Hi! Thank for posting your concern on HCM. I will need more information to answer your question. Do you have fever, and how is your general condition? Does the lesions itch? Are the blisters yellow? It may be an allergy if they are itchy, but in general allergy does not give blisters. Can be also many other options, depending on the answers of the questions below, and on the look of it. If its not getting, better, but worse, I would recommend you follow it with a dermatologist, who according the case may refer you to a infectious disease specialist. Hope this helps, Take care Dr. Klarida