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After completing this case study, students should be able to:

  • Describe the pathophysiology and clinical presentation of plaque psoriasis.

  • Discuss the appropriate use of topical, photochemical, and systemic treatment modalities including biologic agents for psoriasis, based on disease severity.

  • Compare the efficacy and adverse effects of systemic therapies for psoriasis, including first-line standard therapies (methotrexate, acitretin, cyclosporine), second-line therapies (azathioprine, hydroxyurea, sulfasalazine), and the biologic agents (TNF-alpha inhibitors, ustekinumab, IL-17 inhibitors, and IL-23 inhibitors).

  • Select appropriate therapeutic regimens for patients with plaque psoriasis based on disease severity and patient-specific considerations such as organ dysfunction.

  • Educate patients with psoriasis about proper use of pharmacotherapy, potential adverse effects, and necessary precautions.


Chief Complaint

“Nothing is helping my psoriasis.”


Gerald Kent is a 50-year-old man with a 27-year history of psoriasis who presented to the outpatient dermatology clinic 2 days ago with another flare-up of his psoriasis. He was admitted to the inpatient dermatology service for a severe flare of plaque psoriasis involving his arms, legs, elbows, knees, palms, abdomen, back, and scalp (Fig. 110-1).

FIGURE 110-1.

Plaque psoriasis. This papulosquamous skin disease is characterized by small and large erythematous papules and plaques with overlying adherent silvery scale. (Adapted with permission from: Yancey KB, Lawley, TJ. Approach to the patient with a skin disorder. In: Jameson J, Fauci AS, Kasper DL, et al, eds. Harrison’s Principles of Internal Medicine. 20th ed. 2018. New York, NY: McGraw-Hill Education; 2018. Accessed April 12, 2019.)

The patient was diagnosed with plaque psoriasis at age 23. He initially responded to topical therapy with medium-potency topical corticosteroids, later to calcipotriol. He subsequently required photo-chemotherapy using psoralens with UVA phototherapy (PUVA) to control the condition. PUVA eventually became ineffective, and about 10 years ago he was started on oral methotrexate 5 mg once weekly. Dosage escalations kept the condition under fairly good control for about 5 years. Flare-ups during that period were initially managed with SCAT (short-contact anthralin therapy), but they eventually became more frequent and lesions were more widespread despite increasing the methotrexate dose. A liver biopsy performed about 5 years ago showed no evidence of fibrosis, hepatitis, or cirrhosis.

After requiring two SCAT treatments in a 4-month period, along with methotrexate 25 mg once weekly orally (given as two doses of 12.5 mg 12 hours apart), a change in therapy was considered necessary at that time. Because he was receiving the maximum recommended methotrexate dose and had already reached a lifetime cumulative methotrexate dose of 2.2 grams, he was changed to a cyclic regimen ...

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