> Oral allergy syndrome (OAS), also referred to as pollen-associated FA syndrome, is a form of localized IgE mediated allergy, usually to raw fruits or vegetables, with symptoms confined to the lips, mouth, and throat. OAS most commonly affects patients who are allergic to pollens. Symptoms include itching of the lips, tongue, roof of the mouth, and throat, with or without swelling, and/or tingling of the lips, tongue, roof of the mouth, and throat.
ÎCUTANEOUS REACTIONS to foods are some of the most common presentations of FA.
> Acute urticaria is a common manifestation of FA. Lesions develop rapidly after ingesting the problem food and appear as polymorphic, round, or irregularly shaped pruritic wheals, ranging in size from a few millimeters to several centimeters.
> Angioedema most often occurs in combination with urticaria. It is characterized by nonpitting, nonpruritic, well-defined edematous swelling that involves subcutaneous tissues (for example, face, hands, buttocks, and genitals), abdominal organs, or the upper airway. When the upper airway is involved, laryngeal angioedema is a medical emergency requiring prompt assessment.
> Atopic dermatitis (AD), also known as atopic eczema, is linked to a complex interaction between skin barrier dysfunction and environmental factors such as irritants, microbes, and allergens. The role of FA in the pathogenesis and severity of this condition remains controversial. In some sensitized patients, particularly infants and young children, food allergens can induce urticarial lesions, itching, and eczematous flares, all of which may aggravate AD.
> Allergic contact dermatitis (ACD) is a form of eczema caused by cell-mediated allergic reactions to chemical haptens that are additives to foods or occur naturally in foods such as mango. Clinical features include marked pruritus, erythema, papules, vesicles, and edema.
> Contact urticaria is due to direct contact between the skin and the offending food and can be of two types: 1) IgE mediated or 2) non-IgE mediated, non- immunologic — eg, caused by direct histamine release. In IgE-mediated contact urticaria there is localized or generalized urticaria and at times systemic reactions. In non-IgE-mediated contact urticaria, systemic symptoms are rarely seen.
ÎRESPIRATORY MANIFESTATIONS occur frequently during systemic allergic reactions and are an important indicator of severe anaphylaxis. FA is an uncommon cause of isolated respiratory symptoms, namely rhinitis and asthma.
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