Herpes Simplex - it could be this as well. Is it bumpy and splotchy like hives or are the blisters small and clear, itchy until you touch them and then they burn like acid? If the second is the case, have your doctor check them out, you might have herpes simplex. Don't freak out - it isn't an STD. It took awhile for my doctor to identify it. I keep a full bottle of Acyclovir and pop some when the blisters start to appear. Usually within a day or two (if I caught it right away) the blisters go away. My blisters usually start between my fingers and one spot on my shoulder.
Hello,
For sun allergy, apply a good sunscreen with minimum spf 30 atleast half an hour before going out in the sun. You can take non-sedating antihistamines such as Cetirizine or Loratadine(Claritin) when the rash appears. Short courses of oral cortisone or steroids are taken for short periods (one to three days) to settle more severe symptoms. You may take Vitamin C along with the prescribed treatment. Vitamin C is a general anti-allergy supplement. Also apply calamine lotion and a mild steroid cream like dermacort on the rash.
To prevent solar urticaria in future, desensitization using phototherapy and photochemotherapy are often advised. In this we try to decrease the amount of exposure by gradually increasing exposure to the form of radiation that brings about the reaction.
Please discuss this treatment option with your dermatologist.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.