Subacute Thyroiditis Causing Fever of Unknown Origin: A Reminder of the Uncommon Cause.

Subacute thyroiditis (SAT) is a transient inflammation of the thyroid gland that often occurs following a viral infection. It is an infrequent cause of fever of unknown origin (FUO). We present a 46-year-old gentleman who presented with two weeks of fever and some non-specific left-sided neck pain. His initial investigations and microbiological workup were unremarkable. He did not report any hyperthyroid symptoms. A computed tomography of the neck, chest, abdomen, and pelvis showed a heterogeneous appearance of his thyroid gland. Thyroid function was then performed, and it showed primary hyperthyroidism. His thyroid autoantibodies were negative. Ultrasonography of his thyroid showed features consistent with thyroiditis. He was treated with a course of oral steroids. His fever lysed. His thyroid function turned from a primary hyperthyroid pattern to subclinical hypothyroidism. His anti-thyroglobulin antibody level remained elevated after the steroid treatment. Our case highlights that SAT is an uncommon cause of FUO in patients without specific localizing symptoms. It can present without overt hyperthyroid clinical features. Steroid treatment is useful. There may be value in monitoring the anti-thyroid antibodies in SAT's management.

A Rare Case of Kikuchi-Fujimoto Disease.

Kikuchi-Fujimoto disease (KFD) is an autoimmune condition that is more common in females and occurs in the third decade of life. The condition is usually benign and self-resolving and is characterized by fever, cervical lymphadenopathy, night sweats, myalgia, and rashes. The disease can be misdiagnosed as reactive follicular hyperplasia, tuberculous lymphadenitis, systemic lupus erythematosus, and malignant lymphoma. The diagnosis of KFD involves the excision of the affected lymph node. Although there is no specific treatment for the disease, usually symptomatic and supportive measures are effective; however, steroids and immunosuppressive therapies are considered in more severe cases. The disease lasts for around one to four months. The neurological complications include cerebellar ataxia, meningoencephalitis, and aseptic meningitis. Here, we describe the case of a 36-year-old male who presented with complaints of fever, malaise chills, anorexia, and fatigue associated with a tender right axillary lymph node. The patient underwent a biopsy which confirmed KFD and responded well to supportive therapy.

Too Hot to Handle: A Case of Fever of Unknown Origin.

Fever of unknown origin (FUO) is defined as a fever higher than 38.3ºC for at least three weeks. It remains a difficult diagnostic challenge and it carries well over 200 differential diagnoses, including infectious, rheumatologic and malignant etiologies. A methodological approach with clinical deductive reasoning and value-based investigative work-up can establish the diagnosis. This case is about a 76-year-old male with a past medical history of atrial fibrillation, bladder cancer treated with chemotherapy (now in remission) and hydronephrosis with recent ureteropelvic junction stent placement. He presented to the emergency department (ED) for worsening shortness of breath (SOB), weakness, and fevers. His initial workup was notable for a urinary tract infection which was treated with ceftriaxone. However, there was only a limited improvement in the fever. Diagnostic imaging was negative on initial review. He was evaluated by consultants of different specialities including infectious disease, rheumatology, and hematology. Ultimately, the decision was made to discharge the patient home on steroids with further outpatient workup. He returned four weeks later with worsening fever and was found to have new-onset mediastinal lymphadenopathy. A biopsy of an inguinal lymph node was obtained which showed high grade-B cell lymphoma. The patient was continued on prednisone and started on chemotherapeutic agents which included vincristine, rituximab and cyclophosphamide. Shortly after starting treatment, the patient and family elected for hospice. This case demonstrates the importance of continuously questioning the diagnosis at hand and of keeping an open mind when evaluating a patient with FUO.

Aortitis as a Harbinger of Esophageal Cancer.

Aortitis is a rare diagnosis that requires a high index of suspicion due to nonspecific symptoms and its multiplicity of etiologies. An 80-year-old man, independent in activities of daily living (ADLs), had three consecutive hospitalizations in three months for fever, general malaise, anorexia associated with arthritis of the hands and feet with the inability to walk. Inflammatory markers were increased without a focus of infection identified. Upper digestive endoscopy (UDE), colonoscopy, blood cultures, thoracoabdominal-pelvic CT and transthoracic (TT) echocardiogram were performed without changes, with discharge for consultation after demonstrating apyrexia. At the patient second hospitalization for fever and arthritis, a transesophageal echocardiogram was performed that showed the presence of multiple complex atherosclerotic plaques, with associated thrombi in all segments of the aorta with a suspicious mass of vegetation on the aorta. Thoracic-abdominopelvic CT demonstrated calcified atheromatosis of the entire aorta with para-aortic nodes; MRI showed aortic thickening; and autoimmunity study was negative. Aortitis was the working diagnosis of possible infectious etiology and anticoagulation and antibiotic therapy were started. Fever recurred and a third admission led to a working diagnosis of inflammatory, non-infectious aortitis. The patient responded well to empiric corticosteroids. The patient followed up in consultation, remained asymptomatic under a low dose of corticosteroids with negative temporal artery biopsy. In the sixth month, he repeated UDE due to dysphagia, which showed the presence of esophageal neoformation with the histological diagnosis of squamous cell carcinoma, maintaining on the CT as alterations in the aorta. This is an unusual case of aortitis associated with arthritis with improvement after corticosteroids, which interestingly occurred before the progression of esophageal cancer. In hindsight, we think this may have been a large vessel paraneoplastic vasculitis that preceded the detection of esophageal squamous cell carcinoma.