Update on the clinical features of food-induced anaphylaxis

Different clinical features of anaphylaxis according to cause and risk factors for severe reactions

BACKGROUND

Anaphylaxis is a life-threatening allergic reaction. Several studies reported different anaphylactic reactions according to the causative substances. However, a comparison of anaphylaxis for each cause has not been done. This study was conducted to identify common causes of anaphylaxis, characteristics of anaphylactic reaction for each cause and to analyze the factors related to the severity of the reaction.

METHODS

Medical records of patients who visited the emergency room of Ewha Womans University Mokdong Hospital from March 2003 to April 2016 and diagnosed with anaphylactic shock were retrospectively reviewed. We compared the clinical features of anaphylaxis according to the cause. In addition, the severity of anaphylaxis was analyzed and contributing factors for severe anaphylaxis were reviewed.

RESULTS

A total of 199 patients with anaphylaxis were analyzed. Food was the most common cause (49.7%), followed by drug reaction (36.2%), bee venom (10.1%), and unknown cause (4.0%). Cardiovascular symptoms of syncope and hypotension were more common in drug-induced anaphylaxis. The incidence of severe anaphylaxis was the highest in anaphylaxis due to drugs (54.2%). Urticaria and other skin symptoms were significantly more common in food-induced anaphylaxis. Risk factors for severe anaphylaxis included older age, male, and drug-induced one. Epinephrine treatment of anaphylaxis was done for 69.7% and 56.9% of patients with food-induced and drug-induced anaphylaxis, respectively.

CONCLUSIONS

More severe anaphylaxis developed with drug treatment and in males. Low rate of epinephrine prescription was also observed. Male patients with drug induced anaphylaxis should be paid more attention.

Mouse models of food allergy: how well do they simulate the human disorder?

Food allergy is a growing health problem with serious concerns due to high potential for fatality. Rapid advances in the knowledge on causes and mechanisms as well as in developing effective prevention/therapeutic strategies are needed. To meet these goals, mouse models that simulate the human disorder are highly desirable. During the past decade, several mouse models of food allergies have been reported. Here, we briefly reviewed the human disorder and then critically evaluated these models seeking answers to the following important questions: To what extent do they simulate the human disorder? What are the strengths and limitations of these models? What are the challenges facing this scientific area? Our analysis suggest that: (i) the mouse models, with inherent strengths and limitations, are available for many major food allergies; there is scope for additional model development and validation; (ii) models mostly simulate the severe forms of human disorder with similar immune and clinical features; (iii) the approaches used to develop some of the mouse models may be questionable; and (iv) the specific mechanisms of sensitization as wells as oral elicitation of fatal reactions in both humans and mice remains incompletely understood and therefore warrants further research.

Effect of oral sodium cromoglycate in 2 children with food-dependent exercise-induced anaphylaxis (FDEIA)

Food-dependent exercise-induced anaphylaxis (FDEIA) was prevented from recurring in 2 children by sodium cromoglycate (SCG) before intake of the causative food. CASE 1: A 14-year-old girl who had suffered recurrent symptoms of anaphylaxis when she exercised after lunch. Radioallergosorbent test (RAST) was 1.49 UA/mL for wheat. She was advised to take SCG before lunch. In 2007, she ate bread at lunchtime without taking SCG and developed anaphylaxis. After this, she always took SCG and did not develop anaphylaxis. CASE 2: A 9-year-old boy who had recurrent symptoms of anaphylaxis when he exercised after lunch. RAST was 0.46 UA/mL for wheat. He started taking SCG before lunch. In June 2008, he forgot to take SCG and ate fu (a food made from wheat). He exercised after lunch and developed anaphylaxis. Since then, he has always taken SCG and has not developed anaphylaxis.

CONCLUSION

Our findings suggest that SCG prevents FDEIA caused by wheat allergy.

Pediatric atopic dermatitis: the importance of food allergens

Food allergy and atopic dermatitis often occur in the same patients. Food-induced eczema may be perceived as a controversial topic because the immunologic mechanisms have yet to be fully elucidated. Nevertheless, published clinical studies have clearly demonstrated that foods can induce symptoms in a subset of patients with atopic dermatitis. Those at greatest risk are young children in whom eczematous lesions are severe or recalcitrant to therapy. Allergy testing can be helpful but must be applied judiciously. A medical history obtained by a skilled and knowledgeable health care provider is of paramount importance to interpret test results appropriately. Finally, the implementation of proper dietary avoidance can improve symptoms and provide safety from potentially fatal anaphylaxis. However, if inappropriate prescribed, elimination diets can have significant negative nutritional and social consequences.

Food allergy: diagnosis, treatment, prognosis, and prevention

Primary care providers are advised to refer to an allergist those children in whom they suspect a food allergic reaction. Approximately 6% of U.S. children have food allergy, although many more parents will present with concerns of a food-induced condition. At higher risk are young children with atopic dermatitis. Generally, the stronger the test response (wheal size or sIgE concentration), the more likely there is to be clinical allergy. However, testing must be applied judiciously. Most importantly, the medical history must be considered in order to interpret test results appropriately. Avoidance of the offending food allergen is currently the only way to prevent reactions. Because exposures and reactions can occur unexpectedly, patients and their families must be prepared to treat symptoms quickly with intramuscular epinephrine in the lateral thigh. Hopefully, additional treatment options will become available in the near future to ease the anxiety and fearfulness that parents and patients face on a daily basis. Until then, healthcare providers are urged to demonstrate the correct administration of autoinjectable epinephrine using a placebo device and review the technique with families on an ongoing basis.

Cardiovascular responses in patients with acute allergic reactions treated with parenteral epinephrine

The present study describes the cardiovascular responses to epinephrine (Epi) given into the arm, in adult patients with acute allergic reactions, and the differential responses to subcutaneous (SC) and intramuscular (IM) administration. Sixty-three adult patients were treated with Epi administered SC or IM after H1 and H2 receptor blockade. Heart rate and blood pressure (BP) were then measured for 20 minutes. Changes in heart rate and BP variables were analyzed. Pulse pressure and systolic BP showed increases with time. Diastolic BP also showed a modestly decreasing values over time. Heart rates did not change. Time-related changes between IM and SC Epi treatment were not observed. Sex influenced timed BP values and a significant sex by time effect was observed. In subset analysis, only male patients showed an overall time effect for BP variables, especially pulse pressure. In conclusion, adults with acute allergic syndromes treated with arm-injected Epi show a modest but definite increase in pulse pressure and systolic BP. This pattern is observed more in males. Heart rate and blood pressure differences between IM and SC arm-injected Epi treatments do not appear to be significant.

The diagnosis and management of anaphylaxis

Anaphylaxis is amongst the most frightening reactions that any physician will face. What often separates life and death is the acute management, including the proper use of epinephrine. In this review, the differential diagnosis and management plan are outlined.