In children with allergic asthma, subcutaneous immunotherapy (SCIT) may reduce long-term asthma medication use, a systematic review published in the journal Pediatrics suggests.

Allergen immunotherapy (AIT) can be given as SCIT or as one of the four sublingual immunotherapy (SLIT) tablets (house dust limit, 5-grass, Timothy grass, and ragweed) approved by the US Food and Drug Administration for allergic rhinitis.

Dr. Jessica L. Rice from Johns Hopkins University School of Medicine, in Baltimore, Maryland, and colleagues summarize the current evidence for the efficacy and safety of SCIT and SLIT in pediatric allergic asthma in their current systematic review.

Overall, there was a moderate strength of evidence (SOE) that SCIT may improve long-term controller medication use. There was low SOE that SCIT improves quick-relief-medication use, asthma-related quality of life and systemic corticosteroid use.

There were inconsistent results regarding the effects of SCIT on pulmonary physiology, as measured by FEV1.

For SLIT, there was insufficient evidence about its effect on systemic corticosteroid use and consistent evidence that it does not reduce quick-relief or long-term control-medication use. There was low SOE from six trials with inconsistent results on the impact of SLIT on FEV1.

Adverse local and systemic reactions (including anaphylaxis) occurred more frequently with both SCIT and SLIT than with treatments used in comparator arms of the studies reviewed.

"Per the practice guidelines, AIT should be administered in a setting that can monitor for and manage adverse reactions, and patients should be monitored for 30 minutes after therapy (this includes the first dose of SLIT)," the authors explain.

"After the first dose, SLIT can be administered at home. Patients administering SLIT at home should, however, be instructed on how to manage adverse reactions and situations when SLIT should be held."

"In our review, we did not find studies in which researchers evaluated the effect of single versus multiple allergen AIT in patients who are polysensitized, which is an important clinical question to address in future trials," the researchers write.

Dr. Richard F. Lockey of the University of South Florida College of Medicine in Tampa, said that AIT "should be utilized when possible, because it is a 'natural' way of creating tolerance to the allergens to which an asthmatic is allergic, thus improving their asthma and also their allergic rhinoconjunctivitis."

"Allergen immunotherapy has been utilized for years, and we are now getting more and more information about how it works, its efficacy, and the pros and cons of SCIT vs. SLIT and the best patients for which it is indicated," said Dr. Lockey.

"Only one in 10 allergic subjects are placed on such therapy in our clinic. So it should be used judiciously. There is risk with SCIT; that is why it should be prescribed by board-certified allergy/immunology physicians who know the risk-benefit."

Dr. Antonella Muraro, chair of the European Academy of Allergy and Clinical Immunology (EAACI) Allergen Immunotherapy Guidelines from the University of Padua, Italy, said, "AIT can represent an effective treatment at an early stage in allergic asthmatic children using validated symptoms scores to monitor outcomes. Clinical care pathways should include allergen immunotherapy as a treatment option in pediatric allergic asthma."