I have a strange "allergic reaction", and I'm kind of freaked out...? I was recently playing softball on my school's foeld (which was just sprayed with weed killer and had new dirt spread on it), and when I got home I noticed a strange leopard-like, red rash-thing going up my arm.  I took a shower and some Benadryl, and felt better.  This morning it was no longer noticeable and wasn't itchy, so I went to school.  However, after a fire drill (in which we went outside on a hill near the school, nowhere near the softball field) I noticed the rash again, now also on my hands.  I called my mom to come pick me up, and I am now sitting in her office at work, feeling fine after more Benadryl.  I am, however, still wondering what is happening to me.  Am I allergic to the weed killer, or a bug bite I got or something?  Or is it more serious?  If you have ever experienced or heard of this, please answer.  Thanks!

Summarized question: Does weed killer make you allergic?