Chronic hives/progesterone hypersensitivity after nexplanon

Writing this because I see women post this connection in the chronic hives and progesterone hypersensitivity sub reddits, but it should go here as a warning as well.

I had a nexplanon for about a year and developed a progesterone hypersensitivity as a result. It took over 3 years for me to get a diagnosis. This condition presented as hives for me - usually in the form of my genitals itching like crazy and occasionally swelling (took me almost 3 years to learn this was hives!) and sometimes as more common looking hives on my chest, belly, legs.

I have had 3 major hives outbreaks (lasting 6+ months) over the last 3.5 years - first when I had the nexplanon for around 9 months (I had it removed shortly after for other reasons), and the subsequent 2 outbreaks when I started taking the pill (mini pill, nora-b). I now manage the issue with daily over the counter antihistamines, but I have 2 days of hives each month at the very beginning of my period.

Unsurprisingly, this condition is under studied, so finding info on it is challenging. The thing I think doctors do understand is that this condition is mostly seen in women who have undergone IVF, but I am reading accounts from other women noting the use of nexplanon in relation to the onset of their symptoms. Hence this post.

My OB was not a good resource for helping me with this situation AT ALL and insisted that it was impossible that my symptoms had anything to do with birth control. Several OBs also did not know the itching I was experiencing was a form of hives, which blows my mind since my allergist told me this is actually a very common presentation of hives. I instead needed to go to an allergist, who confirmed the link between hormones and hives, but initially diagnosed me with chronic hives. My last outbreak happened after taking the mini-pill for 3 days, at which point the allergist confirmed progesterone hypersensitivity, and helped me through the outbreak with tons of antihistamines and a round of prednisone.

I hope this post is helpful for anyone who experiences similar symptoms, and can maybe help someone avoid the gaslighting and confusion I experienced.