Clinical characteristics of pruritus in chronic idiopathic urticaria.

Abstract

Although pruritus is a predominant symptom of chronic idiopathic urticaria (CIU) its clinical characteristics have not been explored. To characterize the clinical pattern and sensory and affective dimensions of the itch experience, utilizing a comprehensive itch questionnaire. A structured questionnaire based on the McGill pain questionnaire was used in 100 patients suffering from CIU randomly recruited from a tertiary referral centre. All 100 patients recruited with CIU completed the questionnaire. In 68 patients pruritus appeared on a daily basis. Most patients experienced their pruritus at night and in the evening (n = 83), and 62 reported difficulty in falling asleep. Pruritus involved all body areas, but mostly the arms (n = 86), back (n = 78) and legs (n = 75). Accompanying symptoms were a sensation of heat in 45 patients and sweating in 15. Most patients (n = 98) were prescribed antihistamines (mainly sedating), of whom 34 experienced long-term relief. The sensation of itch was reported to be stinging (n = 27), tickling (n = 25) and burning (n = 23). Seventy-six patients found their pruritus bothersome, 66 annoying and 14 complained of depression. The itch intensity at its peak was more than double that felt after a mosquito bite. The worst itch scores of those who felt depressed were significantly higher than of those who did not (P = 0.018). There was a positive correlation between the sensory and affective scores during worst itch (P < 0.001). This study describes the itch experienced in CIU, highlighting sensory and affective dimensions. The itch questionnaire was found to be a valuable tool for evaluating pruritus in CIU and its unique features.