What finding would likely indicate a severe infection in a case of malignant otitis externa?

A fever is a key clinical sign that often indicates a severe infection, particularly in the context of malignant otitis externa, which is a serious infection that can affect the outer ear and surrounding tissues. In this condition, the body responds to the infection by raising its temperature in an effort to combat the pathogens, which is a common physiological response.

While decreased appetite, chronic dehydration, and fatigue can be associated with infections or other illness, they are not specific indicators of the severity of an infection in the same way that fever is. Decreased appetite may result from a range of factors, including general malaise or other health conditions. Chronic dehydration might be a consequence of prolonged illness or inadequate fluid intake, not solely related to the severity of an infection. Fatigue can occur due to various reasons, including inflammatory responses, but again, it does not uniquely signify a severe infectious process.

Thus, the presence of a fever in a patient with malignant otitis externa highlights a more immediate and significant concern regarding the potential for widespread infection or serious disease progression, making it an important finding for diagnosis and management.