I had asked for some further information and have not heard back.
If the reaction to the bites occurs more quickly and is usually associated with a low grade fever, then it is more likely to be an allergy. If the reaction is more delayed, particularly by at least a couple days, and is associated with a higher fever, then it is more likely that there is an infection causing the reaction.
Of course, these problems are not mutually exclusive, in that there can be an initial allergic reaction that subsequently gets secondarily infected. And the infection may only occur at some times but not others. Apparently, he definitely had a Staph infection recently for which he is taking antibiotics.
If there is an allergic reaction, then the usual initial approach would be the use of antihistamines, which is likely what has already been tried. If traditional antihistamines are not sufficient, then a variant of antihistamines that are used for acid irritation syndromes, such as ranitidine, may be used to augment the traditional antihistamines. Additional interventions would require prescription medicines, so it would be necessary for him to see his doctor. If there are more significant allergic reactions that are difficult to control, it also may be reasonable to consider seeing an Allergist for testing and desensitization treatment.
If the problem is that these are getting frequently infected, then it may be necessary to use interventions to prevent infections, both by regular cleaning with soap and water, disinfection with alcohol or witch hazel, and protection with bandages (to keep him from scratching and picking at bug bites).
Another option would be interventions to prevent the bug bites, including using greater coverage with clothing and insect repellents, such as Deet.
If I can provide any clarification, please let me know.