Antibiotic Allergy

My son (17) last year was given minocycline 100mg daily for the treatment of acne. He quickly came to the hives all around his face and neck, which I think can be very dangerous. I went back to the GP and explained. My son also had a bad reaction to erythroped like a baby.
Should I be concerned about this and if so, why my son GP not advise him to others on which antibiotics should be avoided? My fear is that now he is an adult, if he became ill and was unconscious and unable to tell about his previous responses to these drugs.
Do you think a GP would be held a consultation on this subject as a waste of time?
I am also curious what you think of tattoos and if medical emergency medical personnel do not think looking for one?
Thank you in advance,
Jane

I havnt heard of anyone with a tattoo before but medical necklaces and bracelets are available to alert the purchase of medical personnel who will look.
Your doctor must have put these allergies your son notes for future reference and medical personnel be informed.