Psoriasis Yale 041409

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					                                    PSORIASIS
             H. Compton Gift, M.D., M.P.H. and Stephen Holt, M.D., M.S.
                                     Week 19
Educational Objectives:

          1.   Be able to differentiate psoriasis from other dermatologic conditions
          2.   Describe the available treatment modalities for psoriasis
          3.   Know the indications for referral to a specialist
          4.   Be able to identify the quality of life issues in the psoriatic patient

CASE ONE:

A 35-year-old male with a 5-year history of psoriasis comes in complaining that he recently
lost his job as a bartender due to his “repulsive” skin lesions. His father had psoriasis and
was similarly discriminated against as a chef. His physical exam is remarkable for typical
psoriatic plaques involving the scalp and intertriginous sites. Examination of his nails
reveals pitting, with some onycholysis. He comes to you, desperate for treatment.


Note to Preceptors:

It might be helpful to locate the clinic’s copy of Fitzpatrick’s Color Atlas (or a comparable
text) prior to today’s conference, so that you have it available as a visual aid.

Questions:

                  1. How can you clinically distinguish psoriasis from other skin
                     conditions? How is it diagnosed?
                     In most cases, psoriasis is a clinical diagnosis based on history and
                     physical exam. The most common patterns include chronic plaque
                     psoriasis, guttate psoriasis, pustular psoriasis, and erythrodermic
                     psoriasis, with plaque psoriasis being the most common. Classically, the
                     lesions are well-demarcated patches with overlying silvery scale on an
                     erythematous bed. Commonly affected skin regions include the elbows,
                     knees, lower back and scalp. In some cases, skin flexures including the
                     submammary, axillary, and intergluteal folds are involved. In addition to
                     the classic skin findings, psoriasis is often associated with nail bed
                     findings (e.g. pitting, onycholysis, and subungual hyperkeratosis) and
                     psoriatic arthritis (5-20% of patients). Psoriasis should be differentiated
                     from seborrheic dermatosis, discoid lupus, mycosis fungoides (i.e. CTCL),
                     and tinea infections. Biopsy is seldom necessary to make the diagnosis.
2. What factors may exacerbate his underlying condition?
   Several factors are known to worsen psoriasis. Drugs that are the most
   common offenders include lithium, beta-blockers, NSAIDS such as
   indomethacin, antimalarials, systemic interferon alpha, alcohol, rapid
   tapering of systemic steroids, ACE inhibitors, and terbinafine.
   Infections, both bacterial and viral, have long been associated with
   exacerbation (e.g., post streptococcal flares of guttate psoriasis and
   worsening of psoriasis with HIV infection).

   Additional aggravating factors include mechanical injury (Koebner
   phenomenon), sunburn, and stress. Symptoms also tend to worsen in the
   winter-time.

3. Describe the topical therapies that are available. What are the
   limitations of these treatments? Which are the most effective?
   Numerous topical therapies are available, and primary care physicians
   should feel comfortable instituting treatment in patients with mild-
   moderate psoriasis. Seventy to eighty percent of patients with psoriasis
   can be managed with topical therapy alone, although none of the currently
   available treatments are curative.

   Possible treatments include emollients, topical steroids, Calcipotriene
   (Dovonex), coal tar products, Tazorotene (Tazorac), and Anthralin
   (Anthro-Derm). Recent head-to-head trials (of all the aforementioned
   therapies except emollients) have failed to demonstrate superiority of any
   one class over another (although there may be some added benefit to high
   potency topical steroids). Many of them can be used in combination to
   limit side effects.

   Emollients - offer hydration, keeping the psoriatic skin soft and
   minimizing itching. Products containing lactic acid or alpha-hydroxy acid
   can be irritating to inflamed or broken skin.

   Topical Steroids – The mainstream of topical treatment. Their anti-
   inflammatory, antiproliferative, and immunosuppressive properties are
   thought to be their primary mechanism of action. The potency of the
   steroid prescribed should depend upon the location and thickness of the
   lesions, e.g., hydrocortisone 1% cream for face and intertriginous areas,
   and the more potent fluocinonide 0.05% for the scalp. Potential side
   effects include skin atrophy, telangiectasias, and acne eruption. Usually
   high-potency steroids are used initially to control a flare up, followed by
   lower potency steroids for maintenance. Penetration of topical steroids
   can be enhanced with application of occlusive dressings.

   Calcipotriene (Dovonex) –A Vitamin D analogue available in cream,
   ointment, or solution that inhibits the growth and differentiation of
   keratinocytes. Doses greater than 100 gm/wk may result in hypercalcemia
   and skin irritation. Has a slow onset of action.

   Coal Tar – A time-honored treatment first described by Goeckeman in
   1925. It is thought to have an antiproliferative effect. Products are
   available over the counter in the form of shampoos, creams, and oils. It is
   most effective when used in combination with topical steroids. Quite
   messy and malodorous!

   Anthralin - Derived from wood tar, available in oil, ointment, cream, and
   solutions. Like coal tar, can lead to staining of clothing, skin, bathtub,
   etc.

   Tazarotene – A topical retinoid which slowly helps to normalize the
   proliferation and differentiation of keratinocytes. Effective in the
   treatment of mild to moderate plaque psoriasis. Classified as a pregnancy
   category X drug, and its use should be avoided in women of childbearing
   age.

   Of note, adherence to topical therapy regimens is extremely poor (<50%)
   due to the significant limitations described above.

4. At what point would it be appropriate to refer him to a specialist?
   Referral is recommended when there is uncertainty as to the diagnosis or
   failure to respond appropriately to topical therapy after three months.
   Extensive, generalized psoriasis, significant disability, or lesions in
   delicate locations (e.g. face, genitals) should also precipitate referral.
   Generally speaking, if more than 10% of the body surface area is
   involved, the patient will likely need systemic therapy, and thus a
   specialist.

5. Discuss other available therapeutic modalities.
   As stated above, systemic therapies for generalized psoriasis are best
   administered in consultation with a dermatologist.

   Established regimens include phototherapy (PUVA) in combination with
   systemic agents (e.g., cyclosporine, retinoids, methotrexate, etc.) or
   topical agents. PUVA therapy uses oral psoralen to sensitize the patient’s
   skin to UVA light, thus intensifying the treatment.

   Novel modalities approved by the FDA include “biologic” treatments
   (e.g., monoclonal antibodies, cytokines, and fusion proteins) that
   specifically target key mechanisms in the pathogenesis of psoriasis.
   Examples include Etanercept (Enbrel), Infliximab (Remicaid), Efalizumab
   (Raptiva), and others. These agents work by either inhibiting T-cell
   activation, leukocyte recruitment, or by directly inhibiting TNF.
                 6. What other possible issues should be addressed in this patient?
                    a. Assess for joint pains. All patients with evidence of psoriatic arthritis
                    should be referred to a rheumatologist.

                      b. Psychosocial effects. Patients suffer not only from the physical effects
                      of the skin manifestations themselves, but also from the psychological
                      impact of having a disfiguring skin disease. Moreover, the treatments
                      themselves are the source of significant morbidity, from the side effects of
                      the medications to the extreme inconvenience of their daily application.
                      Indeed, studies have shown that the psychological impact of psoriasis on
                      quality of life measures is equal to or greater than the impact from
                      diabetes, rheumatoid arthritis, or cancer. Informing patients and their
                      families that psoriasis is not contagious may lessen the stigma of the
                      disease; physically touching the skin lesions can be particularly beneficial
                      and communicates to the patient that they are not contagious.

                      Treating the psychosocial aspects of the disease requires recognition of
                      both the attitude of the general population, which may result in not so
                      subtle discrimination, and the patient’s perspective. Patients should be
                      referred to the National Psoriasis Foundation website for additional
                      psychosocial support, educational materials, etc.

                 7. Bonus Question: What is the currently accepted theory regarding the
                    pathophysiology of psoriasis?
                    Dysregulation of T-cells and upregulation of TNF-, leading to
                    recruitment of other pro-inflammatory immune cells, hyperproliferation of
                    epidermal keratinocytes, and hyperkeratosis.

Primary References:

   1.     Smith CH, Barker JN. Psoriasis and its management. British Medical Journal. 2006.
          333:380-384.
   2.     Jobling R. Psoriasis. British Medical Journal. 2007. 334:953-954.
   3.     Schon MP, Boehncke WH. Psoriasis. New England Journal of Medicine. 2005.
          352:1899-1911.

Additional References:

   1.     Cayce KA, et al. A red, scaly rash: How to recognize and treat psoriasis. JCOM.
          2004. 11:463-474.
   2.     National Psoriasis Foundation website: www.psoriasis.org
   3.     Hunter J, Savin J, and Dahl M. Clinical Dermatology. 3rd ed. Malden, MA:
          Blackwell Science Ltd; 2002.

				
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