Case report
A 16-year-old girl was admitted to the hospital with a 6-month history of left cervical lymphadenopathy. At the beginning of the disease, the lymph nodes were painless with 0.5 cm size, but over time, they became mobile, rubbery, painful and larger (About 2.5 cm) (Figure 1a). Three months after initial of symptoms, she had frequent fevers, night sweats, myalgia, and weight loss. One month later, the patient complained of hair loss and erythematous plaques on the face, limbs and hands (Figure 1b-1c). The patient did not have any history of autoimmune or infectious disease before symptom onset.
Complete blood count showed elevated erythrocyte sedimentation rate (ESR, 98 mm/h), lactate dehydrogenase (LDH, 865 IU/L), C-reactive protein (CRP, 25 mg/dL). On the other hand, White blood count (WBC, 3600/mcL), Red blood count (RBC, 3.3 million/mcL), Hemoglobin (HB, 9 g/dL), and Hematocrit were decreased. Immunoassay for autoimmune disease were 50 IU/mL for Anti-double stranded DNA (Anti-dsDNA) and 1/1000 Titer for Antinuclear Antibody (ANA). Serology test was negative for rheumatoid factor (RF), human immunodeficiency virus (HIV), hepatitis B and C. Blood culture to detect bacteria, fungi or other common germs were also negative.
A core needle biopsy was performed from a 0.7× 0.7 ×0.1 cm cervical lymph node under ultrasound guided. Immunohistochemistry assessment revealed cores of lymphoid tissue with well define paracortical necrotic lesions with nuclear debris. In addition, there was no infiltration of polymorphonuclear (PMN) leukocytes or plasma cells in microscopic examination (Figure 2). The diagnosis of Kikuchi–Fujimoto disease (KFD) was made for the patient.
The patient was initially supposed to be given prednisolone, but due to fever and cough, prednisolone was refused. The patient was re-admitted and after PCR test, she was diagnosed with Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The patient underwent supportive treatment and interestingly after 7 days the cervical lymphadenopathy and skin rashes significantly improved (Figure 3).