small blister on index finger...recurring?

I have been on Accutane for 3-4 months now.  I have had the accompanying symptoms of dry skin, chapped lips, and dehydration.  A month ago while baking a cake, I noticed a small pain on my middle finger near my knuckle and saw a blister the size of a pinhead.  I assumed my now-sensitive skin had reacted to the heat of the oven.  It healed and went away.

Yesterday, I noticed the same blister.  I even popped it to make sure it was a blister, not a wart or growth of some kind.  I kept poking at it and I think I irritated it.  It hurt to press on.  

I have gotten cold sores before and am afraid that this is a case of Herpetic Whitlow.  In your medical opinion, do you think it is just a case of dry skin or HSV?

Thanks.

[curiouser777]

Note: I was outside in the freezing cold for some time before noticing the 2nd blister.

[Bhupinder Kaur, MD]

Hello,
It can be herpetic whitlow or blisters due to pompholyx or dyshidrotic eczema. Herpetic whitlow is a painful viral infection occurring on the fingers or around the fingernails and is caused by infection with the herpes simplex virus (HSV). Eczema is a form of chronic dermatitis (rash).Allergic reaction is one of the important causes of eczema.

My sincere advice would be to get it evaluated from a dermatologist to confirm the diagnosis. 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 dermatologist. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.

[curiouser777]

Thank you for your response.

I called my derm a few days ago (mostly to inquire the face tingling I had been getting as of late), and she told me to stop Accutane until the little blister heals.  Then, to restart the course and see if the tingling goes away during my hiatus from isotretinoin.

The blister is gone, other than a raised red scar which is about 2 mm wide.  My cold sores took two weeks to heal.  Perhaps, this took a shorter while due to its size?  I did have slight rashes on both my hands at the time I noticed the blister, and had neglected  to apply and reapply lotion onto my hands.  When I discovered the blister the second time, it didn't hurt.  It was just there and wouldn't pop.  It hurt after I had been (unwisely) poking at it for an hour.  

Then I opened the blister with a tweezer.

I hope it's not herpetic whitlow!

[curiouser777]

For those who are suffering something similar, my derm took a second look at it and determined the blister was actually a result of eczema. The remaining bump is apparently scar tissue, not a wart.