Risk Factors in Severe Anaphylaxis: Which Matters The Most, Food or Cofactors?

BACKGROUND AND OBJECTIVE

The prevalence of anaphylactic shock, the most severe manifestation of anaphylaxis, remains unknown. Risk factors and biomarkers have not been fully identified. Objective: To identify risk factors in anaphylactic shock patients.

METHODS

Using lipid transfer protein (LTP)allergy as a model, the characteristics of patients who developed anaphylaxis and anaphylactic shock were compared. Demographics, pollen sensitization, foods ingested up to 2 hours before the reaction onset, and the presence of a cofactor were recorded. Culprit foods were identified by compatible clinical history and positive allergological work-up (skin prick test and/or sIgE).

RESULTS

150 reactions were evaluated, suffered by 55 patients with An (134 reactions) and 12 with AnS (16 reactions). Patients in the anaphylaxis group experienced twice as many reactions (mean [SD] 2.4[2.5] in An vs 1.3[1.5) in AnS, p<0.02). No relationship between any food group and reaction severity was found. The most frequent food involved in both groups of patients was the combination of several plant-derived foods ("plant food mix"), followed by peach and nuts. Indeed, in the "plant food mix" reactions the presence of a cofactor was more often observed than in other food groups. On the other hand, cofactors were not present in peach- and nuts-related reactions. Exercise was the most frequent cofactor in all groups.

CONCLUSION

In our series, the severity of the reactions was not determined by the kind of food or presence of a cofactor. Anaphylactic shock seems an infrequent presentation that may be related with other individual-related factors that need further evaluation.

Therapeutic Strategy According to Differences in Response to Omalizumab in Patients With Chronic Spontaneous Urticaria

Chronic spontaneous urticaria (CSU) is a heterogeneous condition that can severely impact quality of life. Consequently, rapid disease control is essential. First-line treatment of the symptoms of CSU is the licensed dose of second-generation H1 antihistamines. For second-line treatment, this dose may be increased by up to 4 times. In patients who fail to respond to higher doses of H1 antihistamines, omalizumab for up to 24 weeks is recommended to achieve disease control. After this 24-week period, the patient's response to omalizumab should be assessed in order to identify refractory patients. Optimal management of refractory patients has not been established. Therefore, the aim of the present consensus document, which was drafted by allergists and dermatologists with specific expertise in treating urticaria, was to define specific patient profiles based on differences in their response to omalizumab. We also developed a treatment algorithm based on the specific response profile. After a comprehensive literature review, a group meeting was held to discuss issues related to the therapeutic management of patients with CSU that had not been addressed in previous studies. The experts considered both the available evidence and their own clinical experience with omalizumab. We believe that implementation of the proposed algorithm will optimize management of CSU patients who are refractory to antihistamines, reduce disease-related costs, and improve quality of life.