An allergen absorbent and blocking aerosol composition for topical application to the skin comprises a highly activated organophilic clay of the smectite type, ion exchanged with a quaternary ammonium compound having aryl or alkyl groups in the range of from 10 to 22 carbon atoms, and a vehicle comprising one or more long-chain hydrocarbons or volatile silicone oils. The composition is preferably in the form of an aerosol composition additionally comprising an aerosol propellant. The composition is applied to the skin, preferably by spraying, to block and absorb the allergenic oils of toxic plants such as poison ivy and the like.