Thank you for reaching out to us.
We are sorry to hear of your possible reaction to chlorine at the mikveh.
The suggestions that you received–asking about local mikveh chlorine levels and arranging to immerse before the water is treated–are good ones. We recommend contacting mikva’ot in your area to explore these possibilities. Mikveh waters are regularly tested for chlorine levels, and it is often the attendant who adds the chlorine at the beginning of a shift.
We’d also add a third question: clarifying whether the local mikva’ot use chlorine or a different agent, since your reaction may be specific to chlorine.
Additionally, in this situation, we’d recommend dipping only once in the mikveh, in order to reduce your head’s exposure to the water. You may also shower at the mikveh immediately after dipping, washing your head and your body separately (see more here). Seasonally, depending on where you live, you may also have the option of immersing in a natural body of water.
You also might find it helpful to consult your physician about other potential steps that could mitigate these flare ups.
We hope this helps. Please let us know if we can be of further assistance.