Psoriasis is a form of dermatitis and is an autoimmune disorder where there is an increase of skin cells. This condition typically occurs between the ages of 15 and 35. There are five types of psoriasis and each may produce intense inflammation, redness, and scaling of the skin. Psoriasis is most common in the knees, elbows, stomach, feet, hands, and face. Psoriasis can also cause infection, fluid loss, and poor circulation. Genetics may be a predisposed factor with psoriasis, and commonly begins or peaks at ages 23 and 55. There is a significantly lower incidence of psoriasis found in Japanese, Inuit, West African, North American Indian or people of South American Indian descent.
Factors such as physical trauma, bacterial infections, stress, alcohol, dry climates, medications, or weather changes, may exacerbate or trigger psoriasis plaques, especially in areas that were affected before.
Cytokines are cell-signaling protein molecules. Interleukins are cytokines that participate in the regulation of immune responses and inflammatory reactions. Clinical studies have found that patients with psoriasis had elevated levels of pro-inflammatory Interleukin – 6.
Immune Response; T-Cells, Inflammatory Cytokines, Keratinocytes
Keratinocytes are cells that are immunomodulators and are responsible for stimulating inflammation and activating the skin immune cells known as Langerhans cells, in response to injury. With psoriasis, activated immune response T-cells produce inflammatory cytokines that induce hyperproliferation of keratinocytes. This hyperproliferation induced inflammation caused by keratinocytes, results in a profusion of T cells and other immune related cells that interfere with the epidermis, therefore stimulating wound healing cytokines that further exacerbate the condition.
A condition such as guttate psoriasis is a rare form of psoriasis that often appears as a rash of small, light pink bumps, and is commonly found on the torso, arms, and legs. Guttate psoriasis is found with the onset of a strep throat infection, and tends to affect children and individuals under the age of 30. Guttate psoriasis also strikes individuals who have recently recovered from a cold, chicken pox, skin injuries or infections, and may also affect individuals who are experiencing excess stress. A person may develop guttate psoriasis only once, or it may recur with bouts of strep or other infections.
Psoriasis and Disease
Researchers are finding a higher occurrence of diabetes and atherosclerosis (hardening of the arteries) in patients with psoriasis, in comparison to patients without this condition. Catechins are derived from plants, and have potent antioxidant properties, strengthen blood vessels, and help reduce the inflammatory responses in the body. Epigallocatechin is the most abundant catechin found in green tea, and studies have shown that catechins and quercetin reduced atherosclerotic plaques in arteries, and are effective in preventing cancer. Proper diet may be effective therapy for psoriasis patients when preventing atherosclerosis.
Patients with psoriasis may sometime develop psoriatic arthritis. Symptoms include joint pain, weakness, chills, and fever. Without early recognition and intervention, psoriatic arthritis can become disabling.
Treatment for Psoriasis
Treatment for psoriasis ranges from topical applications, including steroids, tazarotene, acetylenic retinoids, and salicylic acid, to phototherapy using UVB and PUVA light therapy, or the use of medications such as methotrexate or cyclosporine.
PUVA Therapy; Methoxsalen, Psoralen
Clinical studies have shown that PUVA therapy, which uses ultraviolet A radiation plus oral methoxsalen, is known to increase the incidence of melanoma. Topical forms of psoralen, a photosensitizing drug derived from plant sources, were shown to be effective to treat psoriasis. Psoralen is commonly taken orally in conjunction with UVA light therapy, which had been associated with an increased risk of non-melanoma skin cancer.
Coal Tar, UVB Radiation
When treating patients with severe psoriasis, the use of coal tar along with increased UVB radiation has been a common form of therapy when treating psoriasis. This therapy requires an average of 20 to 30 treatments, gradually increasing doses of ultraviolet B radiation together with topical application of coal tar. Therapy maintenance consists of lowering the dose of UVB radiation once a week, unless relapse occurs, in which case the treatment frequency must be increased. Both coal tar and UVB radiation therapy have carcinogenic effects.
Methotrexate is metabolized from aminoptenin, and is derived from a class of drugs called anti-metabolites. When used on patients with arthritis, methotrexate was shown to result in clearing of psoriatic plaques. Methotrexate is now approved by the FDA for use in severe psoriasis, as well as rheumatoid arthritis and certain cancers. Although the exact mechanism of action of methotrexate in psoriasis is unknown, it was the first effective systemic medication used in the treatment of psoriasis, and continues to be the standard of therapy against which other therapies are compared. Methotrexate is used in patients with extensive psoriasis that does not respond to topical therapy. When the cumulative dose of methotrexate reaches 1500 mg, patients should be monitored having liver biopsies. Psoriasis patients have an increased risk of developing liver fibrosis and cirrhosis from treatment with methotrexate compared to patients with rheumatoid arthritis treated with similar doses. Side effects may include nausea or diarrhea, and severe hematologic effects decreasing blood cell counts can occur in 25% of patients.
Systemic cytotoxic drugs such as Azathioprine, has been used for treatment of severe psoriasis. However, its use for psoriasis has been limited due to the fact that it causes severe depression of blood formation by the bone marrow and is also associated with an increased risk of malignancies such as lymphoma or squamous cell carcinoma. Thioguanine, a metabolite of Azathioprine, has been shown to cause cell death of activated T lymphocytes. The depletion of activated T lymphocytes from psoriatic plaques resulted in clearing of psoriasis lesions. Thioguanine appears to be successful in patients who could not continue Methotrexate therapy due to liver damage, however, side effects of bone marrow suppression has occurred.
Cyclosporine was found to reduce the number of T lymphocytes in psoriatic lesions, thereby leading to a significant remission of psoriasis lesions. Cyclosporine is indicated in patients who have failed to respond to at least one systemic therapy, or who cannot tolerate other systemic therapies. Cyclosporine therapy has proved remarkably effective with long term administration, although most patients relapsed within 8 to 12 weeks after discontinuation of use, and required higher doses to achieve sufficient improvement. Side effects may include hypertension and renal dysfunction.
Other side effects include the incidence of cancer, and are similar to that of Methotrexate, with about 1% of patients developing malignancies, of which 50% are skin cancers.
Vitamin D Analogue; Calcipotrol
Calcipotrol is a topical Vitamin D analogue used to treat psoriasis. When Calcipotrol is used after PUVA or UVB therapy, a lower dose of radiation may be needed. Side effects include mild irritation, and hypercalcemia may occur if recommended doses are exceeded.
Vitamin A Therapy; Systemic Retinoids
Systemic retinoids can enhance the effects of many other topical and systemic therapies, and are often used in association with topical agents and phototherapy. Oral therapies for psoriasis include those derived from Vitamin A such as Etretinate and Acitretin. Etretinate proved most effective compared to Acitretin for treatment of pustular psoriasis, but has teratogenic (birth defects) potential, and can be found stored in fatty tissue up to two years after use.
Acitretin, a metabolite of Etretinate, is less lipophilic, and is cleared from the body more rapidly than Etretinate, which is considered to pose less teratogenic effects. Acitretin has been approved by the FDA for treatment of psoriasis, although it is less effective than Etretinate, which it has replaced. Long term therapy using systemic retinoids such as Etretinate and Acitretin, requires periodic monitoring for skeletal toxicity.
Topical Retinoids; Tazarotene
A topical retinoid, Tazarotene, was recently introduced for the treatment of psoriasis, which can irritate normal skin, causing pruritis and erythema. Patients who had a successful response to topical therapy, relapsed within three months of discontinuation in 37% of patients. Topical retinoids such as Tazarotene may be enhanced when combined with ultraviolet radiation therapy.
Corticosteroids are steroid hormones naturally found in the body that are involved in stress response, immune response, and regulation of inflammation. Physicians may prescribe corticosteroids to help control inflammation by decreasing levels of pro-inflammatory interleukins in the body, but it is important to know that there are side effects with long term use. It has been found that corticosteroid therapy may only have temporary affects with some patients. Psoriasis plaques have been known to reappear when patients stopped corticosteroid therapy. Long term therapy with topical steroids can cause thinning of the skin, striae, skin discolorations, masking of local infections, and hypopigmentation.
Biologic drugs are protein-based drugs derived from cultured living cells, which are given by injection or intravenous infusion. Biologics target specific parts of the immune system, and are much different from systemic drugs that impact the entire immune system. When treating psoriatic diseases, biologics act by blocking the action of a specific type of immune cells such as T-cells. Biologics works by blocking proteins in the immune system such as TNF-alpha, and pro inflammatory interleukins IL-12 and IL-23, all which play a major role in the development of psoriasis and psoriatic arthritis.
TNF-Alpha, Cytokines, Interleukins
TNF-alpha is a cytokine or a protein that signals the body to create inflammation. With psoriasis and psoriatic arthritis, there is an excess in the production of TNF-alpha in the skin or joints which leads to the rapid growth of skin cells, and damages joint tissue. Intravenous transfusion of biologic drugs blocks the protein TNF-alpha, therefore preventing the inflammatory cycle of psoriatic diseases, and can help reduce the progression of joint damage in patients with psoriatic arthritis. Biologics can also be used and are effective to selectively target proteins or signaling cytokines, (IL-12, IL-23) which are associated with psoriasis inflammation.
Summary; Biologic Therapy
Biologics are prescribed for patients with moderate to severe plaque psoriasis or psoriatic arthritis, and are a viable option for those who have not responded to other treatment options, or who have experienced serious side effects from other forms of therapy. Side effects to biologic therapy include respiratory infections, flu-like symptoms, nervous system disorders, and cancer.
Ceramides; Improve Skin Barrier
In the epidermis, ceramides are known to be an integral part of the extracellular stratum corneum lipid bilayers that constitute the permeability barrier of the skin. Studies have shown that there is a ceramide deficiency in the epidermis with patients who have psoriasis and atopic dermatitis, and an increase of TNF (Tumor Necrosis Factor) in response to cutaneous permeability barrier disruption and wound healing. This TNF signaling generates ceramide, which is an important regulator of proliferation, differentiation, and apoptosis in the skin. Topical ceramides will increase moisture retention in the skin, and encourage a stronger skin barrier.
Hydroxy Acids to Treat Psoriasis
Salicylic acid is the most commonly used keratolytic agent to treat psoriasis, which is recognized by the FDA in low concentration of 1.8% to treat psoriasis. Prescription strengths may range from 2% to 10%, and it is essentially without any side effects. Synergistic therapy using topical salicylic acid with plant derived bioflavonoids, anti-inflammatory agents, and emollients, showed dramatic results when treating psoriasis compared to other therapies with side effects.
Synergistic Therapy; Salicylic Acid, Topical Anti-Inflammatories
Topical anti-inflammatories containing salicylic acid along with botanical extracts showed dramatic improvement is psoriasis plaques. After a six week study, 25 out of 35 patients showed as least 75% improvement, of which nine had complete remission.
Polyhydroxy Acids to Improve Psoriasis
Polyhydroxy acids are effective in cell keratinization and in normalizing the stratum corneum. With a large molecular makeup, polyhydroxy acids can be used on compromised and sensitive skin types. Polyhydroxy acids are beneficial to treat eczema, atopic dermatitis, seborrhea hyperkeratosis, ichthyosis, and rosacea, and can be used to alleviate the scaling of psoriasis plaques, leading to a smoother and softer feel.
Polyhydroxy acids such as lactobionic acid and maltobionic acid are hydroscopic humectants which have antioxidant benefits, and have soothing and healing benefits. Galactose is a component of lactobionic acid and is used in glycosaminoglycans synthesis, cell migration, and is beneficial in wound healing and protein synthesis. Other components such as gluconic acid may assist in the tissue repair process.
The polyhydroxy acid, gluconolactone acid, is a cell nutrient, and a natural component of the skin. Gluconolactone acid also increases skin barrier function, has moisturizing and antioxidant benefits, and can be used as an exfoliant.
Latest Technology to Treat Psoriasis
In clinical studies, the Excimer laser is effective, and can be used to treat psoriasis, alopecia areata, leukoderma, atopic dermatitis, and vitiligo. The Excimer laser is specially designed to produce ultraviolet radiation at a very specific wavelength of 308nm. This wavelength of ultraviolet light is highly effective at treating psoriasis. Excimer laser gives the benefits of narrow band UVB for small treatment areas such as the elbow or knee. Optimal excimer laser therapy consists of 10 to 15 treatments to achieve substantial improvement in plaque psoriasis. With Excimer laser therapy, remission time is generally much longer than topical creams, which makes it optimal therapy when treating psoriasis. Synergistically, topical therapy along with light therapy may prove to have longer lasting results.
Photodynamic Therapy, ALA/PDT
Photodynamic therapy with topically applied 5-aminolevulinic acid or methyl aminolevulinic acid continues to be one of the most exciting new developments in dermasurgery. Photodynamic therapy (PDT) involves the application of a photosensitizing chemical (aminolevulinic acid) to a specific skin lesion. When aminolevulinic acid is applied to the skin, it is converted to a photosensitizer, and when activated by visible light, it releases a toxic effect in the cells, thus destroying dystrophic cells. Photodynamic therapy with topical application of aminolevulinic acid can be effective therapy to treat psoriasis vulgaris, and may be covered by some health insurance companies.
Nutritional Therapy; Improving Immune Function
Psoriasis is an immune disorder, and addressing the immune system must be considered. Although there has been little studies showing the effects of nutritional therapy to treat psoriasis, addressing vitamin deficiencies along with immune therapy may be effective when treating patients with psoriasis.
Increase Carotenoids, Vitamin A
In clinical studies, it was found that patients with psoriasis had a slightly lower than average carotenoid level when compared to healthy patients. Carotenoids are fat soluble pigments (color) found naturally in plants, and serve as antioxidants, prevent free radicals damage of cells, and are important in Vitamin A activity in the body. Nutritional supplements and a diet including carotenoids may prove beneficial when treating psoriasis.
Niacinamide, Vitamin B3
Topical niacinamide is effective to strengthen the skin barrier, and is effective to treat inflammation. Niacinamide also boosts the immune system, improves skin integrity, strengthens the skin barrier and epidermal function, and may be effective to encourage a healthy epidermis with psoriasis patients.
It was also found that severe zinc deficiencies have been associated with hyperkeratotic plaques, which may resemble psoriasis. Zinc has anti-inflammatory properties, and may help with psoriasis lesions.
Selenium is an essential trace nutrient necessary for the normal function of the immune system, and can prevent oxidative stress-induced release of cytokines such as interleukin-10 (IL-10). Interleukin-10 is a multifunctional cytokine that has a crucial role in regulating immune and inflammatory responses.
Selenium is incorporated into proteins to make selenoproteins, which are essential for proper keratinocyte function and skin development. Selenoproteins help regulate thyroid function, and play a role in the immune system. Selenium may reduce inflammation, and encourage proper keratinization of skin cells with psoriasis patients.
Probiotics may be effective when treating autoimmune skin conditions, by strengthening immunity, and balancing the natural micro flora in the body and in the skin.
Vitamins such as D3 have an effect on the immune system, and a deficiency may have an influence in the development and progression of various autoimmune diseases. Vitamin D3 acts as an immune system modulator, preventing expression of inflammatory cytokines and increasing the efficacy of macrophages. It also stimulates anti-microbial peptides which exist in immune cells such as neutrophils, (white blood cells) monocytes, and natural killer cells.
A rapid rise in blood sugar can cause inflammation in the body. Vitamin B6 plays a role in metabolizing proteins, sugars, and fatty acids, and can help control inflammation associated with increased blood sugar levels. In clinical studies, it was found that a deficiency of vitamin B6 can contribute to inflamed skin conditions. Vitamin B6 will help control inflammation, maintain a healthy immune system, and produce antibodies to fight infection.
Shea Oil, Coconut Oil
Shea oil is a vegetable oil that has moisturizing and cell regenerating effects, and was found to benefits psoriasis. Shea oil comes from Karite nuts found on Mangifolia tress in Africa, and contains Vitamins A, E, and F. Coconut oil contains Vitamin E which helps in tissue repair, and can be taken orally and used topically to encourage skin health.
Resorcinol is a dihydroxy phenol that has antiseptic properties, and was found effective in treating psoriasis and eczema.
Psoriasis is an immune disorder where immune response T-cells cause hyperproliferation of keratinocytes causing inflammation and stimulating wound healing cytokines that further exacerbate the condition. Psoriasis can be a debilitating disease and should be monitored by a physician.