The presence of significant itching in the palmar region of the left hand unilaterally requires careful observation of the skin changes at the site of the itching. If the appearance does not have any abnormality, purely itching-based, consider the possibility of limited pruritus. You can choose to take oral cetirizine tablets, but also can be in the local topical spray compound chlorhexidine acetate spray, there is a very good role in relieving itching. If the itchy palms of the hands appear obvious keratinized hyperplasia, consider the possibility of chronic keratinized eczema. It is more frequent in the hands and is related to long-term contact with acidic and alkaline liquids. It is recommended to choose to use fluticasone propionate cream, with compound lactic acid cream has certain therapeutic efficacy. If you can see obvious blisters scattered in the palm of the hand, it is possible to consider sweat blister eczema, but also may be a fungal infection caused by ringworm, it is recommended to go to the local hospital to do a fungal test to clarify the diagnosis.