If you have a patient with EoE on Dupixent 300 mg weekly, and they have severe tree nut allergies, would it be safe to add Xolair for severe food allergy?

Yes, it would be safe to add Xolair if deemed absolutely necessary through shared decision making with the family. However, I generally do not recommend using more than one biologic medication at a time. Additionally, while Dupixent has not been approved for the treatment or mitigation of food allergies, there is some data to suggest that Dupixent may indirectly lead to a decrease in serum specific IgE levels so there is hope that Dupixent could potentially decrease the reactivity to foods. My approach in this scenario would likely be to check serum IgE levels to the tree nuts in the beginning of the Dupixent treatment and then re-check 4 to 6 months into treatment. I'd be looking for a decrease in the ssIgE levels as a way of offering some...