Psoriasis: This is what you need to know and why

Psoriasis is a common autoimmune disease that affects the skin, not a cosmetic problem, but many people don’t understand what is, who it affects, or the impact it has on the people who have to live with it. It is important to know what the different types of psoriasis look like and how you and your doctor can determine whether or not you or a loved one has it. 

What is psoriasis?

Psoriasis is the most common autoimmune disease in the United States, affecting around 2.2% of Americans and an average of 3% of people in other western countries.

• Age: it is most commonly seen in adults but can affect children. 
• Gender: Until recently, psoriasis was thought to have no favor of gender, showing an equal amount of cases in both male and females. Recent research has detected a developing pattern of greater occurrences in females below 18 and in males above 18.
• Geography:  Locations around the equator have a smaller population of people with psoriasis versus those who live farther away.
• Heritability: One in 10 people inherit at least one of the genes that can lead to psoriasis.

What are the types of psoriasis?

Psoriasis is a blanket term for a spectrum of conditions caused by an overactive immune system initiating an inflammatory response against the skin. It comes in four main types that each have their own unique causes, physical symptoms, and treatments. General triggers for psoriasis can include medications, infections, trauma or injury to the skin, smoking, alcohol, and stress.

The National Institutes of Health has published descriptions of the main types of psoriasis:

Plaque-type psoriasis:  Plaque-type psoriasis is the most common type, affecting 80-95% of psoriasis patients. 

• What it looks like: “oval or irregularly shaped, red, sharply demarcated, raised plaques covered by silvery scales.”
• Location: The most common areas occur on the elbows, knees, scalp, and lower back, but can affect every area of the body.

Guttate psoriasis: This type of psoriasis is the most likely to affect young adults and children. It is also one of the only types that can clear up on its own, though it is advised to use a topical treatment provided by a physician because it has a chance of becoming chronic or developing into plaque-type psoriasis. 

• What it looks like: “multiple small scaly plaques.”
• Location: occurs around the trunk and upper arms and thighs.

Generalized pustular psoriasis: This type of psoriasis is rare, but when it does occur it is usually an acute attack during pregnancy. Its symptoms not only include a visible rash all over the body, but also high fever, fatigue, and neutrophils leukocytosis (an increase of white blood cells designed to fight specific infections). The cause has been linked to “infection, exposure to or withdrawal from drugs.” Generalized pustular psoriasis can develop into erythrodermic psoriasis. 

Erythrodermic psoriasis: This is the rarest type of psoriasis and is potentially life- threatening. Possible triggers include sunburn, emotional stress and taking or withdrawing from corticosteroids. It can cause hypothermia, limb edema (swelling), myalgia (muscle pain), fatigue, and fever. 

• What it looks like: It appears similar to generalized pustular psoriasis — redness and inflammation on more the 75% of the body — but it can occur with and without the scaling characteristic. It differs from the scaling of plaque-type psoriasis in that it is more superficial. 

Diagnosis, Doctors, and Treatments 

Depending on the type and severity, different treatments are offered. For less severe forms of psoriasis, topical treatments are administered by a health care provider. For more moderate to severe cases, UVA/UVB phototherapy is often effective. More recently, the disease has been better understood, resulting in new drugs known as biologics. Biologics can be effective in patients who were unresponsive to other forms of medication. Some patients find their symptoms improve in the summertime when they responsibly enjoy additional sunlight.

Looking for an expert health care provider for psoriasis, skin cancer, or other skin conditions? Learn more about Swedish dermatology services and find a doctor near you. Subscribe to our blog and you'll never miss a health update. 

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This information is not intended as a substitute for professional medical care. Always follow your health care professional's instructions.