Water-induced pruritus in haematologically controlled polycythaemia vera: response to phototherapy.

BACKGROUND: Water-induced pruritus is characterized by the development of intense and widespread itching after contact with water at any temperature and without observable skin lesions. Around 40-52% of patients with polycythaemia vera (PV) have water-induced pruritus, and more than 20% of the patients continue with symptoms despite an adequate control of the underlying disease. The aetiology is unknown and treatment is often unsuccessful. We report a patient with a haematologically controlled polycythaemia vera and water-induced pruritus that responded to phototherapy.

METHODS: An 83-year-old woman with haematologically controlled PV referred with intense water-induced pruritus without cutaneous lesions. Topical emollients and oral antihistamines were unsatisfactory and so phototherapy treatment (90% UVA/10% UVB) three times a week was commenced.

RESULTS: Improvement was visible after 1 month and at the end of 3 months the pruritus had disappeared and treatment was stopped.

CONCLUSION: It is considered that the successful treatment in this patient is due to the UVB radiation.