Predictors of malignancy development in patients with chronic pruritus

Patients with pruritus have been shown to have an increased incidence of certain subtypes of malignancy.

To assess predictors of malignancy in patients with chronic pruritus without prior dermatologic diagnoses.

Case-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.

Age 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.

Potential for misclassification and detection biases. Missing data.

In patients with chronic pruritus without concomitant dermatologic diagnoses, older age, male sex, liver disease and tobacco abuse increase the odds of an underlying malignancy.