Myth: Pick Psoriasis Scales to Remove Them
Patients may be inclined to pick psoriasis scales that appear in noticeable areas or on the scalp. However, they should be counseled to avoid this practice, which could cause an infection. Instead, Dr. Steven Feldman (Winston-Salem, North Carolina) suggests putting on an ointment or oil-like medication to soften the scale. “Almost any kind of moisturizer will change the reflective properties of the scale so that you don’t see the scale,” he advised. He also suggested descaling agents such as topical salicylic acid or lactic acid. His patient education video is available on the American Academy of Dermatology website should you wish to direct your patients to it.
Because salicylic acid is a keratolytic (or peeling agent), it works by causing the outer layer of skin to shed. When applied topically, it helps to soften and lift psoriasis scales. Coal tar over-the-counter products also can be used for the same purpose. The over-the-counter product guide from the National Psoriasis Foundation is a valuable resource to share with patients.
I agree that it is very important to treat scale very gently. In addition to risk for infection, picking and traumatizing scale can lead to worsening of the psoriasis. This is known as the Koebner phenomenon. The phenomenon was first described by Heinrich Koebner in 1876 as the formation of psoriatic lesions in uninvolved skin of patients with psoriasis after cutaneous trauma. This isomorphic phenomenon is now known to involve numerous diseases, among them vitiligo, lichen planus, and Darier disease.
—Jeffrey M. Weinberg, MD (New York, New York)