Background Many physicians believe that the most effective way to treat chronic urticaria is to take a nonsedating second‐generation H₁‐antihistamine in the morning and a sedating first‐generation H₁‐antihistamine, usually hydroxyzine, at night to enhance sleep. But is this belief well founded? Objectives To test this belief by comparing the effectiveness and prevalence of unwanted sedative effects when treating patients with chronic spontaneous urticaria (CSU) with levocetirizine 15 mg daily plus hydroxyzine 50 mg at night (levocetirizine plus hydroxyzine) vs. levocetirizine 20 mg daily (levocetirizine monotherapy). Methods In this randomized, double‐blind, cross‐over study, 24 patients with difficult‐to‐treat CSU took levocetirizine plus hydroxyzine or levocetirizine monotherapy for periods of 5 days each. At the end of each treatment period, assessments were made of quality of life (Chronic Urticaria Quality of Life Questionnaire, CU‐Q₂oL), severity of urticaria symptoms (Urticaria Activity Score, UAS), sleep disturbance during the night and daytime somnolence. Results Both treatments significantly decreased UAS, night‐time sleep disturbances and CU‐Q₂oL scores (P < 0·001) without significant differences between the two. Compared with baseline, daytime somnolence was significantly reduced by levocetirizine monotherapy (P = 0·006) but not by levocetirizine plus hydroxyzine (P = 0·218). Direct comparison of the two treatment modalities in terms of daytime somnolence favoured levocetirizine monotherapy (P = 0·026). Conclusions The widespread belief that sleep is aided by the addition of a sedating first‐generation H₁‐antihistamine, usually hydroxyzine, at night is not supported. These results are in line with the urticaria guidelines, which state that first‐line treatment for urticaria should be new‐generation, nonsedating H₁‐antihistamines only.

Educational aims: To review the link between inflammation and increased vascularity and blood flow of the airways, and exhaled breath temperature. To position exhaled breath temperature (EBT) as a physiological characteristic differing from core temperature measured at other body sites. To review the existing experience about measuring EBT in different disease states of the respiratory system. To emphasise the influence of airway remodeling/destruction in modulating EBT. Summary: Evaluation of the exhaled breath temperature (EBT) has been suggested as a new method to detect and monitor pathological processes in the respiratory system. The putative mechanism of this approach is based upon changes in the blood flow in the conducting airways that are characteristic of different disease states, which influence the temperature of the exhaled gases. The first attempts to prove this concept were made in conjunction with measurement of exhaled nitric oxide fraction (F_eNO) about a decade ago. They made use of an open-circuit, single-breath method in a closed indoor environment, and demonstrated associations between EBT on the one hand, and bronchial blood flow,F_eNOand sputum cellular content on the other.These findings have been further extended to practical applicability with the introduction of multiple-breath, portable hand-held devices. Measurement of EBT using these is less dependent on the ambient environment and easier to perform. Studies have been conducted to explore the relationship between EBT and different physiological characteristics, and to assess possible confounding influences in the process of measurement. The value of the method has been explored in the diagnosis and monitoring of asthma, chronic obstructive pulmonary disease and other respiratory diseases. While initially, emphasis focused on airway inflammation as the primary process to be captured by this method, it was subsequently realised that destructive and other remodelling processes reducing the integral contact surface of the conducting airways and/or damaging their vasculature would also affect the end result by shifting EBT downwards. As obstructive airway disease is, in most cases, a combination of airway inflammation and remodelling/destruction, EBT should be viewed as an individual characteristic indicating fluctuating changes in the balance of these processes. Hence, an important potential application of the method is in monitoring airway diseases.EBT measurement has emerged as an attractive noninvasive new approach in respiratory and, possibly, other diseases. Systematic research will determine its place in clinical practice.