What should I look for in an OTC psoriasis shampoo?

Sal acid and Tar. Psoriatic scalp often is also colonized by a common yeast called pityrosporum ovale, which is the same yeast that causes dandruff. Treatment involves controlling yeast proliferation and exfoliating. Otc shampoos for dandruff generally helps with psoriasis as well such as head and shoulder, neutrogena t-gel, neutrogena t-sal, dhs, or Nizoral (ketoconazole) shampoos.