What is a key characteristic to observe for a child with severe upper respiratory allergies?

In the context of severe upper respiratory allergies, urticaria, commonly known as hives, is an important characteristic to observe. This skin condition occurs when the immune system responds to allergens, leading to the release of histamines that cause the skin to break out in raised, itchy welts. Severe upper respiratory allergies can trigger various allergic responses, and urticaria is a common manifestation of such immune reactions.

While decreased energy levels may also occur due to general malaise associated with allergies, urticaria directly reflects the body's heightened sensitivity to allergens and the subsequent inflammatory response. Difficulty swallowing is typically not a primary symptom of upper respiratory allergies, as it is more indicative of other conditions, such as throat inflammation, while an increased appetite typically does not correlate with the discomfort and general side effects of allergies. Thus, urticaria stands out as a key characteristic in assessing a child with severe upper respiratory allergies.