COVID‐19 in a case with Kikuchi‐Fujimoto disease

Key Clinical Message The accurate diagnosis of Kikuchi‐Fujimoto disease can protect children from unnecessary diagnostic procedures and treatments. Also, the co‐occurrence of rare diseases with other diseases can improve or worsen the symptoms of the patients.


| 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-C). The patient did not have any history of autoimmune or infectious disease before symptom onset.
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-defined 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).
The diagnosis of KFD is based on histopathologic examination of an involved lymph node biopsy. 1,4 The most common histologic finding is the presence of areas of necrosis and apoptosis which surrounded by CD68 + histiocytes, CD123 + plasmacytoid dendritic cells, and activated CD8 + T-lymphocytes. 7 Also, the absence of neutrophils and eosinophils is an important characteristic in support of the diagnosis. 5,8 Several studies purposed that KFD may be a clinical presentation of lupus lymphadenitis or associated with infectious mononucleosis-like syndromes such as EBV infection. 2,5,6 Therefore, a complete work-up, including precise clinical examination with an excisional biopsy, is recommended to rule out other serious autoimmune and infectious disease.
The long-term prognosis of KFD is good, and deaths have been seen in a few patients with systemic forms of the disease. 6,8 KFD usually resolves within 1-6 months with a 12.2% recurrence rate in children. 1,6 No specific treatment is known for KFD, and the most common approach is supportive therapy. 2,4 NSAIDs are used to relieve some of the localized signs and symptoms such as fever and tenderness of lymph nodes. In severs forms of the disease, patients maybe benefit from corticosteroid therapy, hydroxychloroquine, or intravenous immunoglobulin. 4,8 To our best knowledge, this is the first reported case of KFD, who was affected by COVID-19. Although the association of KFD and COVID-19 cannot be confirmed in this case, considering some cutaneous manifestations of COVID-19, such condition should not be missed. F I G U R E 2 A core needle biopsy was performed from a cervical lymph node and immunohistochemistry assessment showing the cores of lymphoid tissue with well-defined paracortical necrotic lesions with nuclear debris F I G U R E 3 The initial clinical manifestations of patient include cervical lymphadenopathy and face erythematous plaques improved after getting infected with SARS-CoV-2