Pruritus aquagener L29.8

Unknown; a "water-induced" activation of mast cells is postulated. The symptom is often described as a concomitant or premonitory symptom in myeloproliferative systemic diseases (Zeidler C et al. 2020).

The most common association is with polycythemia vera, which is reported to be 40-50%. In these cases, a mutation in the enzyme Janus kinase 2(JAK2) is highly associated. The mutation leads to an increase in CD63+ eosinophil and basophil granulocytes, which are constitutively activated and induce the degranulation of mast cells in the skin. A premonitory occurrence of aquagenic pruritus (on average 6.6-8.6 years) before the diagnosis of polycythemia was observed in the majority of patients (Zeidler C et al. 2020).

In addition to haematological diseases, intestinal diseases such as lactose intolerance, side effects of medications such as chloroquine or hydroxychloroquine and hepatitis C may also be the cause (Zeidler C et al. 2020).

Familial clusters have been observed in isolated cases (Heitkemper T et al. 2010).

Severe symptoms, sometimes described as burning or pungent itching without visible skin changes, occurring regularly after contact with water, regardless of the temperature of the water. Myeloproliferative diseases can be detected in about 30% of patients. In addition, a lactose intolerance is often found. Other associated diseases are: essential thrombocythemia, hemochromatosis, infectious diseases such as hepatits C; neoplasia such as uterus carcinoma, acute lymphatic leukemia, T-cell lymphomas, hypereosinophilic syndrome, drugs (antimalarials, bupropion).

• It is possible to try to develop tolerances by regular, increasing contact times with water.
• The best results are achieved by a PUVA bath therapy. Alternatively: UVB irradiation, also 311 nm narrow spectrum UV therapy.
• Local application of a 5% polidocanol cream(1-2 times/day) or capsaicin 0.01-1% as cream, shaking mixture or gel.

Around 30% of patients respond positively to non-sedating antihistamines such as desloratadine (Aerius) 1-2x2 tbl.l/day p.o. or levocetirizine (Xusal) 1-2x2 tbl.l/day p.o. Good and resilient positive effects can be achieved with UV therapy (UVB and PUVA). Other treatment options are anticonvulsants (e.g. pregabalin, naltrexone, paroxetine).

The best effects can be achieved after failure of antihistamine therapy with ^Pregabalin® 50-100 mg).

For aquadynia, ibuprofen is recommended 30 minutes before water contact.

In case reports of patients with polycythemia vera, the use of ruxolitinib (Janus kinase inhibitor) has recently proven to be a potent agent against the underlying disease and against itching.

Aquagenic pruritus > 30 min. mainly on the trunk as well as with the use of skin care (creams) indicates a neoproliferative neoplasia.

1. Cao T et al. (2015) Idiopathic aquagenic pruritus: pathogenesis and effective treatment with atenolol. Dermatol Ther 28:118-121
2. Goodkin R et al (2002) Repeated PUVA treatment of aquagenic pruritus. Clin Exp Dermatol 27: 164-165
3. Heitkämper T et al (2010) Aquagenic pruritus: Associated underlying diseases and clinical pruritus characteristics. JDDG 10: 797-805
4. Holme SA et al (2001) Aquagenic pruritus responding to intermittent photochemotherapy. Clin Exp Dermatol 26: 40-41
5. Lubach D (1984) Aquagenic pruritus sine materia. Dermatologist 34: 600-601
6. McGrath JA et al (1990) Aquagenic pruritus and the myelodysplastic syndrome. Br J Dermatol 123: 414-415
7. Newron JA et al. (1990) Aquagenic pruritus associated with the idiopathic hypereosinophilic syndrome. Br J Dermatol 122: 103-106
8. Nosbaum A et al. (2011) Treatment with propranolol of 6 patients with idiopathic aquagenic pruritus. J Allergy Clin Immunol 128:1113
9. Shelley W (1970) Post-wetness (aquagenic) pruritus. JAMA 212: 1385
10. Siegel FP et al. (2013) Aquagenic pruritus in polycythemia vera: characteristics and influence on quality of life in 441 patients. Am J Hematol 88:665-669
11. Treudler R et al. (2002) Familial aquagenic urticaria associated with familial lactose intolerance. J Am Acad Dermatol 47:611-613
12. Zeidler C et al. (2020) Clinical shortcuts in the differential diagnosis of pruritus. Dermatologist 71: 493-499