Hello, Thanks for Writing to Health Care Magic and putting trust in us regarding your Health related query. I am Dr. Saleha and I have read your message in detail, I understand your concern and will try to help you in this. I am sorry for what happened after the bleaching but it s comforting to know that it settled down well. Here we have two points to notice. +It happened twice in last 10 times. +It got settled by measure which are taken for allergic reactions (benedryl and cold compress). This leads me to make opinion that you are having allergic reaction to the bleach. Now if you were allergic to all types of bleach you wouldn t have got it just twice, it means that there is a particular brand which probably contains some ingredient which causes allergy to your scalp. The cure to it is actually simple, +First am foremost is avoiding that brand, just go to your hair expert and ask about the bleach brand used that day, then start avoiding it, always tell your hair expert that you are allergic to that particular brand , avoiding the allergy causing substance is always the best defence against allergy. +second thing is treatment if you somehow feel that you are getting allergy after a bleach immediately take anti-histamin and try to get your scalp cleaned off that cosmetic. When ever you go for hair treatment keep antihistamin like benedryl with you, just in case you need it. You don t have to panic about this matter all you need is a bit of care ,everything will be fine . I hope this answers your question.If you have more questions, I am happy to answer. Wish you lasting health. Regards. Dr.Saleha Saeed.