This application relates to a material which is suitable for the treatment of atopic disease, non-atopic eczema or psoriasis. The material can be extracted from a freeze-dried decoction of a mixture comprising the following Chinese herbs: Radix Ledebouriella, Fructus Tribuli, Herba Potentilla chinensis, Caulis Clematis armandii, Radix Rehmannia, Radix Glycyrrhiza, Radix Paeonia rubra, Cortex Dictamni radicis, Herba Lopatheri, Spica Schizonepetae. The material comprises one or more of those components present in the freeze-dried decoction which run with Rf values in the ranges 0.00 to 0.100, 0.167 to 0.300, 0.400 to 0.533, 0.700 to 0.833 or 0.900 to 0.967 if the freeze-dried decoction is diluted in aqueous solution and subjected to chromatography on a Whatman 2 cms.times.55 cms.times.3 mm cellulose strip for 10 hours using a solvent mixture of butanol, ethanol and water in the proportions 4:1:1.