Is it possible that elevated histamine load in CSU might increase the frequency of dysmenorrhea and prolong histamine clearance rate


Background: HURDLE is a prospective, cross-sectional multicenter study. The first step of the HURDLE project is regional (HURDLE-I) and will only recruit patients from Turkish UCARE centers. The second step (HURDLE-II) will be international.

Histamine is the key mediator that leads to the de­velopment of itch and wheals in CSU. Imbalances in the control of histamine levels due to inefficient histamine clearance may lead to histamine accu­mulation and to the development of undesired hista­mine-related manifestations such as urticaria, accelerated gastrointestinal transit, or dysmenorrhea. It is still not clear whether some CSU patients might suffer systemic symptoms other than skin manifestations and also it is not clear whether histamine catabolism in CSU patients is altered or not.

The primary aim of this study is to investigate the frequency of dysmenorrhea in women of reproductive age diagnosed with CSU and change in dysmenorrhea severity after the diagnosis. Additionally, the histamine clearance rates (measured with histamine-50-prick-test) of the same patient group will be compared with the general population.


Project lead: Murat Türk

Supervisor: Emek Kocatürk

Steering committee: Ümit Murat Şahiner, Emek Kocatürk, Ragıp Ertaş, İnsu Yılmaz, Marcus Maurer



Ethical board approval: The study is approved by the Erciyes University Ethical Board (date: 08.11.2023, no: 739)


Status: HURDLE-I has started at 12/2023 and planned deadline to recruit patient information is 04/2024.


Autorship criteria: UCAREs get to nominate one coauthor per 10 patient and control data.



After gaining results from HURLDE-I, detailed information about global rollout of HURLDE-II will be announced soon.


Detailed information: Murat Türk,

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