Tiny Blisters on Arch of Foot

Whenever I go on vacation and spend time in the sun and/or on a beach I get an odd rash on my feet.  It starts out as little bumps that I can feel under my skin that itch pretty bad.  They eventually turn into small blisters that ultimately grow to fairly sizable blisters.  I seem to only ever get them on the arch of my right foot and under my toes on my left foot.  I don't know if they are from exposure to sun (although I generally hang out in the shade), some form of heat rash, reaction to sand (from walking on the beach) or an allegeric reaction to sun screen (although why only my feet).  On this last vacation I took benadryl which eliminated the itch entirely but nonetheless the progression from tiny bumps to large blisters ensued.  I ended up popping the largest blister to drain the clear white puss from all the blisters so I could actually walk comfortably.

Is this some form of Eczema as I've read on other sites or what?  Any ideas on how to prevent it?

[Bhupinder Kaur, MD]

Hello,
These can be due to photodermatitis, foot blisters or fibromas. When a foot is hot and sweaty, the sock sticks to the foot. The sock and foot then rub against each other and the inside of the shoe causing blisters to appear. Plantar fibromas are firm, nodular masses which occur as a single mass or in clusters on the arches of the foot.

Wear shoes that fit properly and keep feet as dry as possible. Wearing wet shoes, boots and socks will increase your chance of developing blisters. So change socks regularly.
And use foot powder to help keep your feet dry. If the blisters still persist then please get it evaluated from a dermatologist/podiatrist.

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.