eww.. help if you can bare to look.. is this an allergy rash or eczema?

[Kalie K]

I'm 16, I went to a school dance in a leather jacket. it never bothered me before, but it rubbed my skin a lot around my neck and back from all that dancing. It was irritating me when I got home, and then I woke up with a red, itchy, and slightly bumpy rash on my neck.. and a little on my back. I am not sure if I suddenly developed an allergy to leather, or if I developed eczema.. my brother has many allergies and eczema, but I have never had an allergy or rash or eczema before. it got slightly worse within the last 2 days... Could this eczema/allergic reaction rash seriously just pop up overnight? How long will it be there, and how do I cure it? I've been putting lotion on it (most natural moisturizing natural lotion I have), but I'm not sure if it is helping.

here's a picture of my neck..- http://i10.photobucket.com/albums/a147/super_kitty_scream/P2240453.jpg
please help? I feel like it might get worse.. any way to stop it?