Painful reocurring blisters on finger

From the time my son was 4 months old, every time he gets sick with a cold or virus he developes these blisters on his thumb.  It becomes red and swollen, has fever in it, and then the blisters appear.  His thumb will eventually become almost twice as big as it should be and is extremely painful for him.  After the blisters finally pop, he has holes in his thumb where the blisters were.  When my son is not sick or suffering from this, you can still see the spots on his thumb where the blisters appear.  They are the same color as his skin, but just ever so slightly raised from his skin.  I have consulted his doctor about this, as I take him every time he has an outbreak.  He thinks I'm crazy that this is related to him being sick.  He gives me an antibiotic and muprocin creme.  I just really don't know what to do or think.  It has been about a year since his last outbreak.  Last week, he was diagnosed with bronchitis and this week he has blisters on his thumb.  Please help!!!

[Bhupinder Kaur, MD]

Hello,
These recurring blisters can be due to hands, foot and mouth disease, pompholyx or dyshidrotic eczema or fever blisters due to herpes simplex 1 infection.

In hands, foot and mouth disease, a blister-like rash on the hands, feet and in the mouth usually develops one to two days after initial symptoms of fever and sore throat. Pompholyx is characterized by a sudden onset of many deep-seated pruritic, clear vesicles which itch and then peel off. As a result the skin may also fissure.

I suggest you to get it examined from a 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.