Fever was the leading cause of medical consultation in children, accounting for 15–25% of all primary care and emergency departments visits. In this case, a 13-year-old girl presented with an odd fever presentation and was misdiagnosed with a recurring urinary tract infection for 8 years. A case study was conducted for the Clinical Reasoning Cycle. A 13-year-old girl was referred with periodic fevers dating back to 8. The patient suffered a 5-day high-grade fever with loss of appetite during the first febrile episode. Physical examination was ordinary at the time. Blood testing revealed leukocytosis with a leftward shift, and a urine check revealed pyuria. Bacterial growth was detected in the urine culture. Every 45 days, the fever bouts were repeated. The patient was diagnosed with a recurring urinary tract infection as a result. The patient was healthy, and laboratory values were typical in the intervals between febrile episodes. The scans for ultrasonography, voiding cystourethrogram, and dimercaptosuccinic acid was all normal. The patient had difficulties swallowing on the last visit, and an examination revealed cervical lymph nodes, exudative tonsillitis, and painful aphthous stomatitis. Corticosteroids were started once all antibiotics were finished. The patient’s symptoms improved, and the time between febrile episodes grew longer. The results demonstrate that a patient should never be marked, especially if the signs and indicators don’t fully explain the patient’s condition.