30 year old female cousin with long history of neck pain admitted to hospital yesterday with high fever and toe pain/swelling. possible r.a. or lupus?

Fever: An inflammatory arthritis is a possibility as well as gout from your description. More concerning is the fever with the swollen toe. This is concerning for infection especially if an underlying disease such as diabetes. Hopefully you will have more answers and your cousin is feeling better in next couple days.

Could be infected: Neck pain may or may not be related, but the high fever, pain and swelling in the toe could be the signs of severe infection.