The diagnosis of anaphylaxis is often based on reported symptoms which may not be accurate and lead to major psychosocial and financial impacts. We describe two adult patients who were diagnosed as having recurrent anaphylaxis witnessed by multiple physicians based on recurrent laryngeal symptoms. The claimed cause was foods in one and drugs in the other. We questioned the diagnosis because of absent documentation of objective findings to support anaphylaxis, and the symptoms occurred during skin testing though the test sites were not reactive. Our initial skin testing with placebos reproduced the symptoms without objective findings. Subsequent skin tests with the suspected allergens were negative yet reproduced the symptoms without objective findings. Disclosing the test results markedly displeased one patient but reassured the other who subsequently tolerated the suspected allergen. In conclusion, these 2 patients' symptoms and evaluation were not supportive of their initial diagnosis of recurrent anaphylaxis. The compatible diagnosis was Munchausen stridor which requires psychiatric evaluation and behavior modification, but often rejected by patients.
Adult ; Allergens ; Anaphylaxis* ; Behavior Therapy ; Diagnosis ; Drug Hypersensitivity ; Food Hypersensitivity ; Humans ; Hypersensitivity ; Placebos ; Respiratory Sounds ; Skin Tests ; Vocal Cord Dysfunction

PURPOSE: To review the role of food additives in asthma and provide a practical approach for evaluation, diagnosis, and management of additive-induced asthma. METHODS: Information was gathered from original articles, selected reviews and abstracts published in peer-reviewed journals and from selected textbook chapters, supplemented by the clinical experience of the authors. RESULTS: In some patients, food additive ingestion can induce bronchospasm or exacerbation of symptoms in patients with chronic asthma. The most implicated agents are sulfites, followed by tartrazine, monosodium glutamate and others. However, geographic variations exist depending on the dietary habits. CONCLUSION: Food additives are worth considering as possible causes of bronchospasm or worsening of asthma. The medical history may be suggestive, particularly when symptoms occur to commercially prepared foods or to multiple unrelated foods. Physicians should also think of food additives in patients whose asthma is poorly controlled in spite of appropriate routine allergy evaluation, environmental control, and optimal pharmacologic therapy. Except for a few natural additives, allergy skin test and in-vitro tests are unreliable. A titrated oral challenge testing, preferably in a blind fashion would be the definitive diagnostic procedure.
Asthma* ; Bronchial Spasm ; Coloring Agents ; Diagnosis ; Eating ; Food Additives* ; Food Habits ; Humans ; Hypersensitivity ; Skin Tests ; Sodium Glutamate ; Sulfites ; Tartrazine