PDE4A and psoriasis vulgaris: Roflumilast is approximately 25–300-fold more potent than oral apremilast and topical crisaborole in vitro, which are the two other PDE4 inhibitors approved for dermatologic conditions.7 Roflumilast cream (0.15%) has been approved for those age 6 and over for atopic dermatitis; roflumilast (0.3%) cream is approved for those 12 and older for plaque psoriasis; and roflumilast foam (0.3%) has been approved for age 9 and over for seborrheic dermatitis.