Generalized Pruritus

Background:Generalized pruritus can often be the primary manifestation of systemic disease. Objective:To determine how frequently generalized pruritus had a systemic etiology in an outpatient population seen in a dermatology department and whether any identifiable patient characteristics meant a systemic explanation of generalized pruritus was more likely. Methods:A prospective controlled study of 55 patients with generalized pruritus and 41 healthy age- and sex-matched control subjects. Clinical data were collected from patients and laboratory parameters investigated in both patients and healthy control subjects to determine the frequency of systemic disease in each group. Results: Of 55 patients, 12 had a systemic cause of pruritus. Pruritus was the initial symptom of systemic disease in eight of these patients. The underlying diseases included hypothyroidism, chronic lymphocytic leukemia, hepatitis C, hepatitis B, diabetes mellitus, lung cancer, uremia, and iron deficiency anemia. Of these, iron deficiency anemia was the most common cause. Compared with the control group, mean serum hemoglobin, iron, and cyanocobalamin (vitamin B₁₂) levels in patients with generalized pruritus were lower. No other patient characteristics were statistically associated with systemic causes of pruritus. Conclusion:Generalized pruritus was the initial symptom of a systemic disease in 8 of 55 patients presenting to a dermatology outpatient clinic with this complaint. A number of underlying diseases were identified, of which the most common was iron deficiency anemia.