Periodic Fever, Aphthous Stomatitis, Pharyngitis, and Cervical Adenitis (PFAPA) Syndrome: a Review of the Pathogenesis

The effect of vitamin D supplementation on attacks in PFAPA syndrome patients with low vitamin D levels

BACKGROUND-AIM

To evaluate the effect of vitamin D supplementation on the frequency and duration of attacks in patients of PFAPA syndrome with low vitamin D levels.

METHODS

This retrospective study comprised PFAPA patients with vitamin D deficiency/insufficiency between 2018 and 2023. The frequency and duration of PFAPA attacks before and after vitamin D supplementation were noted.

RESULTS

Seventy-one patients were included. Of the 71 patients, 24 (33.8%) had vitamin D insufficiency, and 47 (66.2%) had vitamin D deficiency. In patients with vitamin D insufficiency, mean attack frequency and mean attack duration before vitamin D supplementation were 4.3 ± 1.9/year and 2.2 ± 1.6 days, respectively, while mean attack frequency and mean attack duration after vitamin D supplementation were 3.5 ± 2.7/year per year and 1.3 ± 0.9 days respectively (p = 0.2, p = 0.2, respectively). In patients with vitamin D deficiency, mean attack frequency and mean attack duration before vitamin D supplementation were 7.4 ± 2.1/year and 2.2 ± 1.6 days, respectively, while mean attack frequency and mean attack duration after vitamin D supplementation were 3.3 ± 2.4/year and 1.3 ± 0.9 days respectively (p < 0.01, p = 0.04, respectively). When the vitamin D level and the frequency of attacks were compared, the cut-off value of vitamin D was found to be 29.7 nmol/L.

CONCLUSIONS

In PFAPA patients with low vitamin D levels, the frequency and duration of PFAPA attacks were reduced with vitamin D supplementation. Especially at vitamin D level cut-off > 29.7 nmol/L, the frequency of attacks reduced significantly.

Adult-onset Periodic Fever, Aphthous Stomatitis, Pharyngitis and Cervical Adenitis Syndrome Responsive to Colchicine

We herein report a rare case of periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) syndrome that occurred in an 18-year-old man. He visited our hospital with recurrent episodes of a fever, pharyngitis and adenitis without suggestive findings of infection. These episodes resolved within 5 days and recurred quite regularly, with an interval of about 30 days. As the febrile episodes significantly impaired his quality of life, he was treated with colchicine (0.5 mg) as prophylaxis. This completely prevented the episodes during six months of follow-up. Colchicine may therefore be effective in cases of adult-onset PFAPA syndrome.

Repeated Necrotizing Lymphadenitis with MEFV Gene Mutations

We herein report a 36-year-old man with repeated necrotizing lymphadenitis due to MEFV gene mutations. The patient's chief complaints were a fever and painful cervical lymphadenopathy. We diagnosed him with necrotizing lymphadenitis based on the pathological findings of the lymph nodes and the exclusion of other differential diseases. The same episode recurred four times. We speculated the involvement of autoinflammatory backgrounds and detected MEFV gene mutations of E148Q (homo), P369S, and R408Q. Considering the elevation of interleukin-18, these mutations probably played roles in the repeated necrotizing lymphadenitis.

The role of inflammatory mediators in the pathogenesis of periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) syndrome

INTRODUCTION

As a recurrent disease, periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome is characterized by episodes of febrile attacks and is often prominent in children under five years of age. However, the etiology of this condition has not been fully understood yet.

MATERIALS AND METHODS

The search in the extensive literature of peer-reviewed articles published from the inception to December 2021 was conducted to identify the relevant studies, using the electronic databases of MEDLINE/PubMed, Embase, Scopus, the Cochrane Library, and the Web of Science.

RESULTS

The analysis of complex relationships indicates that inflammatory factors, such as various cytokines and acute-phase proteins (APPs), play leading roles in the pathogenesis of this disease. Accordingly, this article summarizes the current state of knowledge to explain the mechanisms involved in inflammatory responses among patients with PFAPA syndrome and investigate its role in the pathogenesis of this disease. Moreover, the possibilities for further implementation of new therapeutic strategies are pointed out.

CONCLUSION

It is concluded that some pathophysiological processes are associated with immune dysregulation, which itself may be secondary to environmental factors, genetic background, and underlying diseases, including latent infections that multiply inflammatory mediators. elevated inflammatory markers similarly play a significant part in the clinical outcomes of this condition, whose pyrogenic nature is the reason for the development of episodes of febrile attacks in the population of patients suffering from PFAPA syndrome.

PFAPA (periodic fever, aphthous stomatitis, pharyngitis, and adenitis) syndrome: an overview of genetic background

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome is an autoinflammatory disorder with an uncertain origin. PFAPA manifestations occur in the form of regular attacks accompanied by a rise in inflammatory markers. Regarding the family clustering of PFAPA and its similarities with other autoinflammatory disorders such as familial Mediterranean fever, a genetic basis is suggested for the disease. Studies have conducted genome analysis in order to find possible gene variants in PFAPA. Associations with variations in several genes such as MEFV, NLRP, TNFRSF1A, CARD15/NOD2, and MVK have been suggested and analyzed. Inflammasomes, intracellular proteins that are members of innate immunity and activate interleukin-1b (IL-1b) and IL-18, are proposed to be involved in PFAPA pathogenesis. The investigations show that a single gene cannot be found in association with PFAPA, and that it might have a multifactorial or polygenic basis, in which an environmental trigger can provoke inflammasome activation and activate PFAPA flares.

PIK3AP1 and SPON2 Genes Are Differentially Methylated in Patients With Periodic Fever, Aphthous Stomatitis, Pharyngitis, and Adenitis (PFAPA) Syndrome

Periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome is the most common autoinflammatory disease in children and is often grouped together with hereditary periodic fever syndromes, although its cause and hereditary nature remain unexplained. We investigated whether differential DNA methylation was present in DNA from peripheral blood mononuclear cells (PBMC) in patients with PFAPA vs. healthy controls. A whole-epigenome analysis (MeDIP and MBD) was performed using pooled DNA libraries enriched for methylated genomic regions and identified candidate genes, two of which were further evaluated with methylation-specific restriction enzymes coupled with qPCR (MSRE-qPCR). The analysis showed that the PIK3AP1 and SPON2 gene regions are differentially methylated in patients with PFAPA. MSRE-qPCR proved to be a quick, reliable, and cost-effective method of confirming results from MeDIP and MBD. Our findings indicate that a B-cell adapter protein (PIK3AP1), as the PI3K binding inhibitor of inflammation, and spondin-2 (SPON2), as a pattern recognition molecule and integrin ligand, could play a role in the etiology of PFAPA. Their role and the impact of changed DNA methylation in PFAPA etiology and autoinflammation need further investigation.

Recurrence of periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome after tonsillectomy: case-based review

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome is a recurrent fever syndrome for which tonsillectomy is a therapeutic option curing the disease in most patients. Recurrence after remission with tonsillectomy is extremely rare. Increasing number of reports on diverse disease manifestations in PFAPA could give us clues about the disease etiopathogenesis. We aimed to describe a patient with recurrence of PFAPA syndrome after tonsillectomy and to review the previous studies including similar cases. We report a 17-year-old boy with PFAPA syndrome who experienced remission for 3 years after tonsillectomy and was later found to harbor an MEFV mutation when the disease relapsed. He responded well to colchicine treatment at relapse. The literature review revealed 14 articles describing 24 similar PFAPA patients. The therapeutic options include single-dose corticosteroids and nonsteroidal anti-inflammatory drugs during attacks, cimetidine, and resurgery. The presented case was the only one heterozygous for an MEFV mutation and treated with colchicine at disease relapse. Albeit rare, the reoccurrence of PFAPA after tonsillectomy could occur. The presence of such patients opposes with the hypothesis that the trigger or immune dysregulation in PFAPA pathogenesis resides in tonsils.

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome: main features and an algorithm for clinical practice

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome is a recurrent fever syndrome of early childhood with increasing number of adult-onset cases. Although it is a self-limited disease, it may negatively affect the quality of life. The aim of this review is to present a detailed analysis of PFAPA syndrome and an algorithm for diagnosis, therapeutic options, and evaluation of outcome. A comprehensive literature search was conducted through the Cochrane Library, Scopus, and MEDLINE/PubMed databases. The main topics covered are the epidemiology, clinical manifestations, diagnosis, differential diagnosis, etiopathogenesis, genetics, management, disease course and prognosis, disease in adults, unsolved issues, and unmet needs in PFAPA. The diagnosis of PFAPA is mainly based on clinical classification criteria. The most relevant hypothesis for pathogenesis is that dysregulated immune system in a genetically predisposed individual responds to a yet unidentified trigger in an exaggerated way. The pedigree analyses suggest a genetic background for the disease with an autosomal dominant pattern of inheritance. For management, single-dose corticosteroids during attacks and tonsillectomy remain the most effective therapies, while colchicine is a promising option to decrease attack frequency. There remain unsolved issues in PFAPA such as the exact etiopathogenesis and genetic background, the reason why the inflammation is restricted to the oropharyngeal lymphoid tissue, reasons for clock-work regularity of attacks, and self-limited disease course. There is need for a valid diagnostic criteria set with a high performance for both children and adults and consensus on management of PFAPA.

Long-Term Outcome of Classic and Incomplete PFAPA (Periodic Fever, Aphthous Stomatitis, Pharyngitis, and Adenitis) Syndrome after Tonsillectomy

OBJECTIVE

To compare the effectiveness of tonsillectomy and the long-term outcome of periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome in patients fulfilling the classic diagnostic criteria and in those with regularly recurring fever as the only symptom or with onset of symptoms after age 5 years or both.

STUDY DESIGN

We reviewed the medical records of 3852 children who underwent tonsillectomy between 1990 and 2007 and identified 108 children who did so because of regularly recurring fevers. The patients were invited to an outpatient visit and were classified into 2 groups: those who met (N = 58) and those who did not meet (N = 50) Thomas diagnostic criteria. We then compared the clinical profile and outcome of PFAPA symptoms after tonsillectomy between the 2 groups.

RESULTS

In the group that met Thomas criteria, 97% (56/58) had complete resolution of fever episodes after tonsillectomy; in the group that did not meet Thomas criteria (50/50) had complete resolution of fever episodes after tonsillectomy (P = .25). The clinical profile of the periodic fevers and the occurrence of other illnesses during follow-up were similar in both groups. Thomas criteria identified 56 of 106 patients responding to tonsillectomy.

CONCLUSIONS

Tonsillectomy was an effective treatment for patients with regularly recurring fever episodes who failed to meet the classic Thomas criteria. We suggest that PFAPA syndrome should be suspected and tonsillectomy considered in children with a late onset of symptoms (>5 years of age) or when fever is the only symptom during the episodes.