Remitting fever of unknown origin in a 20‐year‐old man

Abstract

A 20-year-old man presented with a 12-month history of intermittent febrile episodes; remitting arthritis of the wrists, knees, and lower legs; and disabling myalgia during an attack. He also reported transient erythema on the arms and legs during an attack. Fever and erythema seemed to respond to oral antibiotic therapy and acetaminophen, but arthralgia and myalgia disappeared only slowly. The patient had no signs of oropharyngeal, gastrointestinal, bronchopulmonal, or urogenital infection. Further attacks occurred every 1 to 2 months with identical symptoms and course. The duration of each attack was 3 to 4 days and he was completely asymptomatic between the attacks. Because of the rapid rise and decline of the Creactive protein (CRP) level (Figure 1) and the uniform presentation of the attacks, we had doubts whether the observed partial response to oral antibiotics was really a causal relationship. An autoinflammatory syndrome was suspected and the patient took colchicine 0.5 mg twice a day to prevent further attacks. However, due to gastrointestinal side effects he had to discontinue colchicine after 1 day and we could not evaluate the efficacy of colchicine. A trial of anakinra was initiated during the following attack. Despite significant improvement of all symptoms, including the debilitating myalgia, the fever recurred after a few days and the patient was admitted to the hospital to reevaluate the diagnosis. Medical HistoryThe patient had atopic dermatitis during early childhood, which resolved after a few years. At age 10 years he experienced an episode with fever, reduced global health, distinct purpura on both legs and the lower trunk, severe headache, vomiting, and signs of meningitis. A lumbar puncture finally revealed a positive culture for Neisseria meningitidis. With antibiotic therapy, he recovered rapidly without any persisting symptoms. He did not report any other severe infections and he was not more frequently affected by common infections. Social and Family HistoryThe patient was born in Germany and his family originated from an Eastern European country. His mental development was unremarkable. After secondary school he began working as a storekeeper. The medical history of his 16-year-old sister, his parents, and other relatives was unremarkable. Physical ExaminationThe patient had an athletic stature (height 183 cm, weight 70 kg) and appeared uncomfortable and weak. He was febrile with a temperature of 40°C in the morning and he experienced increasing pain in his left foot for 2 weeks. The pain level reached 3 of 10 during rest and 7 of 10 during exercise. He did not have headaches. Ibuprofen 400 mg reduced the fever but not the pain. Mild swelling appeared at the tendons on the back of his left foot. The sole of the left foot was painful during walking, indicating tenosynovitis of the flexor and extensor tendons of the left foot. The muscles at the cervical spine appeared painful upon palpation. No signs of meningitis, arthritis, exanthema, purpura, serositis, or hepatosplenomegaly were ...