Psoriasis most commonly appears on the scalp, knees, elbows and torso. But psoriasis can develop anywhere, including the nails, palms, soles, genitals and face (which is rare). Often the lesions appear in a symmetrical fashion, in the same place on the right and left sides of the body.
Do people know they are going to get Psoriasis?
It is not possible to predict who will get psoriasis, although heredity clearly plays a role in predisposing people to develop the disease. A family association exists in one out of three cases. However, there is no established pattern of inheritance, so many people cannot trace a family history of psoriasis. Environmental factors such as physical trauma to the skin, infections, stress and reactions to certain drugs may trigger the onset of psoriasis, even in people without an apparent family history of psoriasis.
How is Psoriasis diagnosed?
No special blood test or other diagnostic tool exists for psoriasis. The diagnosis is usually determined through examination of the skin by a doctor. Less commonly, a skin biopsy is examined under the microscope for biological evidence of psoriasis. The presence of small pits in the fingernails is also an indicator of psoriasis.
Is all Psoriasis alike?
No. There are various forms of psoriasis. Plaque psoriasis is the most common. Other forms are:
Types of Psoriasis
Psoriasis comes in many forms. Each differs in severity, duration, location, and in the shape and pattern of the scales. The most common form begins with little red bumps. Gradually these grow larger and 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.
Elbows, knees, groin and genitals, arms, legs, palms and soles, scalp and face, body folds and nails are the areas most commonly affected by psoriasis. It will often appear in the same place on both sides of the body.
Nails with psoriasis have tiny pits on them. Nails may loosen, thicken or crumble and are difficult to treat.
How Is Psoriasis Conventionally Treated?
The goal is to reduce inflammation and to control shedding of the skin. Moisturising 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 treatments and several visits to a doctor or dermatologist may be needed.
The doctor may prescribe medication to apply on 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 it must be used cautiously. Ultraviolet light therapy, however, may be given under the guidance of a consultant dermatologist.
What Are The Current Treatment Options?
Steroids (Cortisone) - Cortisone creams, ointments, and lotions may clear the skin temporarily and control the condition in many patients. Weaker preparations should be used on more sensitive areas of the body such as the genitals, groin, and face. Stronger preparations will usually be needed to control lesions on the scalp, elbow, knees, palms and soles, and parts of the torso and may need to be applied under dressings. These must be used cautiously and with the dermatologist's instruction. Side effects of the stronger cortisone preparations include thinning of the skin, dilated blood vessels, bruising, and skin colour changes. Stopping these medications suddenly may result in a flare-up of the disease. After many months of treatment, the psoriasis may become resistant to the steroid preparations.
The dermatologist may inject cortisone in difficult-to-treat spots. These injections must be used in very small amounts to avoid the associated side effects.
How Is Psoriasis Of The Scalp Conventionally Treated?
The treatment for psoriasis of the scalp depends on the seriousness 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 or cortisone. The patient must take care to avoid harsh shampooing and scratching the scalp.
Anthralin - a medication that works well on tough-to-treat thick patches of psoriasis. It can cause irritation and temporary staining of the skin and clothes. Newer preparations and methods of treatment have lessened these side effects.
Vitamin D
A synthetic Vitamin D, Calcipotriol, is available in prescription form. It is useful for individuals with localised psoriasis and can be used with other treatments. Limited amounts should be used to avoid side effects. Ordinary Vitamin D, as one would buy in a chemist or health food store, is of no value in treating psoriasis.
Retinoids
Prescription vitamin A-related gels may be used alone or in combination with topical steroids for treatment of localised psoriasis. Women who are or may become pregnant should not use topical retinoids.
Coal Tar
For more than l00 years, coal tar has been used to treat psoriasis. Today's modern products are a vast improvement and less messy. Stronger prescriptions can be made to treat difficult areas.
Methotrexate
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.
Retinoids
Prescription oral vitamin A-related drugs may be prescribed alone or in combination with ultraviolet light for severe cases of psoriasis. Side effects include dryness of the skin, lips and eyes, elevation of fat levels in the blood, and formation of tiny bone spurs. Oral retinoids should not be used by pregnant women or women of childbearing age who intended to become pregnant during or within 3 years of discontinuation of therapy, as birth defects may result. Close monitoring is required together with regular blood tests.
Goeckerman Treatment
Named after the Mayo Clinic dermatologist who first reported it in 1925. Combining coal tar dressings and ultraviolet light, it is used for patients with severe psoriasis. The treatment is performed daily in specialised centers. Ultraviolet exposure times vary with the kind of psoriasis and the sensitivity of the patient's skin.
Light Therapy
Sunlight and ultraviolet light slow the rapid growth of skin cells. Although ultraviolet light or sunlight can cause skin wrinkling, eye damage, and skin cancer, light treatment is safe and effective under a doctor's care. People with psoriasis all over their bodies may require treatment in hospitals equipped with light boxes for full body exposure. Psoriasis patients who live in warm climates may be directed to carefully sunbathe. Seek the advice of a doctor before self-treating with natural or artificial sunlight.
PUVA
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, then are exposed to a carefully measured amount of a special form of ultraviolet (UVA) light. It takes between 25 & 40 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. Because Psoralen remains in the lens of the eye, patients must wear UVA blocking eyeglasses when exposed to sunlight from the time of exposure to Psoralen until sunset that day. PUVA treatments over a long period increase the risk of skin aging, freckling, and skin cancer. Dermatologists and their staff must monitor PUVA treatment very carefully.