Vyzhga Y

University of Toronto

Publications

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(0 citations, 1 total works)

Research Topics

Inflammasome and immune disorders (1) Streptococcal Infections and Treatments (1) Pediatric health and respiratory diseases (1)

PFAPA Syndrome Publications

Differentiating Periodic Fever, Aphthous Stomatitis, Pharyngitis, Cervical Adenitis (PFAPA) and Syndrome of Undifferentiated Recurrent Fever (SURF): A Comparative Study of Clinical Features, Treatment Response, and Remission.

Vyzhga Y, Goh IY, Garibeh E, Feldman BM, Laxer RM , et al.

The Journal of rheumatology • 2026-May-01

To apply proposed classification criteria for periodic fever, aphthous stomatitis, pharyngitis, cervical adenitis (PFAPA) and syndrome of undifferentiated recurrent fever (SURF) to a heterogeneous cohort of children with recurrent fever syndromes and to evaluate the differences in phenotype, treatment response, and disease outcomes. We conducted a retrospective cohort study of 235 children referred to the Autoinflammatory Clinic at The Hospital for Sick Children between 2016 and 2024. Patients were classified as PFAPA or SURF using validated Eurofever/Paediatric Rheumatology International Trials Organisation (PRINTO) classification criteria for PFAPA and empirical indications for SURF. Clinical features; response to corticosteroids, colchicine, and tonsillectomy; and time to remission were compared. Phenotypic clusters were identified using principal component analysis (PCA); log-rank test and Cox proportional hazards regression were used to assess predictors of remission. Of 235 patients, 155 (66%) met PFAPA criteria and 80 (34%) were classified as SURF. Patients with PFAPA more commonly exhibited classical symptoms (aphthous ulcers, pharyngitis, cervical lymphadenopathy), whereas those with SURF were characterized by gastrointestinal and systemic features (abdominal pain, arthralgia, fatigue). Data-driven clustering identified 2 predominant patterns, underscoring heterogeneity: a classic PFAPA cluster and a gastrointestinal-dominant cluster. Neither corticosteroid nor colchicine response was associated with phenotype or remission. Time to remission was shorter in PFAPA than in SURF (median 4.8 vs 5.7 years; = 0.04). Cox regression confirmed SURF classification was an independent predictor of delayed remission (hazard ratio 0.68; = 0.04). Structured classification distinguishes PFAPA and SURF by phenotype and disease trajectory. Data-driven clustering revealed 3 overlapping phenotypic patterns, supporting a continuum of autoinflammatory expression and emphasizing the need for individualized diagnostic and therapeutic approaches.

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Unravelling the clinical heterogeneity of undefined recurrent fever over time in the European registries on Autoinflammation.

Vyzhga Y, Wittkowski H, Hentgen V, Georgin-Lavialle S, Theodoropoulou A , et al.

Pediatric rheumatology online journal • 2024-May-17

Systemic autoinflammatory disorders (SAIDs) represent a growing spectrum of diseases characterized by dysregulation of the innate immune system. The most common pediatric autoinflammatory fever syndrome, Periodic Fever, Aphthous Stomatitis, Pharyngitis, Adenitis (PFAPA), has well defined clinical diagnostic criteria, but there is a subset of patients who do not meet these criteria and are classified as undefined autoinflammatory diseases (uAID). This project, endorsed by PRES, supported by the EMERGE fellowship program, aimed to analyze the evolution of symptoms in recurrent fevers without molecular diagnosis in the context of undifferentiated AIDs, focusing on PFAPA and syndrome of undifferentiated recurrent fever (SURF), using data from European AID registries. Data of patients with PFAPA, SURF and uSAID were collected from 3 registries including detailed epidemiological, demographic and clinical data, results of the genetic testing and additional laboratory investigations with retrospective application of the modified Marshall and PRINTO/Eurofever classification criteria on the cohort of PFAPA patients and preliminary SURF criteria on uSAID/SURF patients. Clinical presentation of PFAPA is variable and some patients did not fit the conventional PFAPA criteria and exhibit different symptoms. Some patients did not meet the criteria for either PFAPA or SURF, highlighting the heterogeneity within these groups. The study also explored potential overlaps between PFAPA and SURF/uAID, revealing that some patients exhibited symptoms characteristic of both conditions, emphasizing the need for more precise classification criteria. Patients with recurrent fevers without molecular diagnoses represent a clinically heterogeneous group. Improved classification criteria are needed for both PFAPA and SURF/uAID to accurately identify and manage these patients, ultimately improving clinical outcomes.

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