These preparations are available by prescription only but can be life saving and should be carried by all patients with a history of systemic responses to these insects. It is especially important to carry one of these preparations if one is going to be participating in activities in remote areas. Antihistamines can be helpful but are not adequate for a life-threatening situation. Some hikers have found that applying Adolph's Meat Tenderizer, a preparation that contains the enzyme papain, can make their stings less painful. Immunotherapy or allergy shots for cats generally work.
Work is in progress on oral and inhaled immunotherapy.
It is likely that some new treatments currently under investigation will be effective. Some doctors believe that weekly bathing of the cat reduces exposure to allergens enough to decrease symptoms. There are products available from allergy supply houses that help to break down cat allergen that may be trapped in carpeting or furniture. I thought this was bizarre but read that people sometimes have allergic reactions to stress on joints. However, hives following exercise, or exercise induced urticaria is a well-known condition.