Allergic rhinitis symptoms became worse for nearly 40% of patients in the COVID-19 lockdown due to greater exposure to indoor allergens
Allergic rhinitis (AR) symptoms worsened for around 40% of patients during the first COVID-19 lockdown, probably because of greater exposure to indoor allergens according to a study by researchers from Fundacion Santa Fe de Bogotá, Columbia.
Allergic rhinitis affects 15 to 25% of the population and is characterised by symptoms such as sneezing, itching, nasal congestion and rhinorrhoea. Allergy avoidance is an effective management strategy for those with seasonal allergic rhinitis and usually, those with hayfever are symptom-free outside the pollen season. In contrast, allergy avoidance for individuals with house dust mite-sensitive AR is more difficult given the presence of mites in the home. In fact, one Italian study has shown that during the first COVID-19 lockdown, this negatively influenced the clinical history of patients with dust mite allergy. In terms of management, allergen-specific immunotherapy (allergen-SIT) is the only known treatment able to alter the natural course of allergic rhinitis.
But to what extent did the COVID-19 national lockdown and the abrupt cessation of SIT impact on overall symptom control in patients with AR? This was the subject of the present study by the Columbian researchers. They performed an observational study between March and May 2020 to assess any changes in AR symptoms in patients with a clinical diagnosis of AR and who were treated with monthly depot SIT injections for at least 6 months. The team used a visual analogue scale (VAS) from 0 (no symptoms) to 10 (severe symptoms) to assess the main AR symptoms including nasal obstruction, pruritus, rhinorrhoea and ocular symptoms. In addition, trained researchers used a sociodemographic questionnaire to collect further information on participants, for instance, age, education level, income, floor material in the household, number of household members etc.
Allergic rhinitis and symptom control
A total of 318 individuals with a mean age of 18.9 years (55.1% female) were included in the analysis. The median number of immunotherapy doses before the lockdown was 11 with a median of 3 doses missed during isolation.
Overall, 38.4% reported that their symptoms worsened during the lockdown period and this was apparent for all AR symptoms. For example, for nasal obstruction, 69.6% stated that their symptoms worsened compared to 30.4% who reported that their symptoms improved or remained the same. A pre-post mean difference in the VAS of 0.5 was found for nasal obstruction (p = 0.01) and pruritus (p < 0.001), a 0.7 difference for rhinorrhoea (p < 0.001) and 0.8 for ocular symptoms (p < 0.001).
Factors associated with a reduction in the final VAS scores were the presence of dogs and cats in the house, atopic dermatitis, lower levels of education and a lower number of immunotherapy doses prior to the lockdown.
The authors concluded that the worsening of AR symptoms during the COVID-19 lockdown was likely to be attributable to a higher exposure to indoor allergens and the interruption of immunotherapy, highlighting the importance of environmental factors in the pathogenesis of the disease.
Pérez-Herrera LC et al. Impact of the COVID‐19 national lockdown in the allergic rhinitis symptoms in patients treated with immunotherapy at two allergy referral centers in Bogotá, Colombia Laryngoscope Investig. Otolaryngol 2022