After an allergen injection, which assessment finding is most urgent for the nurse to communicate to the health care provider?

The presence of a 2-cm wheal at the site of an allergen injection is significant and warrants urgent communication to the health care provider. This finding indicates a local reaction to the allergen and could be an early sign of a more systemic allergic reaction, particularly if the wheal continues to expand or is accompanied by other symptoms such as difficulty breathing, hives, or swelling in other areas.

In the context of allergy testing or treatment, a wheal-centered reaction is expected to less extent; however, size and characteristics matter. A larger wheal could indicate a heightened sensitivity or potential for an anaphylactic reaction. Being vigilant about changes at the site of injection is critical, as immediate interventions may be required if the situation escalates.

Other findings, such as increased IgG levels or localized redness and swelling, may not require immediate action and can be monitored over time. Similarly, persistent allergy symptoms may indicate that the treatment is not effective, but they do not pose an acute risk to the patient's stability or require prompt intervention like the wheal formation might.