Dermatology Associates of Plymouth Meeting specializes in treating Psoriasis.

Psoriasis is a persistent and debilitating skin disease. The skin can become inflamed, with thickened red areas associated with scale. The scalp, elbows, knees, face, lower back, groin and genitals, arms, legs, palms and soles, body folds and nails are the most commonly affected areas.

Psoriasis can be a condition of extremes. In some cases, it is so mild that people don’t know they have it. Other cases are so severe that it can cover large areas of the body. The good news is that there are treatments and medications that help even the most severe cases.

It is estimated that in the United States, two out of every hundred people have some form of psoriasis. Approximately 150,000 new cases occur each year. Psoriasis is not contagious. It often runs in families because it has a genetic component that makes certain people more likely to develop it.

Please view more information about our Psoriasis Center.

Learn more about in-office treatments and medications available to treat your Psoriasis.

What Causes Psoriasis?

The cause is unknown. Some studies, however, point to an abnormality in the functioning of white cells in the bloodstream triggering inflammation in the skin. The inflammation, via a variety of chemicals that are released by the abnormal white cells, causes skin cells to divide too quickly leading to the thick reddened skin with a silvery scale.

Psoriasis can also be triggered by infections, emotional stress, injuries to the skin and reactions to certain drugs. Flare-ups are often worse in the winter, because of dry skin and a lack of sunlight.

Types of Psoriasis

Psoriasis can differ in severity, duration, location, and in shape and pattern. The most common form begins with little red bumps. The bumps can grow larger and then scales form. While the top scales flake off easily and often, scales below the surface stick together. When they are removed, the tender, exposed skin bleeds. These small red areas then grow, sometimes becoming quite large. The most common form of psoriasis is called “plaque psoriasis” — about 80 percent of people with psoriasis have this type which consists of large areas of involvement in defined areas of the body. Psoriasis affecting nails have tiny pits on them. Nails may loosen, thicken or crumble. Nail psoriasis can be difficult to treat. Inverse psoriasis occurs in the armpit, under the breast and in skin folds around the groin, buttocks and genitals.

How is Psoriasis Diagnosed?

Dermatologists diagnose psoriasis by examining the skin, nails and scalp. If the diagnosis is in doubt, a skin biopsy is usually helpful.

How is Psoriasis Treated?

The goal is to reduce inflammation and to control shedding of the skin. Moisturizing creams and lotions loosen scales and help control itching. Special diets have not been successful in treating psoriasis, except in isolated cases.

Treatment is based on a patient’s health, age, lifestyle and the severity of the psoriasis. Different types of treatment, including light therapy (which requires several visits) may be needed.

Our doctors may prescribe topical medications to apply to the skin containing cortisone-like compounds, synthetic vitamin D, tar or Anthralin. These may be used in combination with natural sunlight or ultraviolet light. The most severe forms of psoriasis may require oral medications, with or without light treatment.

Sunlight exposure helps the majority of people with psoriasis, but obviously, it must be used cautiously to avoid the risk of developing skin cancer.

Types of Treatment

Steroids (Cortisone):

Cortisone creams, ointments and lotions may help control the condition in many patients. Weaker preparations should be used on sensitive areas of the body. Stronger preparations will usually be needed to control lesions on the scalp, elbow, knees, palms and soles. These must be used cautiously and with specific instruction.

Side effects of the stronger cortisone preparations include thinning of the skin, dilated blood vessels, bruising and skin color changes. Stopping these medications suddenly may result in a flare-up of the disease. After many months of treatment, psoriasis may become resistant to the steroid preparations. Our doctors may inject cortisone in difficult-to-treat spots.

Scalp Treatment:

The treatment for psoriasis of the scalp depends on the severity of the disease, hair length and the patient’s lifestyle. A variety of non-prescription and prescription shampoos, oils, solutions and sprays are available. Most contain coal tar, salicylic acid or cortisone.


A medication that works well on tough-to-treat psoriasis. It can cause irritation and temporary staining of the skin and clothes. Some newer preparations and methods of treatment have lessened these side effects.

Vitamin D:

A synthetic Vitamin D, calcipotriene, is available in prescription form. It is useful for individuals with localized psoriasis and can be used with other treatments. Standard Vitamin D, bought in a drug store or health food store, is not proven to be of value in treating psoriasis.


Prescription vitamin A-related gels may be used alone or in combination with topical steroids for treatment of localized psoriasis.


Sunlight and ultraviolet light slow the rapid growth of skin cells. Psoriasis patients are directed to carefully sunbathe. People with psoriasis all over their bodies may require treatment with light boxes for full body exposure. Our office is equipped with the latest light treatment technology available.


When psoriasis has not responded to other treatments or is widespread, PUVA is effective in 85 to 90 percent of cases. The treatment name comes from “Psoralen + UVA,” the two factors involved. Patients are given a drug called Psoralen and are exposed to a carefully measured amount of a special form of ultraviolet (UVA) light.

Light Therapies take approximately 25 treatments, over a two- or three-month period, before clearing occurs. About 30-40 treatments a year are usually required to keep the psoriasis under control. Over a long period, light therapy increases the risk of skin aging and skin cancer. Our dermatologists monitor light treatments very carefully.


An oral anti-cancer drug that can produce dramatic clearing of psoriasis when other treatments have failed. Because it can produce side effects, particularly liver disease, regular blood tests are performed. Chest x-rays and occasional liver biopsies may be required. Other side effects include upset stomach, nausea and dizziness.


An immunosuppressant drug used to prevent rejection of transplanted organs (liver, kidneys). It is used for the treatment of widespread psoriasis when other methods have failed. Because of potential effects on the kidneys and blood pressure, close medical monitoring is required together with regular blood tests.


New injection treatments such as Enbrel, Humira, Remicade are all changing how we treat psoriasis. Each agent has its advantages. Our doctors can review this with you in more detail discussing the benefits and side effects of each agent.

Coal Tar:

For more than 100 years, coal tar has been used to treat psoriasis. Today’s products are greatly improved and less messy. Stronger prescriptions can be made to treat difficult areas.

New Therapies Under Investigation

The above treatments, alone or in combination, can clear or greatly improve psoriasis in most cases, but no treatment “cures” it. Pharmaceutical companies, dermatologists and other researchers are continually testing new drugs and treatments. We are actively engaged in research trials with a variety of Pharmaceutical companies and if appropriate, will review options with you in more detail.