What defines a moderate allergic reaction?

A moderate allergic reaction is characterized by symptoms that are more pronounced than mild reactions, but do not reach the severity of anaphylaxis. The correct answer highlights that symptoms can include a more extensive rash, moderate swelling, and gastrointestinal symptoms. These manifestations suggest a body response to allergens that is significant enough to require recognizing and monitoring but does not pose an immediate life threat like anaphylaxis would.

Anaphylaxis and shock, as mentioned in the first choice, are defining characteristics of a severe allergic reaction, making that option unsuitable for moderate reactions. Symptoms affecting only the respiratory system, indicated in the third choice, are too restrictive and do not encompass the range of symptoms typically associated with moderate reactions. The final option suggests a lack of symptoms and merely discomfort, which does not characterize the moderate level of response seen in allergic reactions. Thus, the presence of more extensive symptoms in option B articulates the essence of what constitutes a moderate allergic reaction.