Predictors of malignancy development in patients with chronic pruritus

• Pruritus is associated with an increase incidence of certain malignancies.
• In patients with chronic pruritus, age ≥ 60, male sex, and current or prior smoking increase the odds of malignancy development.
• Improved understanding of those patients most at risk for cancer development target screening practices.

BackgroundPatients with pruritus have been shown to have an increased incidence of certain subtypes of malignancy.ObjectiveTo assess predictors of malignancy in patients with chronic pruritus without prior dermatologic diagnoses.MethodsCase-control study of 398 patients with chronic pruritus who developed a malignancy were compared with 8346 patients with chronic pruritus who did not develop a malignancy. Primary outcomes were odds of developing incident malignancy.ResultsAge greater than 60 years (OR 4.04, 95% CI 3.08, 5.31), male sex (OR 1.39, 95% CI 1.13, 1.71) and liver disease (OR 2.37, 95% CI 1.00, 5.65) were predictors of malignancy development in patients with chronic pruritus and non-diseased skin. In an exploratory analysis with multiple imputation via chained equations, age greater than 60 years (OR 4.13, 95% CI 3.15, 5.42), male sex (OR 1.26, 95% CI 1.02, 1.55), and current or prior smoking (OR 2.02, 95% CI 1.42, 2.88) were predictors of malignancy development in patients with chronic pruritus and non-diseased skin.LimitationsPotential for misclassification and detection biases. Missing data.Conclusions and relevanceIn patients with chronic pruritus without concomitant dermatologic diagnoses, older age, male sex, liver disease and tobacco abuse increase the odds of an underlying malignancy.