Background: Urticaria is a disorder affecting skin and mucosal tissues characterized by the occurrence of wheals, angioedema or both, the latter defining the urticaria-angioedema syndrome. It is estimated that 12-22% of the general population has suffered at least one subtype of urticaria during life, but only a small percentage (estimated at 7.6-16%) has acute urticaria, because it is usually self-limited and resolves spontaneously without requiring medical attention. This makes likely that its incidence is underestimated. The epidemiological data currently available on chronic urticaria in many cases are deeply discordant and not univocal, but a recent Italian study, based on the consultation of a national registry, reports a prevalence of chronic spontaneous urticaria of 0.02% to 0.4% and an incidence of 0.1-1.5 cases/1000 inhabitants/year. Methods: We reviewed the recent international guidelines about urticaria and we described a methodologic approach based on classification, pathophysiology, impact on quality of life, diagnosis and prognosis, differential diagnosis and management of all the types of urticaria. Conclusions: The aim of the present document from the Italian Society of Allergology, Asthma and Clinical Immunology (SIAAIC) and the Italian Society of Allergological, Occupational and Environmental Dermatology (SIDAPA) is to provide updated information to all physicians involved in diagnosis and management of urticaria and angioedema.

Some measurements of the lifetime of uv photons emitted by the excited states of argon are reported, when the excitation is obtained by the impact of the electrons in a Townsend avalanche. The measurements were made by converting the ultraviolet into visible light by means of a fluorescent screen and by observing the visible light with a photomultiplier. The results are that the energy of the uv photons is about 10 ev and that the law of emission in time is represented by the formula exp-//r^-exp-1/TM, where r^ = 3.4X10~6 sec and TM~1/9P 2 sec (^>-gas pressure in mm Hg).

Genetic diversity among T. pallidum strains circulating in Northern Italy varies significantly among geographical areas regardless of physical distance. Resistance to macrolides is widespread.

Omalizumab is approved for use in chronic spontaneous urticaria (CSU); however, it is not approved for chronic inducible urticaria (CIndU). The aim of the present study was to assess the effectiveness of omalizumab in treating CSU and CIndU in Italy. This is a multicentre prospective observational real-life study involving patients with severe urticaria capable of undergoing omalizumab therapy. We enrolled 127 patients (59.1% females), ranging in age from 15 to 83 years, 69.3% had CSU alone, 26.8% had CSU and CIndU, and 3.9% had only CIndU (30.8% delayed pressure, 35.9% dermographic, 15.3% cholinergic, 12.8% cold, 5.1% aquagenic). After the first cycle of omalizumab (300 mg every 4 weeks for 24 weeks), 16 CSU patients and 10 patients (20.5%) with CIndU with or without CSU did not require a second cycle of omalizumab (300 mg every 4 weeks for 20 weeks). The patient with aquagenic urticaria achieved remission after the first cycle. None showed a lack of response to the second cycle of omalizumab. Omalizumab is a promising drug for both spontaneous and inducible chronic urticaria. Current evidence indicates that omalizumab may be approved also for CIndU.