What is plaque psoriasis?
Plaque psoriasis is the most common form of psoriasis, a chronic autoimmune disease that causes raised, red, scaly patches covered with silvery scales on the skin. These lesions are known as plaques. Plaques often itch and may be painful. They may appear anywhere on the body, but usually affect the outside of the elbows, knees or scalp. Plaques also develop in skin folds under the arms and breasts.
Who is at risk for plaque psoriasis?
Genetics and Triggers
Researchers believe about 10% of the population inherit one or more of the genes that could lead to psoriasis, but only about 2% to 3% of the population develop the disease. Scientists believe the reason is because the person with a genetic predisposition to psoriasis must be exposed to external factors known as “triggers” for the disease to become active. Psoriasis triggers are unique to the individual, but include stress, injury to the skin, infection and certain medications.
While anyone may develop psoriasis, the following factors can increase your risk of developing the disease:
- Family history – Having a family member with psoriasis is the most significant risk factor for developing the disease.
- Viral and bacterial infections – People with HIV are more likely to develop psoriasis than those with a healthy immune system, as are children and young adults who experience recurring infections, such as strep throat
- Stress – High stress level can impact your immune system and may increase your risk of psoriasis
- Obesity – Excess weight may increase your risk of psoriasis.
- Smoking – Tobacco use increases your risk of developing the disease and may increase the severity psoriasis.
If I have plaque psoriasis, will I develop psoriatic arthritis?
If you have psoriasis or plaque psoriasis, it’s possible you may eventually develop psoriatic arthritis. Up to 30% of people with psoriasis develop this inflammatory form of arthritis.
Studies show that earlier treatment for psoriatic arthritis can help preserve strength and delay joint damage. If you believe you may be experiencing symptoms of psoriatic arthritis, talk with your doctor about treatment options. Early diagnosis and treatment can avoid injury and joint disease.
Symptoms of psoriatic arthritis include:
- Overall fatigue
- Pain and swelling of the tendons
- Swollen fingers and toes
- Stiffness, pain, throbbing and swelling in one or more joints
- Nail changes (nail separates from nail bed and/or becomes pitted and mimics fungus infections)
- Redness and pain of the eye, such as conjunctivitis
How is plaque psoriasis diagnosed?
Although there are no blood tests or diagnostic tools to diagnose plaque psoriasis, a dermatologist or other health care provider, such as your primary care physician can usually examine the affected skin and determine if it is psoriasis. Your healthcare provider may take a biopsy of the affected skin to examine microscopically to see if your skin looks thick and inflamed. Your doctor will also ask about your family history, since about one-third of people with psoriasis have a family member with the disease.
How is plaque psoriasis treated?
There are a number of treatments for plaque psoriasis. Discuss your options with your doctor and decide which therapy is right for you. Some of these options include light therapy or topical solutions (creams, ointments, etc.), which are usually the prescribed in the early stages of the disease.
Other treatments include:
Biologic therapy is a protein-based drug derived from living cells cultured in a laboratory. These drugs are given by injection or intravenous (IV) infusion. Rather than impacting the entire immune system, like traditional systemic drugs, biologics are more targeted. Biologics used to treat psoriatic disease block the action of a specific type of immune cell called a T cell, or block proteins in the immune system, such as tumor necrosis factor-alpha (TNF-alpha), interleukin 17-A, or interleukins 12 and 23. These cells and proteins all play a major role in developing psoriasis and psoriatic arthritis.