Demographic and clinical characteristics of chronic histaminergic angioedema and chronic urticaria with angioedema, a multicenter Italian experience

<b>Background.</b> Chronic spontaneous urticaria (CSU) is a common disorder characterized by the recurrence of wheals and/or angioedema for more than 6 weeks. About 35% of patients experience wheals and angioedema (AE-CSU) and around 6% of patients only present angioedema, also known as chronic histaminergic angioedema (CHA). As few data comparing CHA and AE-CSU are published, we analyzed the differences between demographic and clinical characteristics of these populations. <b>Methods.</b> A multicenter, observational, retrospective study, involving eight Allergology Centers in Lombardy, Italy, including 44 CHA and 34 AE-CSU pediatric and adult patients was performed. Data about sex, age, comorbidities, inflammatory markers, complement fractions, blood count, use of ACE inhibitors or angiotensin receptor blockers, site of angioedema attacks, therapy used to treat attacks, frequency of attacks at diagnosis, after 6 months of therapy and after 12 months of therapy were collected and analyzed. <b>Results.</b> A higher rate of atopy was found in AE-CSU than in CHA (58.8% <i>vs</i> 29.5%, p = 0.01). Hypothyroidism and antithyroid antibodies were more frequently detected in AE-CSU (p < 0.05). Face was the site majorly involved in both populations. Tongue angioedema was more reported in CHA than AE-CSU (22.7% <i>vs</i> 2.9%, p = 0.019). In CHA patients, upper airway involvement was reported mainly in male patients (p = 0.02). Monthly frequency of angioedema attacks at diagnosis was higher in AE-CSU than in CHA (2.1 <i>vs</i> 1.45, p = 0.045). <b>Conclusions.</b> Some characteristics may differentiate CHA from AE-CSU, as the latter experience higher rates of atopy, hypothyroidism and anti-thyroid antibodies positivity, as well as higher frequency of attacks and less tongue involvement.