Skin rash after castor oil pack

Anyone... I've been using a castor oil pack for the last two nights to try to alleviate back pain. Today I woke up with a rash on my wrist which has now advanced all the way up my arm (inside). Does the castor oil pack help to expel toxins and could that be what's causing the rash? I haven't had any other symptoms and I still have back pain.

Deva Tweet