Is it safe to use one TNF inhibitor (e.g., infliximab) in a patient who has had a severe allergic reaction to a different TNF inhibitor (e.g., adalimumab)?  

The short answer is yes - it is ok to proceed with a different TNFi. First, it is important to determine whether the reaction was truly allergic or a nonspecific infusion reaction instead. If possible, obtaining a serum tryptase level at the time of the reaction can help clarify. Realistically, thi...