How do you approach work up for underlying rheumatologic disease in patients referred for chronic urticaria?  

Chronic urticaria (6 weeks or longer) is often a self-limited disorder seemingly idiopathic in etiology. There are certain autoimmune disease more prevalent in patients with chronic urticaria including systemic lupus erythematosus, Sjogren's syndrome, autoimmune thyroid disease, celiac sprue, and rh...

I do the above but also get a TPO antibody. That is not recommended by A/I but more than 1 patient has had this positive and treating with levothyroxine has decreased urticaria.