My understanding is that exposure therapy is nowadays the recommended way to deal with milder allergies. My daughter was allergic to eggs and the doctors advice

My understanding is that exposure therapy is nowadays the recommended way to deal with milder allergies. My daughter was allergic to eggs and the doctors advice was to start to slowly introduce them to her diet. About half a year after starting this, she could eat eggs in food no problem. I've also personally cured my cat allergy. We adopted a cat that was supposedly of hypoallergic breed ("supposedly" because there's really no science behind it, it's just people reporting less reactions from this breed). I still got a mild allergic reaction to her initially, but after a few months, it stopped. Now, a few years later, we are still happily living with her and it seems that I've ceased being allergic to other cats also.