Explanation:
This is an anaphylactic reaction. Anaphylaxis is a Type 1 hypersensitivity reaction between an antigen and IgE bound to Mast cells in the body. This reaction causes mast cells to release histamine, leukotrienes and cytokines as well as other immunologically active agents. The release of these chemicals stimulates chemoattraction of neutrophils and eosinophils causing systemic vasodilation, increased vascular permeability, and smooth muscle spasms.

An anaphylactoid reaction is similar to anaphylaxis, however it is not mediated by IgE, and is therefore not an immune mediated reaction. In anaphylactoid reactions, the ingested material is directly responsible for the release in histamine and the other agents. While it is impossible at this point in the case to say whether this reaction was mediated by IgE or not, it is very unlikely for food to cause an anaphylactoid reaction. Most anaphylactoid reactions are caused by drugs, physical stimuli (such as cold or exercise), as well as contrast material used in radiographic studies.

Epiglottitis, croup and asthma do not fit with this clinical picture. With epiglottitis, one would expect to see a child in a tripod position, breathing with great difficulty and drooling. If the pharynx were to be examined, one would see an inflamed, erythematous epiglottis. Although epiglottis can present quickly, it does not present with systemic symptoms such as urticaria and pruritis.

Croup can present with stridor, however there would likely be a 1-4 day history of rhinorrhea, pharyngitis, and cough before the obstruction of the airway occurred. Like epiglotttitis, croup would not present with urticaria and pruritis.

Asthma also can present with stridor and light-headedness, however there are no systemic symptoms associated with asthma.