The prevalence of sensitization to dogs and cats varies by country, exposure time and predisposition to atopy. It is estimated that 26% of European adults coming to the clinic for suspected allergy to inhalant allergens are sensitized to cats and 27% to dogs. This document is intended to be a useful tool for clinicians involved in the management of people with dog or cat allergy. It was prepared from a consensus process based on the RAND/UCLA method. Following a literature review, it proposes various recommendations concerning the diagnosis and treatment of these patients, grounded in evidence and clinical experience. The diagnosis of dog and cat allergy is based on a medical history and physical examination that are consistent with each other and is confirmed with positive results on specific IgE skin tests. Sometimes, especially in polysensitized patients, molecular diagnosis is strongly recommended. Although the most advisable measure would be to avoid the animal, this is often impossible and associated with a major emotional impact. Furthermore, indirect exposure to allergens occurs in environments in which animals are not present. Immunotherapy is emerging as a potential solution to this problem, although further supporting studies are needed.

SummaryBackground Allergy diagnosis needs to be improved in patients suffering from pollen polysensitization due to the existence of possible confounding factors in this type of patients. Objective To evaluate new diagnostic strategies by comparing skin responses to pan-allergens and conventional allergenic extracts with specific IgE (slgE) to purified allergen molecules. Methods One thousand three hundred and twenty-nine pollen-allergic patients were diagnosed by a combination of an in vitro method with a panel of 13 purified allergens, including major allergens and pan-allergens, using a high-capacity screening technology (ADVIA-Centaur s ) and skin prick test (SPT) to pan-allergens and conventional extracts. Results There was a high concordance (k index) between in vitro (slgE to major allergens) and in vivo (SPT to conventional extracts) methods in patients who were not sensitized to panallergens, but SPT with conventional extracts failed to diagnose patients with sensitization to pan-allergens. In patients who were simultaneously sensitized to polcalcins and profilins, there was a duplication both in the number of sensitizations to major allergens and in the years of disease evolution. There was a statistical association between sensitization to profilins and/or lipid transfer proteins and food allergy (PoO.0001). Conclusion The novel diagnostic strategy has proven to be a valuable tool in daily clinical practice. Introduction of routine SPT to pan-allergens is a simple and feasible way of improving diagnostic efficacy. Patients sensitized to pan-allergens should be tested by an adequate panel of allergenic molecules in order to identify the allergens that are responsible for the allergic disease.

The type of allergic sensitization is of central importance in the diagnosis and treatment of respiratory allergic diseases. At least 10% of the general population (and more than 50% of patients consulting for respiratory allergies) are polysensitized. Here, we review the recent literature on (i) the concepts of polysensitization, paucisensitization, co-sensitization, co-recognition, cross-reactivity, cross-sensitization, and polyallergy, (ii) the prevalence of polysensitization and (iii) the relationships between sensitization status, disease severity and treatment strategies. In molecular terms, clinical polysensitization can be divided into cross-sensitization (also known as cross-reactivity, in which the same IgE molecule binds to several allergens with common structural features) and co-sensitization (the simultaneous presence of different IgEs binding to allergens that may not necessarily have common structural features). There is a strong overall association between sensitization in skin prick tests and total IgE values but there is debate as to whether IgE thresholds are useful guides to the presence or absence of clinical symptoms in individual cases. Molecular information from component-resolved techniques appears to be of value for diagnosis and treatment decisions. Polysensitization develops over time and is a risk factor for respiratory allergy (being associated with disease severity) and therefore has clinical relevance for treatment decisions. The subterm polysensitization has been defined as polysensitization to between two and four allergens. Polyallergy is defined as clinically confirmed allergy to two or more allergens. Single-allergen grass pollen allergen immunotherapy (AIT) is safe and effective in polysensitized patients, whereas multi-allergen AIT requires more supporting evidence. Given that AIT may be more efficacious in moderate-to-severe disease than in mild disease, polysensitization could be an indication for this type of treatment. There is a need for flowcharts or decision trees for choosing the allergens for AIT in polysensitized patients and polyallergic patients.

Managing patients with severe asthma during the coronavirus pandemic and COVID-19 is a challenge. Authorities and physicians are still learning how COVID-19 affects people with underlying diseases, and severe asthma is not an exception. Unless relevant data emerge that change our understanding of the relative safety of medications indicated in patients with asthma during this pandemic, clinicians must follow the recommendations of current evidence-based guidelines for preventing loss of control and exacerbations. Also, with the absence of data that would indicate any potential harm, current advice is to continue the administration of biological therapies during the COVID-19 pandemic in patients with asthma for whom such therapies are clearly indicated and have been effective. For patients with severe asthma infected by SARS-CoV-2, the decision to maintain or postpone biological therapy until the patient recovers should be a case-by-case based decision supported by a multidisciplinary team. A registry of cases of COVID-19 in patients with severe asthma, including those treated with biologics, will help to address a clinical challenge in which we have more questions than answers.