Skin itching and chewing-tongue on trainer, what is wrong with me?

my husband has rashes & itchy skin on the legs and on belly for 5 years, he went through all kind of skin tests and taking different medicines but stills having it. Recently, he said that every night while doing dishes (about 2 hrs after having dinner) he starts having rashes and itchy and thought that it causes by the dry stuff in our open pantry. Sounds crazy huh!?! does anyone has same kind skin allergy that would like to share. Many thanks in advance.