I have had this very problem for years now. The doctors can not tell me what it is and give me some kinda of itching cream and send me on my way. THESE NEVER WORK. What I have found is that these occur in the summer time for me. The little blister like rash ITCH so bad that i will scratch them until they hurt. No need for this now. I have found that if I soak my hands in some Epsom salt and Ice cubes twice for about 20 min a day once I see symptoms of them I can usually get rid of them before they get bad! Heat seems to irritate and inflame the blisters more.
Hello,
The symptoms are suggestive of dyshidrotic eczema. Wash the areas several times with fresh water. Do not use any cosmetic products at the sites. You can apply some calamine lotion at the rash as it will help in soothing the skin. You can take some OTC oral antihistamine medications like Benadryl or Claritin and see if it helps.
For mild-moderate eczema a weak steroid may be used, whilst more severe cases require a higher-potency steroid. Eczema can be exacerbated by dryness of the skin. Use good quality moisturizers to prevent moisture loss from the skin.
If still the symptoms do not improve then please get a clinical examination done by a dermatologist. I hope it helps. Take care and please do keep us posted in case you have any additional doubts. Kind regards.