coal tar reduces scaling, itching and inflammation but can irritate the skin. It’s messy to use, stains clothing and has a strong odor.
Goeckerman therapy combines coal tar with light therapy for a more effective therapy than either method can provide alone.
Anthralin slows skin cell growth, can remove scales and make skin smoother. Because it can irritate skin and stains anything it touches, it’s applied for a short time and then washed off.
Methotrexate decreases overproduction of skin cells and suppresses inflammation. You’ll need long-term testing to monitor blood and liver function. It can cause stomach upset, loss of appetite and fatigue.
Cyclosporine is taken orally for severe psoriasis to suppress the immune system. It cannot be taken for more than a year. It increases risk of infections and cancer, and requires regular monitoring of blood pressure and kidney function.
Biologics are injected drugs that alter the immune system to disrupt the disease cycle. They can improve symptoms within weeks, but can increase serious infection risk. They’re used to treat moderate to severe cases that haven’t responded to milder treatments.
Light therapy is used for moderate to severe psoriasis, and may be combined with medications. You’ll need repeated treatments of exposure to natural and/or artificial light.
Ultraviolet B broadband is artificial light that can treat small patches or widespread psoriasis, especially cases that don’t improve with topical medications. It can cause redness, itching and dry skin.
Ultraviolet B narrowband is replacing broadband because it is more effective. It is given two to three times a week until skin improves; then less frequently for maintenance therapy. It can cause more-severe and longer lasting burns.
Psoralen plus ultraviolet A (PUVA) involves taking a light-sensitizing medication that makes skin more responsive to UVA light exposure. UVA light penetrates deeper into the skin than UVB light. It’s used for severe cases, but can cause nausea, headache, burning and itching in the short term. Long-term side effects are dry and wrinkled skin, freckles, increased sun sensitivity, and increased risk of skin cancer, including melanoma.
Excimer laser uses a strong UVB light to target only the affected skin. It can cause redness and blistering.

National Psoriasis Foundation. (May 2021). About Psoriasis. Retrieved 9-28-21, {https://www.psoriasis.org/about-psoriasis/}

National Psoriasis Foundation. (April 2021). Psoriasis: Causes and Triggers. Retrieved 9-28-21, {https://www.psoriasis.org/causes/}

National Psoriasis Foundation. (Nov 2020). Life With Psoriasis. Retrieved 9-28-21, {https://www.psoriasis.org/life-with-psoriasis/}

Mayo Clinic. (May 2020). Psoriasis. Retrieved 9-28-21, {https://www.mayoclinic.org/diseases-conditions/psoriasis/symptoms-causes/syc-20355840#:~:text=Psoriasis%20is%20a%20skin%20disease,while%20or%20going%20into%20remission.}

Mayo Clinic. (May 2020). Psoriasis: Diagnosis and Treatment. Retrieved 9-28-21, {https://www.mayoclinic.org/diseases-conditions/psoriasis/diagnosis-treatment/drc-20355845}

Medically reviewed by:

Dr. Javeed Siddiqui, MD, MPH

Dr. Siddiqui is the Chief Medical Officer at TeleMed2U responsible for clinical and technical program development as well as maintaining a thriving telemedicine practice in infectious diseases which includes specialized care of Hepatitis and HIV.

‍Meet our doctors

Psoriasis