Aquagenic Pruritus Questionnaire: Predicting Myeloproliferative Neoplasms in Patients with Aquagenic Pruritus

Aquagenic pruritus (AP) is an underrecognized condition in which patients perceive itch following contact with water on clinically non-lesional skin. AP is frequent in patients suffering from myeloproliferative neoplasms (MPN) such as polycythemia vera and may manifest several years prior to MPN diagnosis. To date, there is no validated patient-reported outcome measure (PROM) assessing AP and its association with MPN.

In this multiphase study, eight questions relevant to AP were developed and validated in 77 patients with AP and 50 patients with chronic non-aquagenic pruritus (CP). After reduction to those questions relevant for distinguishing between AP with and without MPN, the resulting questionnaire was validated in 76 patients with AP (37 with MPN) and 76 with CP. The predictive power of the questionnaire's score was retrospectively tested in the first cohort.

Four key questions were identified as central to differentiating MPN in AP, forming the basis of the AP questionnaire (APQ). Sensitivity and specificity of the score reached 97.3% and 79.5%, respectively. The APQ classified five patients with AP with MPN who were diagnosed with MPN at a later stage.

APQ is the first validated PROM for patients with AP, detecting a potential relationship to MPN with high sensitivity. APQ is a useful addition to standard of care in patients suffering from AP, potentially shortening the delay of MPN diagnosis.

German Clinical Trials Registry, DRKS 00006075.