Effects of Omalizumab on Rhinovirus Infections, Illnesses, and Exacerbations of Asthma.

RATIONALE: Allergic inflammation has been linked to increased susceptibility to viral illnesses, but it is unclear whether this association is causal. OBJECTIVES: To test whether omalizumab treatment to reduce IgE would shorten the frequency and duration of rhinovirus (RV) illnesses in children with allergic asthma. METHODS: In the PROSE (Preventative Omalizumab or Step-up Therapy for Severe Fall Exacerbations) study, we examined children with allergic asthma (aged 6-17 yr; n = 478) from low-income census tracts in eight U.S. cities, and we analyzed virology for the groups randomized to treatment with guidelines-based asthma care (n = 89) or add-on omalizumab (n = 259). Weekly nasal mucus samples were analyzed for RVs, and respiratory symptoms and asthma exacerbations were recorded over a 90-day period during the fall seasons of 2012 or 2013. Adjusted illness rates (illnesses per sample) by treatment arm were calculated using Poisson regression. MEASUREMENTS AND MAIN RESULTS: RVs were detected in 97 (57%) of 171 exacerbation samples and 2,150 (36%) of 5,959 nonexacerbation samples (OR, 2.32; P < 0.001). Exacerbations were significantly associated with detection of rhinovirus C (OR, 2.85; P < 0.001) and rhinovirus A (OR, 2.92; P < 0.001), as well as, to a lesser extent, rhinovirus B (OR, 1.98; P = 0.019). Omalizumab decreased the duration of RV infection (11.2 d vs. 12.4 d; P = 0.03) and reduced peak RV shedding by 0.4 log units (95% confidence interval, -0.77 to -0.02; P = 0.04). Finally, omalizumab decreased the frequency of RV illnesses (risk ratio, 0.64; 95% confidence interval, 0.49-0.84). CONCLUSIONS: In children with allergic asthma, treatment with omalizumab decreased the duration of RV infections, viral shedding, and the risk of RV illnesses. These findings provide direct evidence that blocking IgE decreases susceptibility to RV infections and illness. Clinical trial registered with www.clinicaltrials.gov (NCT01430403).

Anaphylaxis Conundrum: A Trojan Horse Phenomenon.

Anaphylaxis is a serious and potentially life-threatening allergic reaction that may follow the ingestion of foods. Although these reactions usually follow a common clinical pattern and often demonstrate IgE sensitization to the antigen in question, both the clinical presentation and causative allergen may be atypical, surprising, and difficult to identify. Failure to identify the actual cause of the reaction can compromise treatment and complicate long-term care. Here, we present a patient who had symptoms of anaphylaxis after eating salmon, but confirmation of the causative allergen was not readily apparent. This particular case serves as an insightful lesson for patients undergoing evaluation for anaphylaxis and also provides a framework for navigating through a case involving identification of an underlying allergen.

Multisystem reactions during egg oral food challenges may be associated with less severe reactions on initial presentation.

In this study, we assessed whether multisystem reactions to egg and extensively-heated (EH) egg during OFCs were associated with a history of multisystem reactions. Records of children, who underwent OFC to egg or EH egg over a five-year period were reviewed. Of the 120 challenges, 26 (21.67 %) failed, with 38.4 % (10/26) having multisystem reactions. Of the 13 who had multisystem reactions on initial presentation, only two (15.4 %) had a similar OFC outcome. Eighty percent (8/10) of those who had a multisystem OFC reaction had a less severe initial presentation. Initial and OFC multisystem reactions were not associated with each other.