Clinical characteristics differ considerably between phenotypes of bladder pain syndrome/interstitial cystitis.

Objective: Bladder pain syndrome/interstitial cystitis (BPS/IC) is one of the most bothersome conditions in urological practice. This syndrome includes a heterogeneous collection of underlying pathological conditions. Compared to the classic IC with a Hunner lesion, now denominated European Society for the Study of Interstitial Cystitis (ESSIC) type 3C, the non-Hunner type of BPS/IC appears different concerning demographic, endoscopic and histological findings, as well as the response to all forms of treatment. The objective of this study was to determine whether there are additional dissimilarities in clinical presentation between the main phenotypes of BPS/IC.

Material and methods: In total, 393 BPS/IC patients (210 type 3C and 183 non-Hunner), diagnosed according to National Institute of Diabetes and Digestive and Kidney Diseases and ESSIC criteria, were studied by surveying the clinical records including micturition diaries.

Results: In this clinical material, BPS/IC ESSIC type 3C accounted for 55% of cases. Patients with non-Hunner disease were on average 20 years younger at the time of diagnosis. Furthermore, there was a marked and significant difference in bladder capacity under general anaesthesia (p < 0.0001).

Conclusions: The findings in the present series, together with previously published reports by this group and by others, confirm the striking differences between the main forms of BPS/IC and underline the indispensability of adequate subtyping in clinical studies.