The large blisters on the feet are considered to be friction, contact dermatitis, insect bite dermatitis and so on. 1. Friction: If you choose the wrong shoes or walk a lot for a long time, it will cause friction on the skin of the feet to appear large blisters, usually accompanied by painful symptoms. 2. Contact dermatitis: contact dermatitis is an acute or chronic inflammation of the skin after contact with certain exogenous substances, and irritation, allergy and other factors, if the acute onset of pimples, papules, severe blisters and blisters, blisters with tense walls and clear content. 3. Insect bite dermatitis: insect bite dermatitis is caused by insect bites or venomous sap stimulation, each person’s physique is different, the type of insect is different, the specific performance varies, if it is caused by mite bites, there will be pimples, pimples and ecchymosis, occasionally there will be large blisters. There may be other reasons for the blisters growing on the feet, it is recommended to go to the hospital for a detailed examination, to clarify the cause of the disease after standardized treatment, to avoid delaying the condition.