March 2021

Chronic urticaria is a frequent disease and represents a large burden for many patients because symptoms are often not adequately controlled. Evidence-based diagnosis and treatment of urticaria are part of the existing guidelines. However, these do not address some questions from everyday clinical practice. This study aimed to summarize the results from a digital meeting held in May 2020, where specialists discussed the practical aspects of chronic urticaria to formulate supporting aids for everyday clinical treatment.

It is known that the diagnosis of chronic urticaria is prompt by a physical examination, anamnesis, and laboratory testing, and treatment should be performed similarly, whether there are wheals, angioedema, or both. A second-generation non-sedating H1 antihistamine is the first treatment of choice. If urticaria doesn’t clear in two to four weeks, a higher dosage is recommended. If there is no improvement after two to four weeks, additional treatment with approved IgE antibodies, such as omalizumab should be administered.

When there is no therapeutic success after six months of treatment with omalizumab, it is recommended an off-label treatment with cyclosporin A in addition to existing therapy with H1 antihistamines. In case of acute exacerbations, oral-systemic glucocorticoids can be given up to 10 days to decrease duration and activity.

In conclusion, these recommendations add on to the existing treatment guidelines and support clinical practice with people with chronic urticaria, with the objective to help them live with no symptoms and a better quality of life, ensuring that the treating physician provides good documentation and education to the patient about off-label use of drugs.

Some studies demonstrate that psychoactive drugs may protect from SARS-CoV-2 infection. H1 antihistamines and cationic amphiphilic drugs (CAD) have been identified as potentially effective against coronavirus. CAD lead to intracellular trafficking disturbances, which disrupt viral entry and replication.

Many antihistamines are also CAD, acting on both virus entry and exerting a negative regulation on IL-6 release from human lung macrophages, which are secreted in great amounts during the cytokine-storm of COVID-19.

H1 antihistamines in general and phenothiazines and derivates, in particular, can represent a useful strategy against SARS-CoV-2 at different stages, from the prophylaxis to complications’ prevention. Also, a sample of 219000 health records demonstrated that three antihistamines (azelastine, diphenhydramine, and hydroxyzine) were associated with reduced incidence of SARS-CoV-2 in people older than 61.

Although more recent studies suggest that a psychiatric disorder can increase the risk of COVID-19 or developing a severe form, the authors came to the assumption that mental health patients, once hospitalized due to COVID-19, have their risk increased due to the possible reduction or interruption of medications with a potential effect against SARS-CoV-2.

In conclusion, the best tolerated drugs with few side effects can become prophylactic candidates to reduce the risk of infection by SARS-CoV-2 in the general population. However, the benefit-risk should always be assessed.