Hi,
Welcome to the ehealthforum and I am glad to help you out. From the symptoms it looks like sebaceous cysts. The other possibility for this bubble can be shingles sores if the sore becomes painful and a cluster of bubbles appear.
What exactly is this can be diagnosed only after examination of the area. Till that time you can apply warm compresses and some topical antibiotics like Neosporin.
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.