I know someone who has eosinophilic esophagitis. In his case, it's being treated as an autoimmune disease, as opposed to a chronic allergic condition. Never heard of it in relation to AS or NSAIDs.
perhaps found something here: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1002150/pdf/annrheumd00284-0051.pdf
diagnosed with AS April 2018, starting with cervical pain/stiffness; Aug 2018 enthesitis/bursitis left Achilles
diagnosed with iridociclitis Nov 2017 (4 flares so far) - bilterally DES,PVD
Signs of inflammations/erosions on MRI`s for axial and Achilles/calcaneus + bursitis
Sulfasalazine 3g 08.2018-05.2019
currently COX2 inhibitor 90mg
Supplements: vit A/C/D, reishi mushrooms, fish oil/probiotic/ Mediterranean NSD