Last Updated: April 20, 2018

Psoriasis

Overview

Psoriasis is a chronic inflammatory disorder of the skin, in which the skin produces new skin cells too quickly. Normally, in a process called turnover, the lowest level of the epidermis produces new skin cells that rise to the outermost layer of the skin in a period of one month. In psoriasis, rapid turnover occurs in only a few days. In the most common forms of psoriasis, excess skin cells accumulate on the skin surface, resulting in thick patches (plaques) of reddened, inflamed skin covered with silvery white scales.

This disease usually develops in individuals between the ages of 15 to 30 years. Psoriasis is a life-long condition, erupting at unpredictable intervals, alternating with periods of remission.

Causes and Risk Factors

patient with psoriasis on back and arms

The underlying cause of psoriasis is unknown. However, research has established that psoriasis is the result of a malfunction of the immune system, in which certain white blood cells (termed T cells) mistakenly attack the skin, triggering inflammation and rapid skin cell turnover.

Risk factors for the development of psoriasis include the following:

Symptoms

Individuals with psoriasis usually develop raised red plaques with silvery white scales, associated with itching and pain. Reddened skin beneath the plaques easily bleeds when the scales are removed. Plaques can range from tiny spots to extensive eruptions across large areas.

Typically, psoriasis erupts symmetrically, but unilateral symptoms can occur. Affected areas usually include the extensor surface of the elbows, knees, scalp, lower back, buttocks and genital area. Commonly, nails appear thickened, pitted and deformed.

Symptoms are characterized by cycles of worsening (flares) for weeks or months followed by periods of improvement or even complete remission. Additionally, individuals with psoriasis frequently feel self-conscious about the appearance of their skin, which can result in social isolation and depression.

Characteristics of the Major Types of Psoriasis

Chronic Plaque Psoriasis:

Guttate Psoriasis:

Scalp Psoriasis:

Inverse Psoriasis:

Pustular Psoriasis:

Erythrodermic Psoriasis:

Psoriatic Arthritis:

psoriasis plaques

Diagnosis and Treatment

Most cases of psoriasis are diagnosed by the patient’s symptoms and physical examination. Rarely, a skin biopsy is necessary to rule out other conditions that may resemble psoriasis.

There is no cure for psoriasis; therefore, the main goal of treatment is to slow the rapid turnover of skin cells and relieve symptoms.

Topical Treatment

In treating psoriasis, medications are applied directly to the surface of the skin.

Light Therapy

Sunlight:

Ultraviolet B (UVB) Phototherapy:

Narrowband UVB Therapy:

Goeckerman Therapy:

Psoralen and Ultraviolet A (UVA) Phototherapy (PUVA):

Excimer Laser:

Systemic Treatment

In the case of these treatment methods, medications are administered orally or by injection for severe cases of psoriasis.

Methotrexate:

Retinoids:

Cyclosporine:

Biologic response modifiers (biologics):

Prevention

There are no known preventative measures for psoriasis and genetics is a major risk factor for this disease. However, individuals may decrease their risk by avoiding other factors such as smoking, stress and obesity.

Sources

Related Topics

Carla Hightower, MD

Dr. Hightower is an experienced physician who studied medicine at Northwestern University, where she also earned an MBA. As the founder of Living Health Works, she offers health coaching to individuals, private groups and corporations.