What Is Psoriasis?

1) It is a chronic (long-lasting and recurring) inflammatory, non-contagious skin disease, characterized by itchy, thick, raised, red areas of skin covered with silvery-white scales. Psoriatic lesions are most commonly found on the elbows, knees, scalp and lower back—although any part of the body can be affected, including the fingernails and toenails. Affecting 1 to 3 percent of the world's population, psoriasis is one of the most common skin disorders


2) It can vary in presentation and severity. The majority of patients (approximately 80 to 90 percent) present with relatively mild disease with only limited involvement of the skin which can be controlled with topical creams. It is important to recognize that even though psoriasis might involve only limited areas of the body it can still pose a significant burden on patients' lives. This fact was emphasized recently when a major conclusion of a consensus meeting of the American Academy of Dermatology stated that it is important for doctors to not only rely on the amount or area of a patient's psoriasis when determining the severity of the disease and treatment, but also to take into account the effect the disease has on the patient's quality of life


Approximately 15 to 30 percent of psoriasis patients experience arthritis or joint inflammation, which can range in severity from mild to disabling. When severe, psoriatic arthritis can limit a person's ability to walk or work.

3) It can be intensely itchy and can burn. The disease can cause patients great discomfort, pain and emotional distress. Depending on the severity, psoriasis can affect relationships and the ability to work or enjoy leisure activities. For example, parents with tender lesions on their hands might find it difficult to care for their babies; patients with painful pustules on their hands or feet can find themselves unable to work with their hands or walk; and food handlers are constantly faced with the question: "Is that contagious?" Teens are often embarrassed by their blemished skin and are unwilling to wear shorts in gym class or during the summer. These limitations can affect both their psychosocial development and ability to enjoy normal healthy activities. In short, psoriasis can have a profound negative physical and psychological impact on patients and their families.

Patients who have more limited disease, however, might not experience much discomfort, nor be emotionally distressed by its appearance. There are even patients with extensive areas of their bodies involved who are not physically or emotionally affected to any great degree.

Signs and Symptoms

4) It is most commonly appears as red, raised, dry scaly areas of the skin. In addition, nail changes such as deformity and crumbling of the nail plate can occur. Arthritis can also be present with joint swelling, tenderness and stiffness.

The physical appearance and symptoms of psoriasis vary depending on the type of psoriasis and the severity of the disease. The appearance can also vary from person to person and psoriasis lesions can differ in size from several millimeters to several centimeters.

A lesion that is less than 1 cm in diameter (and is raised above the surface of the skin), is called a papule, and a raised lesion that is greater than 1 cm in diameter is called a plaque. Some people can have pustules present on the palms and soles or on other areas of the body. Psoriasis can be localized involving the elbows and knees, or widespread, covering the entire body.

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