Food allergy is a growing concern, and recognition of symptoms, knowledge of common food allergens, and management of reactions are important for patients and practitioners. Symptoms of a classic IgE-mediated food allergy vary in severity and can include any combination of laryngeal edema, wheezing, nausea, vomiting, diarrhea, urticaria, angioedema, and hypotension. Many foods can induce an allergic reaction, but the most commonly implicated foods include cow's milk, egg, peanut, tree nut, soy, wheat, fish, and shellfish. Milk and egg allergy generally develop and are outgrown in childhood. Peanut and tree nut allergy can occur during childhood or adulthood, are less likely to be outgrown, and tend to cause more fatal reactions. Given the possibility of life-threatening reactions, it is important to recognize the potential for cross-reactivity among food groups. Diagnosis of food allergy includes skin prick testing, specific serum IgE testing, and oral food challenges. Management is centered on avoidance of allergenic and cross-reacting foods and early recognition and immediate treatment of reactions. Treatment protocols to desensitize patients to food are currently under investigation.

BACKgrOUND: Atropine is a widely used anticholinergic drug. Its topical use is mainly restricted to ophthalmologic preparations, chiefly as mydriatic eye drops. Usually well tolerated, eye dryness, blurred vision and increased intraocular tension are the main adverse effects; allergic reactions are uncommon. CASE REPORT: A 71-year-old woman had a left corneous sore. Ten days after beginning treatment with atropine eye drops, she presented with conjunctival erythema and pruritus and ipsilateral facial aedema. RESULTS: Patch test with benzalconio-clorure (0.1% pet), thiomersal (0.1% pet), etilendiamine (1% pet), parabens (16% pet), phenylephrine (10% DMSO), cyclopentolate (Colicursi Cicloplejico®), tropicamide (Colicursi Tropicamida®) and with the chemically related mydriatic, hyoscine (Buscapina Boehringer Ing® 20 mg/ml), were negative. Patch test with atropine drops (Colircusi 0.5%®) and parenteral atropine (Braun Medical® 1 mg/ml) turned positive in 48 hours. Single blind challenge test with ocular cyclopentolate, phenylephrine, tropicamide and oral hyoscine were negative. CONCLUSIONS: We present a case of allergic conjunctivitis and facial aedeme caused by atropine. The positive patch test revealed a delayed hypersensitivity mechanism. Cross reactivity was absent between atropine and hyoscine.