Can something give you a rash on only part of your body?

Thursday I found I was allergic to the sun tan lotion that I put on. Nothing too serious, I found another brand and all is well.

But it made me wonder: Could get a rash from it on my arms, but not on, let us say, my legs?

And I don’t mean specifically sun tan lotion. I mean, does it sometimes happen that part of the body will get a rash from something, but another part would not react?

Well, when my seasonal allergies really kick up, I get hives on my elbows, knees, ankles and wrists only - no other part of my body.

Yes, because not all skin is the same thickness. For example, the urushiel (sp?) oil that causes poison ivy rashes generally can’t penetrate the thick skin on the palms of your hands and soles of your feet, which is why it’s very rare to get poison ivy on those areas.

As for joints, I have no idea why but they seem to be more susceptible to rashes. Eczema, for example, typically shows up at joints like the elbows, knees, etc…

I had a massive allergic reaction to penicillin many years ago and broke out in huge, horrible hives, but only on my legs.

Similarly when I had what I think was a reaction to a different antibiotic the rash was most noticeable on my neck and upper chest.

yes, skin, or more correctly the underlying tissues and glands are very different in various parts of the body. Some things will affect one area and not another.

When I get an allergic reaction to an antibiotic, I get hives wherever I get warmest/sweat first. So, armpits and bra line usually get hives first.

Then, there are the critters that can cause “rashes” = chiggers and scabies come to mind. And, my boss has Lymes disease - the bulls-eye rash has popped up a couple of different places.

Just below my neck, above the breastbone, the skin often gets red and itchy there, usually when the weather heats up.

Also, I once got a rash on my abdomen from a hospital gown because of the detergent they use. Rash went away as soon as I put my own gown on.