Case Presentation
A 20-year-old Caucasian woman presented with a four-week history of fever, chills, generalized joint pains, photosensitivity, fatigue, and myalgia. She had experienced morning stiffness lasting over an hour and progressive shortness of breath in the last three days. Moreover, she reported recurrent and painless oral ulcers over the past month. In addition, she had no gastrointestinal manifestations such as abdominal pain, rectal bleeding, nausea, vomiting, or changes in bowel habits. There was no history of weight loss, night sweats, specific skin rashes, or symptoms of Raynaud’s phenomenon affecting extremities. The patient denied using tobacco, alcohol, or illegal drugs and had no history of diseases. As a housewife, she had no recent contact with individuals exhibiting similar symptoms, and her family history and travel within the past six months were negative. The patient was up-to-date on all required vaccinations.
Two weeks prior to the current admission, the patient had spent three days in the hospital, where doctors diagnosed her with a fever of unknown origin (FUO) and treated her with metronidazole and cefixime. Despite this, her symptoms did not improve and progressively worsened, leading to the current admission.
Examination
Upon admission, the patient exhibited a body temperature of 39 °C, a heart rate of 75 beats/min, a respiratory rate of 15 breaths/min, a blood pressure of 110/75 mmHg, and an oxygen saturation of 97% while breathing ambient air. Despite appearing acutely ill and weak, she was alert, oriented, and responsive to questions. Physical examination revealed diffuse rubbery, soft, and mobile right cervical and supraclavicular lymphadenopathy (2 cm in diameter) with no signs of inflammation. Abdominal palpation showed no hepatomegaly or splenomegaly, and an oral examination revealed a solitary 2 cm lesion covered by exudates, surrounded by a reddish aura, in the buccal mucosa without signs of blistering. Skin examination showed no typical skin lesions, such as a malar rash, and no evidence of current acute inflammation in joints or genital aphthous ulcer.
Investigations
Complete blood count (CBC) results showed a white blood cell count of 3.1 × 109/L, a haemoglobin level of 9 g/dL, and a platelet count of 320 × 109/L. Serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) were within normal limits. Laboratory analysis revealed an erythrocyte sedimentation rate (ESR) of 74 mm/hour, C-reactive protein (CRP) of 69 mg/L, and lactate dehydrogenase (LDH) of 1324 IU/L (normal values 140-280 IU/L). Blood and urine cultures showed no growth of microorganisms.
Serologies conducted using the HITACHI Roche Cobas C311 chemistry analyzer with enzyme-linked immunosorbent assay (ELISA) revealed negative results for Coombs Wright, 2-mercaptoethanol (2ME), perinuclear anti-neutrophil cytoplasmic antibody (p-ANCA), and cytoplasmic anti-neutrophil cytoplasmic antibody (c-ANCA). Tests for HIV, hepatitis viruses, Epstein-Barr virus (EBV), and cytomegalovirus (CMV) were also negative. Venereal disease research laboratory (VDRL) and fluorescent treponemal antibody absorption (FTA-ABS) tests showed negative results. A Tzanck smear on the oral ulcer for herpes simplex virus (HSV) was negative. Positive antinuclear antibody (ANA) and double-strand DNA antibody (dsDNA) titers were found, along with low levels of C3 and C4 complements. The patient was diagnosed with systemic lupus erythematosus (SLE) based on criteria established by the Systemic Lupus International Collaborating Clinics.
Chest x-ray (CXR) and chest computed tomography (CT) scan revealed bilateral pleural effusion, leading to the placement of bilateral chest tubes. The pleural fluid was transudate. An echocardiogram indicated mild pericardial effusion without endocardial vegetation.
To assess the extent of lymphadenopathy, doctors performed additional investigations. Neck ultrasonography revealed enlarged submandibular and supraclavicular lymph nodes, with the largest measuring 2.5 cm in diameter. An abdominopelvic CT scan showed no evidence of lymphadenopathy but revealed hypodense lesions in the liver’s seventh and sixth segments.
To obtain more information, a lymph node biopsy was performed under ultrasound guidance, showing a preserved structure with follicular hyperplasia and necrotizing lymphadenitis with paracortical coagulative necrosis. Immunohistochemistry analysis indicated the expression of CD68 and CD4, consistent with Kikuchi-Fujimoto disease (KFD). Additionally, a liver core biopsy from a hypodense lesion revealed focal lobular hepatocyte necrosis and inflammation with histiocytic neutrophils.
Management: Systemic Lupus Erythematosus
Subsequently, doctors diagnosed the patient with KFD-associated systemic lupus erythematosus (SLE) with extranodal involvement in the liver. Treatment involved hydroxychloroquine (HCQ) and oral corticosteroids (prednisolone). After five days of hospitalization, the patient’s condition stabilized, and doctors discharged her in good health. Over two months of treatment, the lymphadenopathies gradually reduced until they reached complete resolution. Regular observations for six months showed no recurrence of symptoms.
Kikuchi-Fujimoto disease along with Systemic Lupus Erythematosus
Kikuchi-Fujimoto disease (KFD), also recognized as histiocytic necrotizing lymphadenitis, is an uncommon systemic condition predominantly observed in young Asian women, although cases have been documented globally. While KFD can manifest at any age, it predominantly affects individuals under 40 years old.
Typically, KFD presents with tender, swollen, and subacute necrotizing lymphadenopathy, often accompanied by low-grade fever and fatigue. Additional symptoms may include headache, nausea, vomiting, malaise, weight loss, arthralgia, myalgia, night sweats, rash, and thoracic/abdominal pain. Although rare, KFD can also affect extranodal regions such as the skin, bone marrow, and liver. Histological examination of lymph nodes typically reveals a partially preserved structure with follicular hyperplasia and well-defined zones of necrosis. Laboratory results vary, with some patients exhibiting normal values, while others may present with anaemia, elevated ESR, CRP, serum LDH, aminotransferases, and leukopenia.
Due to its nonspecific symptoms, KFD can be misdiagnosed as other infectious, autoimmune, or malignant diseases. Despite being a self-limited condition, a prompt and accurate diagnosis is crucial to avoid unnecessary aggressive treatments. This study presents a rare case of KFD with concurrent liver involvement and systemic lupus erythematosus (SLE).
