A process for treating psoriasis and similar skin disorders whereby two formulations are used. The first formulation in a cream, gel, lotion, foam or ointment base is used two or more times daily, and contains effective amounts of (but not limited to) methylcobalamin, niacinamide, select cetylated fatty esters, and antioxidants. This formulation is used to suppress immunoproliferative and inflammatory mediated activities that play significant roles in hyperproliferation and erythema. The second formulation, used selectively to reduce plaque thickening and to reduce irritation, contains effective amounts of (but not limited to) salicylic acid and select cetylated fatty esters in a cream, gel, lotion or ointment base, with pH optimized for exfoliation properties. The unique combination of salicylic acid (or other β- or α-hydroxy acid) and cetylated fatty esters provides keratolytic activity while suppressing irritation and inflammation. The invention for this novel two-step polytherapy, are disclosed including the mode of sequential administration.