Well, joint pains with rash can be seen in SLE, psoriatic arthritis, fibromyalgia, polymayalgia rheumatica and
chronic fatigue syndrome. Gout
, though typically affects the great toe, can cause multiple joint pain with rash. Hashimotos Thyroiditis is another possibility. Hayfever and rheumatoid arthritis too should also be ruled out. It looks like rheumatoid arthritis has been ruled out in your case.