Abstract: This invention defines novel compositions that can be used for clinical treatment of a class of chronic inflammatory diseases. Increased generation of carbonyl substances, namely aldehydes and ketones, occurs at sites of chronic inflammation and is common to the etiologies of all of the clinical disorders addressed herein. Such carbonyl substances are cytotoxic and additionally serve to perpetuate and disseminate the inflammatory process. This invention defines use of compositions, the orally administered required primary agents of which are primary amine derivatives of benzoic acid capable of covalently reacting with the carbonyl substances. p-Aminobenzoic acid (or PABA) is an example of the required primary agent of the present invention. PABA has a small molecular weight, is water-soluble, has a primary amine group which reacts with carbonyl-containing substances and is tolerated by the body in relatively high dosages for extended periods.