I have never made a plaster like yours, but as a dressing, I often use raw Sichuan aconite root. My master once taught me that no matter what medicine is used for external application, it must be mixed with boiling water, so as to avoid irritating the skin. In fact, in other words, the crude drugs are boiled at the temperature of boiling water. Of course, this is only one of the wonderful uses. There are many benefits in mixing medicines with boiling water, so I won't cite one example.

However, as a plaster, it can also be regarded as a kind of dressing. I think you should sprinkle the powder of Radix Aconiti Kusnezoffii when the fixative is very hot, so that this allergic reaction can be generally avoided.

However, some patients have sensitive skin, which requires careful observation and inquiry during use. Once the skin is found to be itchy and rash, stop taking medicine and take measures.

As for what measures to use, I used the method of allergic reaction after Professor Zheng Huaixian used the new wound medicine, that is, external rubbing with Fu Relaxing Borneol Ointment, which had a good effect. You can also apply a layer on the part where patients with sensitive skin need to apply medicine or paste medicine, and then use external medicine, so the probability of allergies is much smaller.

Personal experience is for reference only.