Interstitial cystitis, bladder pain syndrome, hypersensitive bladder, and interstitial cystitis/bladder pain syndrome – clarification of definitions and relationships

Interstitial cystitis and interstitial cystitis-related conditions such as bladder pain syndrome and hypersensitive bladder have a similar symptomatic profile but probably different etiologies. A meaningful classification of these diseases/conditions is mandatory for clinical and investigational progress. The condition with Hunner lesions (Hunner type interstitial cystitis) is distinct from other categories in terms of histopathology, gene expression, and clinical management. Classification should clearly differentiate the presence or absence of Hunner lesions. The term covering patients as a whole should contain interstitial cystitis, since interstitial cystitis is historically a well-known name and used for insurance reimbursement. The proposed taxonomy features an umbrella term (interstitial cystitis/bladder pain syndrome) and two subgroups, Hunner type interstitial cystitis (with Hunner lesions) and bladder pain syndrome (without Hunner lesions). Interstitial cystitis/bladder pain syndrome is convenient for initial management, and subgroups can categorize the patients for specific management. The characteristic symptom profile is to be collectively termed as hypersensitive bladder symptoms.