Rash on left upper thigh and buttocks

I have a rash on my left upper thigh and buttocks.  I though it was poison ivey because when it first started i had smalls bumps on my arms and near my armpits.  I have been applying caladryl on the bumps and on the rash and been taking benadryl at night.  The bumps on my arm and near my underarms went away.  It looked like the rash was slowly going away but all of a sudden its back.  It gets really red and hot.  It feels like a welt.  What could it be?

[Bhupinder Kaur, MD]

Hello,
It is very difficult confirming a diagnosis without examination but it can be contact dermatitis, hives or bullous staph infection. Hives (medically known as urticaria) are red, itchy, raised areas of skin that appear in varying shapes and sizes. They have a tendency to change size rapidly and to move around, disappearing in one place and reappearing in other places, often in a matter of hours. The most likely triggers for acute urticaria are allergies to pets, horses, latex and foods, such as shellfish and nuts,bee or wasp stings, allergies to medicines, Viral infections, such as glandular fever and herpes, dental and sinus infections, fungal infections, blood transfusions and vaccines.

Take some antihistaminics like Benadryl and apply the steroid cream. You can also apply calamine lotion as it helps in soothing the skin. If the symptoms persist then topical and oral steroids may be needed. I hope it helps. Take care and regards.