Aquagenic pruritus: associated diseases and clinical pruritus characteristics.

BACKGROUND: Aquagenic pruritus (AP) can be induced by systemic diseases. The distribution of underlying diseases in a representative patient collective has not been investigated. This retrospective study aimed to determine the frequency and pruritus-specific parameter of systemic diseases in a series of patients.

PATIENTS AND METHODS: Data of 39 patients with AP (24 f, 15 m; mean age: f: 51.3 ± 20.1, m: 57.2 ± 15.0 years) were obtained and statistically evaluated as follows: demographic data, pruritus characteristics, underlying diseases, family history.

RESULTS: 30.8 % of patients exhibited polycythemia vera or myelofibrosis (Group 1: G1), in 69.2 % (G2) no underlying disease was found. 25.6 % had lactose intolerance as possible contributing factor. Women were significantly more common in G2 (p < 0.01), with a lower mean age (p < 0.01) and longer duration of AP (18.9 years, p < 0.01).

CONCLUSIONS: AP occurs frequently with polycythemia vera. Other underlying diseases are rare; in over half of the patients no cause can be detected. In 25 % lactose intolerance is present which possibly acts as co-factor. Demographic parameters (age, gender) allow estimation of the possible underlying disease in AP. Pruritus characteristics are similar in all groups and not helpful in determining the origin of AP.