Kikuchi-Fujimoto disease, a rare form of necrotizing lymphadenitis, is an uncommon, benign, self-limiting disorder of obscure etiology. It affects mostly young adults of both genders. Clinically, it presents with fever and lymphadenopathy of a firm to rubbery consistency frequently involving cervical lymph nodes while weight loss, splenomegaly, leucopenia, and elevated erythrocyte sedimentation rate feature in severely affected patients. Cutaneous involvement occurs in about 30%-40% of cases as facial erythema and nonspecific erythematous papules, plaques, acneiform or morbilliform lesions of great histologic heterogeneity. Both Kikuchi-Fujimoto disease and systemic lupus erythematosus share an obscure and complex relationship as systemic lupus erythematosus may occasionally precede, develop subsequently, or sometimes be associated concurrently with Kikuchi-Fujimoto disease. It is often mistaken for non-Hodgkin lymphoma while lupus lymphadenitis, cat-scratch disease, Sweet's syndrome, Still's disease, drug eruptions, infectious mononucleosis, and viral or tubercular lymphadenitis are other common differentials. Fine needle aspiration cytology mostly has features of nonspecific reactive lymphadenitis and immunohistochemistry studies usually show variable features of uncertain diagnostic value. Since its diagnosis is exclusively from histopathology, it needs to be evaluated more carefully; an early lymph node biopsy will obviate the need for unnecessary investigations and therapeutic trials. Its treatment with systemic corticosteroids, hydroxychloroquine, or antimicrobial agents mostly remains empirical. The article reviews clinicoepidemiological, diagnostic, and management aspects of KFD from the perspective of practicing clinicians.

Kikuchi-Fujimoto disease (KFD) is a rare, benign, and self-limited disease, characterized by cervical lymphadenopathy and fever. Herein, we analyzed the differences in its clinical manifestations and risk factors for recurrence between children and adults.

We retrospectively reviewed the medical records of patients diagnosed with KFD at a tertiary referral hospital between 2005 and 2019. Patients were divided into two groups based on their age: children (<19 years) and adults (≥19 years).

During the 14-year study period, 127 patients were diagnosed with KFD. Among these, 34 (26.8%) were children and 93 (73.2%) were adults. The fever duration was longer and the frequency of myalgia was higher in adults than in children; however, no other significant symptomatic differences were noted between the two groups. Lymph node evaluation was mainly performed using ultrasound in children (61.8%) and computed tomography in adults (78.5%). Moreover, the frequency of antibiotic use was higher in children than in adults (76.5% vs 54.8%, P = 0.027). In adults, multivariable logistic regression analysis revealed anti-nuclear antibody (ANA) positivity (titer ≥1:80) as a risk factor for recurrence (odds ratio: 7.813; 95% confidence interval = 1.818-33.333; P = 0.006).

The clinical features of KFD in children and adults were similar; however, the preferred imaging study and frequency of antibiotic use differed significantly between the two groups. Furthermore, in adults, ANA positivity was associated with KFD recurrence. Thus, patients with KFD who present with ANA positivity at diagnosis will benefit from a regular follow-up for monitoring KFD recurrence.

Background: Little information exists regarding the differences in the clinical and laboratory characteristics of Kikuchi-Fujimoto disease (KFD) according to age. Objective: To evaluate the clinical and laboratory characteristics of KFD according to age. Methods: The relevance of sex, age, clinical features, laboratory findings, courses, and follow-up results were retrospectively evaluated in patients diagnosed with KFD at Pusan National University Hospital between 2010 and 2020. Results: Eighty patients (46 children and 34 adults) with a mean age of 21.5 ± 11.8 years (range, 3-49 years) were included in the study. Those aged 10-19 years accounted for the largest number of patients (42.5%). Among children, the male sex ratio was higher, especially for patients aged ≤ 9 years. In adults, the female sex ratio was higher, especially for patients aged 20-29 years. Fever, tenderness in the lymph node, and skin rashes were more common in children, while myalgia and weight loss were more common in adults. In children, the recurrence rate was significantly higher among boys than among girls (15.8 vs. 0.0%, P = 0.001); lower platelet count and higher CRP levels were observed among boys than among girls. EBV and ANA positivity rates were higher in boys than in girls. In adults, the recurrence rate was significantly higher in women than in men (18.2 vs. 0.0%, P = 0.005). ANA positivity rates were higher in women than in men. Conclusion: The clinical features, laboratory findings, and recurrence of KFD may differ depending on age and sex. Clinicians should be aware of this.

Background: Histiocytic necrotizing lymphadenitis, also known as Kikuchi-Fujimoto disease (KFD), is a self-limiting inflammatory disease with low incidence and high misdiagnosis rate in children. Furthermore, cases where the clinical presentation resembles acute appendicitis are very rare. Case Presentation: A 14-year-old boy was misdiagnosed as acute appendicitis and received operative treatment at his early visit. He suffered from abdominal pain, vomiting, diarrhea, fever, and lymphadenitis at the ileocecal junction, which were found by B-ultrasonography examination and surgery. Lymphadenectomy, as well as appendectomy, was performed, and KFD was identified by pathological examination. The patient was transferred to our hospital for further therapy because of recurrent fever and abdominal pain after the appendectomy. His temperature became normal after methylprednisolone was administered, and no recurrence was observed till now during follow-up. Conclusions: Necrotizing lymphadenitis involving mesenteric lymph nodes may cause acute-appendicitis-like symptom; KFD should be a diagnostic consideration for mesenteric lymphadenitis.