Swollen and itchy palms may be related to allergic factors or due to insect bite dermatitis, urticaria and other causes. 1. Allergic factors: commonly found in allergic body, when the hands come into contact with yam skin, pineapple skin or washing supplies and other substances, it is likely to cause an allergic reaction, contact dermatitis, it may show palm swelling, itching. 2. Insect bite dermatitis: when the palm area is accidentally bitten by mosquitoes, resulting in mosquito toxin retention in the bitten skin, may induce insect bite dermatitis, resulting in swollen palms, itching, may be accompanied by pain, oozing and other symptoms. 3. Urticaria: usually caused by viral infections, medications, physical stimuli and mental factors, and is prevalent in the palms of the hands, neck, back and other parts of the body, which may cause swelling and itching of the palms of the hands, which may be accompanied by the appearance of skin masses, erythema, etc. The symptoms of hives are usually due to viral infections, medications, physical stimuli and mental factors. Swollen and itchy palms may also be caused by other reasons. If the symptoms persist and cannot be relieved, or if there are other discomforts, it is recommended to consult a doctor as soon as possible to confirm the diagnosis of the causative factors and then give targeted treatment.