Treatment of pruritus associated with systemic disorders in the elderly: a review of the role of new therapies.

Generalised pruritus is common in the elderly. Idiopathic 'senile pruritus' is a diagnosis of exclusion, and an underlying systemic disorder should be sought. Thyroid disease, haematological malignancy, iron deficiency, cholestasis or renal impairment may be responsible for pruritus. Rarely pruritus may occur after cerebral infarction or as a paraneoplastic phenomenon. The mechanisms of pruritus are poorly understood. In systemic disorders, correction of the underlying disorder alleviates itch. However, when this cannot be achieved, a symptomatic approach is required. Response to treatment varies enormously and an empirical approach is often required. Topical applications are available to soothe the skin and bandaging techniques may improve their efficacy. A number of more targeted treatments are available for renal and cholestatic pruritus. Novel therapies such as thalidomide, opioid antagonists, ondansetron and phototherapy with ultraviolet (UV)-B radiation are now being used. Treatment of pruritus needs to be individualised, and the elderly present a particular challenge. Adequate delivery of simple emollients may be impossible because of physical impairment The elderly are more vulnerable to the adverse effects of treatments, comorbidities may alter the pharmacokinetics of drug metabolism and polypharmacy increases the likelihood of adverse drug interactions. Cognitive impairment can lead to poor compliance with treatment. The patient's general health, the severity of symptoms and the adverse effects of treatment all need to be considered. Most treatments are of benefit only to some patients; others derive only marginal improvement. Many of the newer treatments are unlicensed for pruritus and should preferably be administered under specialist supervision. We review the literature concerning the treatment of itch associated with systemic diseases, with particular emphasis on issues relevant to the elderly. Pruritus is a difficult symptom to treat. However, it is hoped that research into the mechanisms underlying the pruritus of systemic disease will allow a better understanding so that we should be able to look forward to more specific and effective therapies in the future.