I'm not sure about testing you have had, if you already mentioned it remind me. If steroids are making you itch it could be that you are allergic to a class of steroids. There are 5 classes and I am only allergic to one. That is the class that cortisone cream is in, plus many other common steroids. It gets even more complicated if allergic to the class I tested positive to, there can be a cross over to two other classes of steroids so those should be avoided. Yet that does leave me with two other safe for me classes of steroids.
I am wondering if your scalp issue escalated because of an allergy to a steroid? It is rare. Yet we are in this group because we are the exceptions. The 1%. Once again doctors let me down for years on this issue. I had burning on my female privates and the gynecologists' prescribed steroids. It burned badly immediately after application. I told them that and was told I couldn't get better if I didn't keep using it. I could tolerate at most for 30 minutes of misery. A month later got the 5 Day Extended Patch Test and one positive was to the steroid in cortisone. I called the nurse and told me there was no such thing and to keep using the cream. I sent the office my test results and so in the future they would not assume cortisone is always safe. Never heard back and never went back to this large, big city doctors group.
No more issue now because of diet changes. No more processed sugar to fuel my yeast colonies. We all have living yeast in our systems, but starving them from their sugar kills them.
Why are you afraid of a topical anti-biotic? I am allergic to sulfa oral antibiotics, but not aware of any topical anti-biotic issues. My only concern would be the media it is in as I am allergic to preservatives. Get all the active and inactive ingredients and study on the internet for allergic reactions.