Chronic pruritus is difficult to treat and requires the evaluation of new therapeutic modalities. We initiated an open-labelled, two-arm prospective, proof-of-concept study applying two selective serotonin re-uptake inhibitors on a long-term basis. Paroxetine and fluvoxamine were tested in a total of 72 pruritic patients (27 men, 45 women, age range 28-88 years, mean age 59.2 years). The reduction in pruritus was evaluated by analysis of visual analogue scores and determination of the maximal antipruritic effect (maximal percentual reduction in pruritus). Forty-nine of 72 patients (68.0%) experienced a weak (n=9), good (n=16) or very good (n=24) antipruritic effect. Statistical analysis proved the efficacy of paroxetine and fluvoxamine with no significant difference. The best response was observed in patients with pruritus due to atopic dermatitis, systemic lymphoma and solid carcinoma. Chronic scratch lesions healed completely in 14/31 patients and partially in 17/31 patients. Adverse drug effects were observed in 70.8% of patients, resulting in discontinuation of treatment in 18 patients. These results support previous reports of high antipruritic potency of selective serotonin re-uptake inhibitors, which are a good alternative treatment modality in chronic pruritus. This should be confirmed in future double-blind studies.

Chronic pruritus is a symptom of many diseases, with studies pending investigating its prevalence or incidence. The aim of this study was to describe the characteristics of the underlying diseases in a large number of patients. A total of 263 patients (110 men, 153 women; age range 8-95 years; mean 55.9 years) were included in the study. The following data were collected from patients presenting over a 3-year period: gender, age, history, skin lesions, laboratory, histological and radiological investigations. An underlying dermatosis was identified in 41.8% of patients, a systemic disease including unidentified neoplasms in 13.3% and a neurological disorder in 0.4%. No disease was found in 44.5% of patients. Among the patients in whom no disease was found, 55.6% of the, mainly elderly, patients had an accumulation of many co-factors, suggesting an own subgroup with multifactorial origin for the pruritus. The distribution and type of secondary scratch lesions gave no clue as to the underlying disease. In conclusion, patients with chronic pruritus present a inhomgeneous collective with different underlying diseases, including malignancy, necessitating thorough investigation.