Psoriasis
Understanding Psoriasis
Psoriasis is a chronic (long-lasting) skin disease characterized by scaling and inflammation. Scaling occurs when cells in the outer layer of skin reproduce faster than normal and pile up on the skin’s surface.
Psoriasis affects 2 to 2.6 percent of the United States population, or almost 5.8 to 7 million people. It occurs in all age groups and about equally in men and women. People with psoriasis may suffer discomfort, restricted motion of joints, and emotional distress.
When psoriasis develops, patches of skin thicken, redden, and become covered with silvery scales. These patches are sometimes referred to as plaques. The areas of involvement frequently itch or burn, and the skin may crack. Psoriasis most often occurs on the elbows, knees, scalp, lower back, face, palms, and soles of the feet. The disease also may affect the fingernails, toenails, and the soft tissues inside the mouth and genitalia. About 10% of people with psoriasis have joint inflammation that produces symptoms of arthritis. This condition is called psoriatic arthritis.
Psoriasis is not contagious in any way. It is not possible to “catch” psoriasis by touching a person afflicted with it.
What causes psoriasis?
Research indicates that psoriasis may be a disorder of the immune system. The immune system includes a type of white blood cell, called a T cell that normally helps protect the body against infection and disease. Scientists now think that psoriasis is related to an abnormal immune system that deposits too many T cells in the skin. These T cells trigger the inflammation and excessive skin cell reproduction. The rapidly dividing skin cells push their way to the surface of the skin where they form plaques.
In some cases, psoriasis is inherited. Researchers are studying large families affected by psoriasis to identify a gene or genes associated with the disease. (Genes govern every body function and determine inherited traits that are passed from parent to child.)
Are there treatments for Psoriasis?
There are a few OTC topical drugs for psoriasis with either coal tar or salicylic acid as active ingredients, but these are relatively ineffective. There are many topical prescription drugs for psoriasis, including topical corticosteroids, and vitamin D analogues. While helpful, the corticosteroids typically can’t be used long-term because of side effects, and their effectiveness is temporary. There are newer “biologics” which are injectable recombinant protein-based drugs that act specifically to inhibit various immune cell functioning. One of the primary targets of the “biologics” is an inflammatory cytokine (a type of hormone) called TNF-α. While effective, these types of therapies require frequent injections, have been shown to reduce the immune system, and are expensive.
DermaMedics has developed a topical formulation that contains 2% salicylic acid, the OTC approved drug for psoriasis as well as Therosol and a related compound, Therosol-C. This product is unique because DermaMedics scientists have developed a method for solubilizing the salicylic acid directly into a gentle, moisturizing silicone based serum, which glides on the skin. And unlike typical emulsifier-based lotions, which can irritate the skin, this silicone based product does not damage the skin’s surface or cause any discomfort. The presence of Therosol in the product calms and soothes the skin, and helps the skin repair itself. This product is currently undergoing clinical testing.
Clinical Treatment of Psoriasis
Psoriasis is a chronic, autoimmune disease that appears on the skin. It occurs when the cells of the immune system inappropriately produce hormone-like signals that speed up the growth cycle of skin cells. Psoriasis is not contagious. There are five types of psoriasis: plaque, guttate, inverse, pustular and erythrodermic. The most common form, plaque psoriasis, appears as raised, red patches or lesions covered with a silvery white buildup of dead skin cells, called scale. Psoriasis can occur on any part of the body.
There are many topical OTC and prescription drugs available for treating the symptoms of psoriasis, but there is no cure for the disease. Of the products available to treat psoriasis, none of the OTC drugs, which contain such FDA approved “drugs” as coal tar, are particularly effective in relieving the itching or reducing the number or severity of plaques. Prescription topical drugs include corticosteroids (clobetasol, betamethasone), vitamin D analogues (e.g. Dovonex), or topical vitamin A derivatives (Tazorec). All are somewhat effective short term, and all have some negative side effects. Oral medications include cyclosporine and methotrexate. Phototherapy is also used to treat mild psoriasis. More recent drugs developed for treating moderate to severe psoriasis include “biologics” which specifically target components of the immune system known to be involved in psorsiasis. These include monoclonal antibodies to block T-cell receptor activation (Amevive) and antibodies that block TNF-alpha, an inflammatory cytokine of the immune system (Enbrel). Although these new “biologic” injectables are effective, they are expensive, and because they are strongly immunosuppressive, they can markedly increase the risk of infection.
DermaMedics’ approach for developing effective technologies for addressing inflammatory skin problems is based on: 1) developing topical rather than systemic treatments so that the therapy is confined to the site of disease and not spread throughout the circulatory system, and 2) developing topical formulations that funciton to “reset” the immune system to a basal state, rather than strongly suppressing its ability to function at all. During DermaMedics drug screening program, several botanically derived chemical compounds were discovered that can: 1) reduce the production of TNF-alpha by skin and immune cells, and 2) reduce the ability of TNF-alpha to activate target cells. Interestingly, many of these compounds are actually approved food flavoring agents that are found on the EAFUS list (everything added to food, U.S.), and which have been widely used to flavor candies, cakes and ice cream for over 50 years. By identifying naturally occurring compounds that are safe and gentle to the skin, DermaMedics scientists believe that it is possible to develop topical products that effectively improve skin appearance without increasing the risk of skin infections or other medical problems caused by suppressing the body’s immune system.
DermaMedics has developed a novel topical psoriasis treatment serum that contains Therosol® as well as 2% salicylic acid, the FDA approved OTC drug for psoriasis. Because this silicone based serum is so gentle, it can be applied to severly abraded skin without causing any discomfort. To investigate the efficacy of this silicone based serum on psoriasis, DermaMedics conducted a small clinical study. The investigator for this clinical investigation was Dr. Zoe Draelos, a highly respected and world-recognized dermatologist. For the study, 20 patients with mild to moderate psoriasis were evaluated for psoriasis using an ordinal 6 point scale. Evaluations were conducted at the start of the study (baseline), at 2 weeks, and at 4 weeks. The results at 4 weeks are shown in the bar graph below. The statistical evaluation of the data was performed using a two-tailed Mann-Whitney test.
After 2 weeks of serum use, the clinical investigator’s evaluation showed a statistically significant improvement in erythema (p= 0.016) and scaling (p=0.018) which led to a statistically significant decrease in overall severity (p=0.022). This improvement continued on into week 4 where the investigator found statistically significant improvements in erythema (p=0.008), scaling (p=0.008), excoriation (p=0.021), induration (p=0.023) and overall improvement (p=0.002). This high degree of statistical significance in such a small population of patients indicates that the topical serum formulation is highly effective in reducing the severity of psoriasis.
The patient evaluation of the serum product was essentially the same as the investigator’s assessment. Patient evaluations showed statistically significant improvements in redness (p=0.017), peeling (p=0.007), roughness (p=0.004), itching (p=0.054) and overall severity (p=0.008) in just 4 weeks of use.
DermaMedics is now developing this serum into an OTC topical product for use in treating psoriasis. The serum will contain 2% salicylic acid in an extremely gentle silicone base which calms the skin, prevents moisture loss, speeds exfoliaton, and reduces the symptoms of psoriasis.