Pros and cons on sublingual immunotherapy in children allergic to house dust mites

Allergic asthma is a common pathology in children and house dust mites are the most frequent indoor allergens implicated 1. The Global Initiative for Asthma (GINA) guidelines has defined the management of allergic asthma, which recommends the association of allergen avoidance, pharmacologic treatment and allergen immunotherapy, when indicated 2. Immunotherapy is a specific therapeutic approach in the treatment of allergic airway disease and insect venom allergy and has been utilized for decades: it is therefore recommended to start it as soon as possible in allergic children to modify the natural course of respiratory allergy. Specific immunotheraphy (SIT) has been shown to be effective in reducing asthmatic symptoms, medication use and bronchial hyperresponsiveness 3-4. Additionally, it has been recently shown that specific immunotherapy can be also used to prevent the occurrence of new sensitizations to airborne allergens in children exclusively sensitized to house dust mites 5-6. However, subcutaneous administration of SIT is inconvenient, time and resource consuming and is occasionally associated with severe systemic side effects despites the guidelines developed for its use 7. On the other hand, sublingual immunotherapy (SLIT), which has been developed over the past 20 years, offers a better safety profile and ease of use. These advantages make it an attractive option for children 8-9. The aim of this article is to review current knowledge related to SLIT in children allergic to mites and to identify needs for future research in this field.