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Psoriasis

Diagnosis/Definition

Psoriasis is primarily thought of as a hereditary disorder of the skin with different forms and degrees of severity. Recent research reveals evidence that it is also an autoimmune disorder. The most frequent form is psoriasis vulgaris, which manifests itself as chronic scaling papules and plaques largely located on specific parts of the body: scalp, elbows, forearms, lumbosacral region, knees, hands and feet. The majority of psoriasis manifests itself earlier in life, often in late adolescence. The guttate form of psoriasis (erythematous tiny, drop-like psoriasis papules and small plaques) frequently follows, or is triggered by an upper respiratory infection, particularly Group A beta strep.

Initial Diagnosis and Management

Chronic, lingering plaques are a common presentation. Pruritus is reasonably common (scalp and anogenital areas) and 10% of patients have associated joint pain +/- psoriatic arthritis. Initial diagnosis is generally based on physical exam. Physical exam reveals papules and plaques, sharply marginated with silvery-white scale. Color is usually “salmon pink” to intense erythema. When limited to extremities, lesions are usually bilateral (though not necessarily symmetrical) and favor regions noted above.
Instruct the patient never to rub or scratch the lesions as trauma may stimulate proliferative process (Koebner’s phenomenon) and lead to pinpoint bleeding (Auspitz sign) may be seen if scale is lifted up off of the skin surface.
Topical Steroids – This class is a cost-effective mainstay of therapy. Apply after attempting to loosen / lessen scales by soaking in water. Cream or ointment is preferred for non-hair bearing skin, with solutions, gels, lotion, or foam products best for hair-bearing sites. “Chasing” any topical used with an emollient of choice (Eucerin, Vaseline Petroleum Jelly or other brands of petrolatum, Cetaphil or Moisturel Cream are examples) helps moisten affected site and reduces the amount of topical medication needed. Use of a plastic wrap – cover the area and leave on overnight – may be used in stubborn extremity sites until improved. Beware the risks of steroid overdose, including striae, atrophy, telangiectasis formation and pigment changes, depending on the strength of the steroid and the location of the skin it is applied to. CHCS order sets are also accessible via: m der (list includes both low (“low ‘roids”) and high (“high ‘roids”) topical steroids.
Corticosteroid injection – for small plaques (<4.0 cm), triamcinolone acetonide (10mg/cc) aqueous suspension is injected into the lesion intradermally with small-gauge needle or a DermaJet.
Vitamin D analogues (calcipotriene 0.005%; Dovonex) – Ointment and solution are good topical agents that are not associated with cutaneous atrophy. These are particularly useful in combination with the more potent topical steroids, with maintenance schedule of Dovonex daily on weekdays and the steroid on weekends. Apply to no more than 40% of body and not more than 100 g per week to avoid hypercalcemia risk.
Topical retinoid (Tazarotene cream or gel) – This is another alternative to topical steroids or may be combined with class II topical corticosteroids. This formulation is stronger than Retin-A, has promise, and may be obtained with a New Drug Request if the above options do not give desired outcome. It should be applied to the affected lesions at night.
Hydrocolloid dressing – Use is helpful and effective if left on for 24 to 48 hours. May use class I or II corticosteroid creams without occlusion in conjunction with this method. This method is uncommonly used.
UV phototherapy – With more than 10% involvement of total body surface area (TBSA), it may be used alone or in combination with topical or systemic medicine treatments. Requires motivated patient, appropriate TBSA involvement, and Dermatology consultation.
For the guttate form, test for Group A beta strep (throat culture and ASO titer), and initiate treatment for strep (Penicillin or suitable alternative). In many patients, the guttate psoriasis will resolve until the next strep infection.

Ongoing Management and Objectives

Patient should follow up at 2-4 week intervals initially until regression of lesions becomes apparent.

Indications for Specialty Care Referral

Large involvement of total surface area (greater than 10%).

Lesions that are resistant to conventional therapy or that requires UV light therapy.

Criteria for Return to Primary Care

Psoriasis has resolved and/or a suitable treatment plan has been established. Psoriasis is primarily thought of as a hereditary disorder of the skin with different forms and degrees of severity. Recent research reveals evidence that it is also an autoimmune disorder. The most frequent form is psoriasis vulgaris, which manifests itself as chronic scaling papules and plaques largely located on specific parts of the body: scalp, elbows, forearms, lumbosacral region, knees, hands and feet. The majority of psoriasis manifests itself earlier in life, often in late adolescence. The guttate form of psoriasis (erythematous tiny, drop-like psoriasis papules and small plaques) frequently follows, or is triggered by an upper respiratory infection, particularly Group A beta strep.