Psoriasis: Symptoms, Causes, and Treatments
by the WoundSource Editors
Psoriasis is a chronic, noncontagious skin disease resulting from an atypical autoimmune response which leads to accelerated skin growth and the formation of skin lesions. Psoriasis causes skin cells that typically take a month to grow to form in a matter of days. This in turn leads to the buildup of cells on the surface of the skin which then form silvery scales over red, dry, itchy patches called plaques. The most common form of psoriasis (and the focus of this article) is the abovementioned plaque psoriasis, also referred to as psoriasis vulgaris, accounting for 80-90% of psoriatic patients.
While psoriasis is considered to be a skin disease, it is actually caused by an underlying autoimmune disorder. In this case, T-cells which typically protect the body from infection are activated, causing inflammation and an increase in the rate of cell production. Typically, skin grows in such a way to replace itself around every 30 days. However, with psoriasis the skin replaces itself faster than it can slough off, resulting in silvery plaques over the affected skin.
With plaque psoriasis, the affected area will turn red with inflammation and be covered with silvery dry scales. Typically these lesions form on the elbows, knees, scalp and trunk, though psoriasis can affect any area on the body, including the soft tissue inside of the mouth. When removed, the skin underneath these plaques will often display telltale punctate bleeding points, referred to as the Auspitz sign. Typically, plaques will occur symmetrically on both sides of the body, and can be both itchy and painful. Psoriasis can also affect the joints, with inflammation causing discomfort or even distortion, and is referred to as psoriatic arthritis. Most patients will experience symptoms of psoriasis in cycles, with the affected area flaring up for a time before subsiding or going into full remission.
While the exact cause of psoriasis is unknown, in most cases the condition is hereditary (although multiple genes are involved, so it is often unclear from whom it has been inherited). In some cases, the first outbreak can be triggered by stress, skin injury, or streptococcal infection, such as strep throat. While it is currently accepted that the immune system plays an important role in the overproduction of skin cells leading to psoriasis, the extent of involvement and exact role it plays is still unclear.
Currently, there is no cure for psoriasis, but sufficient management of the condition and symptoms is attainable for most patients. Treatment of psoriasis varies greatly from patient to patient based on the severity of the condition.
The three levels of treatment for psoriasis, ordered by increasing severity of symptoms are:
- Topical application of corticosteroids
- Phototherapy treatments
- Systemic therapy (medications take orally, by injection or by infusion)
Due to the chronic nature of psoriasis, treatments are often combined in various ways and rotated every 6 to 24 months in order to reduce adverse reactions or resistance. Most cases of psoriasis are relatively mild, and simply applying cream or lotion to keep the skin moist can significantly improve the condition.
The following precautions can help minimize the occurrence of flare-ups and maximize the effectiveness of treatment in patients with psoriasis:
- Maintain good health in order to help the immune system fight off infections that can in turn aggravate the skin.
- Be aware of the triggers for psoriasis, most notably stress, dry winter weather, skin injury, smoking and heavy drinking.
- Keep a record of flare-ups, including any relevant information about the preceding circumstances.
- Take good care of the skin, applying lotions, creams and/or emollients daily and avoid scratching the affected area.
- After bathing, pat skin dry. Rubbing can irritate the skin and lead to lesions.
- Avoid bathing in hot water or using harsh soaps, as these can aggravate the affected skin.
For more information:
Psoriasis and Psoriatic Arthritis at the American Academy of Dermatology
Psoriasis Overview at the American Osteopathic College of Dermatology
Psoriasis Overview at the Mayo Clinic
Psoriasis Overview at the New Zealand Dermatological Society
Psoriasis Overview at WebMD
The National Psoriasis Foundation