Overview: Psoriasis

• Psoriasis is a chronic inflammatory skin disease characterized by abnormal differentiation and hyperproliferation of the epidermis.

• Clinically, it manifests as redness and scaling. Psoriasis is fairly common, affecting approximately 2% of the general population.

• It is more common in white persons and has a bimodal age distribution, with peak onsets between 20 and 30 years and between 50 and 60 years. The cause of psoriasis is multifactorial, with both genetic and environmental components.

• A family history can usually (but not always) be elicited If one parent has psoriasis, the risk of a child's having the disorder is approximately 14%. This figure jumps to 41% if both par-ents have the disorder. Several human leukocyte antigens (HLAs Istocompatibility antigens)) have been associated with psoriasis, including HLA-B13, HLA-B17, HLA-B27. HLA-Cw6, and HLA-DR7.

• The strongest connection lies with HLA-Cw6, which is associated with earlier-onset dis ease that is more difficult to treat. Finally, several genetic loci have been linked to the development of psoriasis. Currently, PSORSI is considered the major gene associated with psoriasis.

Important points to consider

• The Koebner phenomenon is when skin trauma or imitation triggers a skin reaction such as a psoriatic plaque. Treatment of itching is important because scratching can trigger flares.

• Oatmeal baths can be made by placing whole oats in a blender and grinding to a fine powder. Water is added to a half cup of the oat flour to make a lose slurry that can be added to a bath. A thicker paste can be made and patted onto psoriatic lesions as a poultice.

• Milk thistle can be protective against hepatotoxicity in patients using methotrexate to control psoriasis.

• The benefits of phototherapy and topical vitamin D analogues in the treatment of psoriasis also warrant 25-hydroxyvitamin D serum screening to make sure adequate oral supplementation i is provided to maintain levels between 40 and 60ng/mL

• Improving stress levels may enhance results from more conservative or traditional therapies.

• Assessment of traditional Chinese medicine (TCM) as system is very difficult within a Westem framework. The classification of point 1 of of view, disease in TCM is based on a different and because each patient is it is evaluated and treated individually with various combinations of herbs and acupuncture, creating standardized protocols to measure treatment outcomes is difficult.

Prevention Prescription

• We currently do not have a way to prevent peoriasis. Although some situations are known to exacerbate psoriasis, flares are often unpredictable. Some things patients with psoriasis can do include the following Maintain a balanced lifestyle

• Minimize stress. Maintain a stable weight.

• Avoid alcohol overuse.

• Avoid tobacco

• Eat a well-balanced diet.

• Treat skin infections early.

• Avoid medications known to exacerbate psoriasis (Le, lithium, beta blockers, antimalarials, interferon, and rapid tapering of systemic corticosteroid dosage).

Integrative therapeutics review

General Measures

• Gentle skin care: Avoid hot water for bathing and use gentle cleansers and emollients and colloidal oatmeal.

Phototherapy

• Narrow-band ultraviolet B or ultraviolet B

• Ultraviolet A alone or with psoralen (PUVA)

• Climatotherapy and balneophototherapy

Nutrition and Supplements

• Antiinflammatory diet. See Chapter 86. The Antiinflammatory Diet.

• Fish oil or oily fish: This is also useful as an adjuvant to decrease side effects of systemic retinoids and cyclosporine. Consider 2 to 3 g/day. Zinc: No good evidence has indicated a benefit in psoriasis; however, some clinicians do report a benefit. The dose is 15 to 30 mg/day.

• Inositol: This may be useful in patients with lithium-induced psoriasis. The dose is 6 g/day. with monitoring of psychiatric disease in patients with bipolar disorder.

Topical Botanicals

• Capsaicin for itching: A 0.025% or 0.075%

• cream is applied three or four times/day. Patients may experience stinging or burning during initial applications. Aloe vera: This may help decrease scaling and redness.

• Glycyrrhetinic acid 1% to 2% formulation: This may enhance the effect of topical steroids by inhibiting their degradation.

Systemic Botanicals

• Curcumin: The effective dose is unclear. One study looked at 150 mg three times a day.

• Milk thistle. The dose is 140 mg (70% silymarin) two to three times/day. It is best used as a hepatoprotective agent in patients taking hepatotoxic medications.

Topical Pharmaceuticals

• Keratolytics, to decrease scale and plaque thickness

• Salicylic acid (2% to 10%) twice daily

• Urea (up to 40%) twice daily

• Alpha-hydroxy acids (glycolic and lactic acids) twice daily

• Tar: 2% to 20% preparations

• Anthralin: 0.5% to 1% preparation applied for 10 to 30 minutes once or twice daily, to protect normal skin from irritation

• Calcipotriene (Dovonex): 0.005% cream, lotion, or ointment twice daily, limited to no more than 100g/week

• Tazarotene gel (Tazorac): 0.05% to 1% gel applied at bedtime

• Topical steroids: See Table 69-4. Clinician should pay attention to the location treated and watch for side effects.

Systemic Pharmaceuticals

• Methotrexate: 10 to 15 mg/week; single weekly dose or divided into three doses given 12 hours apart

• Cyclosporine: started at 5.0 mg/kg/day, with dosage tapered by 0.5 mg/kg/day to the lowest required dose

• Acitretin (Soriatane): 10, 25, or 50 mg daily

• Biologic immune response modifiers:

• Alefacept (Amevive): 15mg/week intramuscularly for 12 weeks

• Etanercept (Enbrel): 50 mg once or twice a week subcutaneously

• Efalizumab (Raptiva): 1 to 4 mg/kg once a week subcutaneously

• Infliximab (Remicade): 5 mg/kg over 2 to 3 hours intravenously at weeks 0, 2, and 6 and then every 8 weeks thereafter.

• Ustekinumab (Stelara): 45 or 90 mg as a subcutaneous injection at weeks 0 and 4 and then every 12 weeks thereafter

Mind-Body Therapy

• Meditation: Great for stress reduction or minimization

• Hypnosis: Most potential benefit for hypnotizable patients Therapies to Consider

• Traditional Chinese medicine: Please see the text Dermatology in Traditional Chinese Medicine, by Xu Yihou, for more detailed and complete information on and understanding of traditional Chinese medicine.

• Homeopathy

Key Web Sources

• www.medicalacu puncture.org

• www.homeopathic-directory.com

• http://homeopa thy.org/specialty-board.html

• www. hanp.net

• www.homeopa thy.org

• www.psoriasis.org

• www.mayoclinic.com/health/psoriasis/DS00193

• http://www.aad.org/education-and-quality-care/medical-student-core-curriculum/psoriasis/