Polycythaemia rubra vera and water-induced pruritus: blood histamine levels and cutaneous fibrinolytic activity before and after water challenge

Abstract

We studied blood histamine activity (HA) and cutaneous fibrinolytic activity (CFA) in a patient with polycythaemia rubra vera (PRV) and water-induced pruritus, before and after water exposure. The results suggest that the water-induced itching in PRV is associated with an increase in HA. In addition, markedly increased levels of CFA were found both before and after water exposure. These findings have been previously reported in patients with aquagenic pruritus (AP) but not in patients with PRV. As the water-induced itching in PRV and AP share many common features, these findings suggest that the pathophysiology of the water-induced pruritus in these two conditions may be similar.

Pivotal role of mast cells in pruritogenesis in patients with myeloproliferative disorders

“…1 Gilbert et al 37 and Steinman et al 38 have shown increased levels of histamine in the blood and urine of patients with MPDs; and the incidence of pruritus was shown to be significantly higher in patients with elevated histamine levels compared with those who had normal histamine levels. However, there were also studies that did not confirm a correlation between PV-associated pruritus and levels of blood histamine.…”

The JAK2V617 mutation induces constitutive activation and agonist hypersensitivity in basophils from patients with polycythemia vera

“…32 This symptom can antedate diagnosis or appear during the course of the disease; it is poorly responsive to phlebotomy or myelosuppressive therapy, while interferon-α, 33.34 or selective serotonin reuptake inhibitors 35 can be successful. Pruritus has been associated with iron deficiency, 36 high leukocyte count, 36 platelet activation, 35 histamine release, 37,38 infiltration of the derma by mononuclear cells and eosinophils, 39 and degranulation of dermal mast cells, 39,40 but the underlying mechanisms remain substantially obscure. Furthermore, we, like others, found that pruritus was more common among patients harboring a greater than 50% V617F allele burden; 26,27,41 accordingly, we found that the number of circulating activated basophils, measured by their expression of CD63, was significantly increased in this category of patients.…”

Water-Induced Itching

“…Finally as in AP, in 1 patient each with PRV. increased serum histamine and elevated CFA [27] and activation of acetylcholinesterase [12] have been reported. In the latter case, topical scopolamine and NaHCOj added to the water did not influence the symp toms.…”

“…Therapy of PR V often improves the pruritus, but up to 20% of the patients continue to have symptoms [26]. Medicamentous treatment of low iron levels and elevated scrum histamine [23,27] have been tried but with uncon vincing results. In 4 cases, iron substitution improved pru ritus considerably [28], but in others it was ineffective [25] and moreover it was limited by an unacceptable increase in hemoglobin levels.…”