The Symptomatology of Fever: A Step Towards Qualitative Definition of Fever

Background: The old definitions of fever are based on cross-sectional surveys of the population without analyzing the associated symptomatology as fever is a sign, not symptom. Therefore, a longitudinal follow-up study is the need of hour to analyze associated symptoms with fever.

Methods: In a longitudinal study over one year, 196 participants recorded three temperature readings daily, one after waking up, one between 12 and 3 PM, one before sleeping, and filled the symptomatology questionnaire in a thermometry diary.

Results: Per protocol analysis was done for febrile participants (n = 144). Fatigue (50.3%), warmth (47.3%), headache/head heaviness (47.0%), feeling malaise/general weakness (46.7%), loss of appetite (46.5%), muscle cramps/muscle aches (45.6%), chills/shivering (44.6%), increased sweating (43.0%), nausea (42.5%), irritability (38.9%), increased breathing rate (37.1%), and restlessness/anxiety/palpitations (36.5%) were the symptoms maximally seen during the febrile phase. A higher number of associated symptoms are associated with higher temperature readings. Dehydration suggested the numerically highest temperature values (100.86 ± 1.70°F) but seen in few febrile patients.

Conclusions: Incorporation of symptom analysis in febrile patients is the need of the hour. Fatigue and warmth are found to be the most prevalent symptoms during febrile phase. Associated symptoms can help in predicting the intensity of fever also.