The many variants of psoriasis
Erythema, skin thickening, and scales typify most cases, but other patterns exist. Tx choices may differ, depending on how much body surface area is covered.
PRACTICE RECOMMENDATIONS
› Consider guttate psoriasis if small (often < 1 cm) pink scaly papules appear suddenly, particularly in a child who has an upper respiratory tract infection. C
› Document extent of disease using a tool such as the Psoriasis Area and Severity Index, which calculates a score based on the area (extent) of involvement surrounding 4 major anatomical regions. C
› Consider prescribing UV light treatment or a combination of alcitretin and topical corticosteroid if > 10% of the body surface area is involved but joints are not affected. C
Strength of recommendation (SOR)
A Good-quality patient-oriented evidence
B Inconsistent or limited-quality patient-oriented evidence
C Consensus, usual practice, opinion, disease-oriented evidence, case series
Other systemic agents—for individuals who cannot tolerate the biologic agents—include acitretin, azathioprine, mycophenolate mofetil, and cyclosporine.15,17
Paradoxical psoriatic reactions
When a psoriatic condition develops during biologic drug therapy, it is known as a paradoxical psoriatic reaction. The onset of de novo psoriasis has been documented during TNF-α inhibitor therapy for individuals with underlying rheumatoid arthritis.23 Skin biopsy reveals the same findings as common plaque psoriasis.
Using immunosuppressive Tx? Screen for tuberculosis
Testing to exclude a diagnosis of latent or undiagnosed tuberculosis must be performed prior to initiating immunosuppressive therapy with methotrexate or a biologic agent. Tuberculin skin testing, QuantiFERON-TB gold test, and the T-SPOT.TB test are accepted screening modalities. Discordance between tuberculin skin tests and the interferon gamma release assays in latent TB highlights the need for further study using the available QuantiFERON-TB gold test and the T-SPOT.TB test.24
CORRESPONDENCE
Karl T. Clebak, MD, FAAFP, Penn State Health Milton S. Hershey Medical Center, Department of Family and Community Medicine, 500 University Drive, Hershey, PA 17033; kclebak@pennstatehealth.psu.edu.
