What Causes Itching, Redness And Swelling On Soles?

Hi. for the past two months, i've been having sudden bouts of itchy feet swollen and red in some parts of the soles. This also happens with palms/lower arms. The symptoms usually go away in a day. sometimes the symptoms are accompanied by tightening of the throat - makes it difficult to swallow. I've been tested negative for angioedema. Food allergy tests came back negative too. I'm otherwise healthy; only concerns are higher cholesterol and varicose veins. What else could it be? Thanks. Dmitri