Family History in Periodic Fever, Aphthous Stomatitis, Pharyngitis, Adenitis (PFAPA) Syndrome

Altered serum antibody levels in children with periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis

Objectives

This study aimed to extend the literature by analyzing immunoglobulin (Ig) A, IgE, IgG, IgG2, IgG3, and IgM antibody levels in periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) patients.

Patients and methods

This study retrospectively analyzed the antibody test results of 20 pediatric patients (10 males, 10 females; mean age: 2.5±1.5 years; range, 0.5 to 5.4 years) with and without flare who were initially evaluated for a number of underlying diseases due to periodic fever/infectious symptoms but then diagnosed with PFAPA between January 2015 and December 2020. Antibody levels were determined by chemiluminescence microparticle immunoassay. The results were retrospectively compared with a group of healthy children after the PFAPA diagnosis was confirmed.

Results

The chemiluminescence microparticle immunoassay revealed 35%, 65%, 20%, 86.6%, and 55% of PFAPA cases with low serum levels of IgA, IgG, IgG2, IgG3, and IgM respectively, while 56.2% had high IgE levels. Moreover, low serum levels of at least two antibody classes or subclasses were reported in 80% of the PFAPA children. While cases with low IgG serum levels were with the highest incidence rates among the low IgG3 PFAPA patient population, both high IgE and low IgM cases were common in the rest of the patients.

Conclusion

Our results suggest an association between PFAPA and low serum antibody levels, particularly of IgG3. Future studies are needed to confirm our conclusion.

The use of ketotifen as long-term anti-inflammatory prophylaxis in children with PFAPA syndrome

Introduction

Periodic fever, aphthous stomatitis, pharyngitis and adenitis syndrome (PFAPA) is the most frequent periodic fever syndrome in children. Its pathogenesis is still unknown, but some disease-modifying factors were observed. Several medications were tested for the long-term prophylaxis of inflammatory flares; however, none are standardly used.

Methods

This prospective clinical trial enrolled 142 children (71 girls, 50%) meeting diagnostic criteria for PFAPA syndrome. We analysed selected clinical characteristics and compared laboratory parameters during the flare and attack-free period (at least two weeks after the attack). Moreover, we assessed the possible therapeutic effect of ketotifen on the duration of attack free-periods and clinical picture.

Results

The mean age of patients was 6.81 ± 3.03 years and the mean age of onset of symptoms was 2.31 ± 2.02 years. No significant differences were observed between genders.We recorded a positive family history for PFAPA in 31.69% of patients. Attacks lasted for 2.8 ± 1.2 days, with intervals between attacks of 4 ± 1 weeks. We administered ketotifen in 111 (77.8%) patients, and a positive effect was observed in 86 (77.5%) of patients. We observed prolonged attack-free intervals in patients treated with ketotifen (14.7 ± 8.9 days in comparison with 4.4 ± 1.9 days before the treatment; p<0.001). The used dose of ketotifen was 0.08 ± 0.01 mg/kg/day. Mild side effects were observed in four patients (restlessness, irritability, agitation and constipation).

Discussion

Our data supports the use of ketotifen for long-term prophylaxis in children with PFAPA syndrome with positive effects on the attenuation of disease activity and the prolongation of attack-free periods. Further well-designed studies should confirm the preliminary data.

What is PFAPA syndrome? Genetic clues about the pathogenesis

PURPOSE OF REVIEW

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome is the most common periodic fever syndrome in childhood. Recent studies report genetic susceptibility variants for PFAPA syndrome and the efficacy of tonsillectomy in a broader cohort of patients with recurrent stereotypical fever. In this review, we highlight the findings of these studies and what they may reveal about the pathogenesis of PFAPA.

RECENT FINDINGS

Newly identified genetic susceptibility loci for PFAPA suggest that it is a complex genetic disorder linked to Behçet's disease and recurrent aphthous ulcers. Patients who have PFAPA with some features of Behçet's disease have been reported. Moreover, the efficacy of tonsillectomy has now been described in patients who do not meet the full diagnostic criteria for PFAPA, although the immunologic profile in the tonsils is different from those with PFAPA. Factors that predict response to tonsillectomy are also reported.

SUMMARY

These findings highlight the heterogeneous phenotypes that may be related to PFAPA due to common genetic susceptibility or response to therapy. These relationships raise questions about how to define PFAPA and highlight the importance of understanding of the genetic architecture of PFAPA and related diseases.

Periodic Fever, Aphthous Stomatitis, Pharyngitis, and Adenitis Syndrome and Syndrome of Unexplained Recurrent Fevers in Children and Adults

Children and adults with autoinflammatory disorders, who often experience recurrent fevers, rashes, cold-induced symptoms, conjunctivitis, lymphadenopathy, recurrent infections, aphthous stomatitis, and abnormal blood cell counts, may present to the allergist/immunologist because the symptoms mimic allergies and disorders of immunity. In recent years, there has been increased recognition of non-monogenic autoinflammatory disorders, including periodic fever, aphthous stomatitis, pharyngitis, and adenitis syndrome and syndrome of undifferentiated recurrent fevers. For many clinical practitioners, the natural history, diagnostic criteria, differential diagnoses, and preferred therapies remain challenging because of the presumed rarity of patients and the evolving field of autoinflammation. Here, we aim to provide a practical framework for the clinical allergist/immunologist to evaluate and treat this patient population.

NLRP3 gene variants and serum NLRP3 levels in periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome

OBJECTIVES

Although most of the autoinfammatory disorders have a confirmed genetic cause, periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome still has an unknown genetic background. However, familial cases of PFAPA syndrome have been reported suggesting a genetic its basis. PFAPA syndrome may also be considered an infammasome disorder as variants in infammasome-associated genes such as CARD8, NLRP3, and MEFV have been reported to contribute to the disease.

METHODS

Polymerase chain reaction (PCR)/Sanger sequencing analysis was performed for the detection of the variations in 71 PFAPA patients and 71 healthy controls. NLRP3 concentrations in serum were measured in 71 PFAPA patients and 71 healthy controls.

RESULTS

No statistically significant differences were observed in the allele or genotype frequencies of the NLRP3 polymorphisms between the controls and patients (P > 0.05). We found no significant differences for NLRP3 serum levels between PFAPA patients and controls (p > 0.05). Mutations in the MEFV gene were detected in 32.5% of our patients (13/40).

CONCLUSIONS

It seems that the synergistic effect of different genes plays a role in the formation of PFAPA syndrome. For this reason, it may be useful to examine the presence of mutations in genes such as NLRP3, MEFV, and CARD8 together while investigating the genetics of PFAPA syndrome. Key points • Familial cases of PFAPA syndrome have been reported suggesting a genetic basis for this syndrome. • Elevated serum or plasma levels of IL-1β, IL-6, and IL-18 have been demonstrated during PFAPA flares in several studies. • It seems that the synergistic effect of different genes plays a role in the formation of PFAPA syndrome.

Synchronous disease onset and flares in siblings with PFAPA

BACKGROUND

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) is a clinical syndrome of unclear etiology. PFAPA has generally been considered a non-hereditary fever syndrome; however, this has been called into question with recent reports of family clustering. Few reports have been published describing siblings with PFAPA. To our knowledge, this is the first report of siblings with near simultaneous onset of disease followed by synchronous disease flares.

CASE PRESENTATION

We describe the case of near simultaneous onset of periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis in siblings followed by synchronous disease flares of clear frequency and nearly identical character. Flares were characterized predominantly by fever, aphthous ulceration, cervical lymphadenitis, and the absence of infection. The fever episodes demonstrated a robust response to glucocorticoids and recurred in the same staggered manner every four weeks, with complete absence of symptoms and normal growth and development between episodes. Nine months after onset, the older sibling, a 5-year-old female, underwent tonsillectomy resulting in dramatic resolution of episodes. At the same time, her 2-year-old sister experienced resolution of her fever episodes, though she did not undergo tonsillectomy herself.

CONCLUSION

This is an unusual case of simultaneous onset PFAPA followed by synchronous disease flares. PFAPA is an uncommon clinical syndrome, and it is rarely diagnosed in siblings. The etiology of PFAPA remains unclear. Though the disease is classically considered sporadic, there is a growing body of evidence to suggest that PFAPA may be heritable.

M, Ziaee V. Colchicine versus cimetidine: the better choice for Periodic fever, aphthous stomatitis, pharyngitis, adenitis (PFAPA) syndrome prophylaxis, and the role of MEFV gene mutations

BACKGROUND

During childhood, the most common periodic fever is periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome. The effective treatment and prevention of febrile attacks improve these patients' and their families' quality of life. However, there is no single strategy or evidence-based guideline to manage this syndrome, and most of them are based on consensus treatment plans.

METHODS

This randomized controlled trial was carried out on 67 PFAPA patients referred to three tertiary centers of pediatric rheumatology. The patients were divided into two groups, including group 1 (n = 36) receiving prednisolone plus colchicine and group 2 (n = 31) receiving prednisolone plus cimetidine. Demographic characteristics and the number of febrile episodes were compared between the two groups before and after the intervention.

RESULTS

In both groups, the number of febrile episodes after the treatment decreased (P ≤ 0.001). Statistical Analysis showed no significant difference between the two groups (P = 0.88). Moreover, 44 patients from both groups were checked for the MEFV gene. There were no statistical differences between MEFV positive and negative subgroups in response to colchicine (P = 1).

CONCLUSION

This study showed that both drug regimens are significantly effective in preventing febrile attacks in PFAPA syndrome, and the presence of a MEFV gene mutation might not be the only significant risk factor for a response to colchicine.

TRIAL REGISTRATION

IRCT, IRCT20191222045847N1. Registered 23 October 2019, https://fa.irct.ir/search/result?query=IRCT20191222045847N1.

PFAPA Syndrome: Clinical, Laboratory and Therapeutic Features in a Single-Centre Cohort

Objective

The aim of this study is to describe a group of Romanian children with periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) syndrome.

Materials

This consisted of 39 children diagnosed with PFAPA syndrome according to Thomas’ criteria (eight patients with an age at diagnosis <1 year and 31 patients with an age at diagnosis >1 year).

Methods

Retrospective analysis of the patients with PFAPA syndrome was focused on clinical features, laboratory findings and therapeutic methods. Comparison between the two groups divided by age at onset was also investigated.

Results

Median age at onset was 1.58 years, and median age at diagnosis was 2.97 years. The mean interval between episodes was 35.5 days and the mean duration per febrile episode was 4.1 days. The median diagnosis delay was 2.42 years. The patients presented pharyngitis (100%), adenitis (94.8%) and aphthous lesions (66.7%). The frequency of febrile attacks was higher in children with an age at diagnosis under 1 year (p = 0.0287). Younger age was associated with the presence of aphthae. The mean value of C-reactive protein (CRP) was 7.9mg/dl and the mean value of leucocytes was 14,839/mm³. In 95% of patients given oral corticosteroids, remission of symptoms was reported within 24 h. In three patients, tonsillectomy was performed with complete remission of the disease.

Conclusion

We present a cohort of children with PFAPA syndrome, with clinical and laboratory features similar to those described in the literature. Febrile attacks had a higher incidence in children with younger age at the onset of the disease. The patients had a favorable response to corticosteroids.

Periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis syndrome in children: a brief literature review

OBJECTIVE

To describe clinical, diagnostic and therapeutic characteristics of the periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) syndrome.

DATA SOURCE

Literature review in the PubMed database by using specific descriptors to identify all articles published in the English language in the last three years; 38 articles were found. After performing selection of titles and abstract analysis, 13 out of the 38 articles were fully read. Relevant studies found in the references of the reviewed articles were also included.

DATA SYNTHESIS

The PFAPA syndrome (Periodic Fever, Aphthous Stomatitis, Pharyngitis and cervical Adenitis) is a medical condition grouped among the periodic fever syndromes. The etiology is uncertain, but possibly multifactorial, and its symptoms are accompanied by recurrent febrile episodes although weight and height development are preserved. It is a self-limiting disease of benign course with remission of two to three years without significant interference in the patient's overall development. Treatment consists of three pillars: interruption of febrile episodes, increase in the interval between episodes, and remission.

CONCLUSIONS

Despite several attempts to establish more sensitive and specific criteria, the diagnosis of PFAPA syndrome is still clinical and reached by exclusion, based on the modified Marshall's criteria. The most common pharmacological options for treatment include prednisolone and betamethasone; colchicine may be used as prophylaxis, and surgical treatment with tonsillectomy can be considered in selected cases.

Síndrome da febre periódica, estomatite aftosa, faringite e adenite em crianças: uma breve revisão de literatura

RESUMO Objetivo: Descrever as características clínicas, diagnósticas e de tratamento da síndrome de febre periódica, estomatite aftosa, faringite e adenite (PFAPA). Fontes de dados: Revisão de literatura na base de dados PubMed, feita por meio de descritores específicos para identificar todos os artigos publicados em língua inglesa nos últimos três anos. Dos 38 artigos encontrados, foram encaminhados para leitura integral 13 publicações após seleção de títulos e análise de abstract. Estudos relevantes encontrados nas referências dos artigos revisados também foram incluídos. Síntese dos dados: A PFAPA é traduzida do inglês periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis. Caracterizada por etiologia ainda incerta e possivelmente multifatorial, seus sintomas são acompanhados por episódios recorrentes de febre associados a um desenvolvimento pôndero-estatural preservado. É uma doença autolimitada de curso benigno, com remissão em dois a três anos, sem interferências significativas no desenvolvimento do paciente pediátrico. O tratamento consiste em três pilares: interrupção da crise febril, aumento do intervalo entre crises e remissão. Conclusões: Apesar de várias tentativas de estabelecer critérios atuais mais sensíveis e específicos, o diagnóstico da síndrome PFAPA ainda é clínico e de exclusão com base nos critérios de Marshall modificados. As opções farmacológicas mais utilizadas para o tratamento são a prednisolona e betametasona; colchicina pode ser utilizada como profilaxia e o tratamento cirúrgico com tonsilectomia pode ser considerado em casos selecionados.

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis syndrome: Clinical characteristics and treatment outcomes - a single center study in Japan

BACKGROUND

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome is an autoinflammatory disease occurring in children. Although PFAPA is the most common periodic fever syndrome found in children, there are only a few studies defining the clinical characteristics and the efficacy of treatment strategies among Japanese children. This study aimed to clarify the demographic characteristics and clinical features of patients with PFAPA syndrome and to evaluate treatment efficacy.

METHODS

We retrospectively reviewed the clinical features of children with PFAPA who visited Saitama Children's Medical Center between January and December 2019. We also evaluated treatment strategies and their efficacy; abortive treatment with corticosteroids, prophylaxis with cimetidine or colchicine, and surgical management with tonsillectomy.

RESULTS

A total of 100 Japanese children (61% male) with PFAPA were included. Median age of onset was 3 years, median duration of fever episodes was 5 days, and median interval between episodes was 4 weeks. The symptoms (frequencies) were pharyngitis (89%), exudate on tonsils (71%), cervical adenitis (50%), and aphthous stomatitis (49%). Approximately 37% of patients took prednisolone for aborting fever attacks, showing a 100% response; 93% were treated with cimetidine, showing an 79.6% response, and 18% were treated with colchicine, showing a 66.7% response. Only one patient underwent tonsillectomy.

CONCLUSIONS

Among Japanese children with PFAPA, 28% of them were ≥5 years with a male predominance. Pharyngitis is the most frequent symptom associated with fever. Cimetidine is suitable for initial therapy because of its safety and efficacy.

Periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome: A review

Periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome is the most common periodic fever condition in children, with most cases appearing by the age of 5. Although PFAPA is generally a self-limited condition, it can have a major impact on a child's quality of life, as well as that of their family. Recent research has continued to shed light on the genetic and immunologic factors that play a role in the pathogenesis of PFAPA. There also exists significant heterogeneity in treatment strategies, and progress has been made to develop evidence-based management strategies and establish a standard of care. This review will outline current knowledge regarding the pathogenesis of PFAPA, as well as treatment strategies and our clinical experience.

Colchicine treatment in children with periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome: A multicenter study in Spain

OBJECTIVE

To evaluate the efficacy of colchicine therapy in pediatric patients with PFAPA syndrome who present with an incomplete response to the standard treatment or with frequent episodes (an interval of less than 14 days between two disease flares).

METHODS

A multicenter cohort study of children diagnosed with PFAPA syndrome and treated with colchicine was performed in three separate hospitals located in Spain. The patients clinical and laboratory data were reviewed by accessing their medical records. Response to colchicine was evaluated after 12 months of treatment for frequency, duration, and intensity of PFAPA episodes.

RESULTS

A total of 13 children were included in our study, 43% of whom were boys. Median age of the colchicine therapy initiation was 6 years (interquartile range (IQR)=3-9.5). Following a 12-month period of colchicine therapy (median dosage of 0.02 mg/kg/day; IQR=0.02-0.03), a significant decrease in the median number of flares (median 8; IQR=7-14 vs 3; IQR=2-4; p=0.005) and the duration of disease episodes (median 4 days; IQR=3.25-5.125 vs 1 day; IQR=1-2; p=0.003) was observed. Furthermore, the highest degree of fever during disease flares was reduced from median 40ºC (IQR=39.5-40) to 38.5ºC (IQR=37.7-38.9) (p=0.002).

CONCLUSION

Colchicine therapy decreased the frequency and intensity of PFAPA. The use of colchicine could be an effective treatment in pediatric patients with PFAPA syndrome who present with frequent or severe relapses.

Familial Periodic Fever, Aphthous Stomatitis, Pharyngitis and Adenitis Syndrome; Is It a Separate Disease?

INTRODUCTION

Periodic Fever, Aphthous Stomatitis, Pharyngitis, Adenitis (PFAPA) is the most common periodic fever syndrome in the pediatric population, yet its pathogenesis is unknown. PFAPA was believed to be sporadic but family clustering has been widely observed.

OBJECTIVE

To identify demographic and clinical differences between patients with PFAPA and a positive family history (FH+) as compared to those with no family history (FH-).

METHODS

In a database comprising demographic and clinical data of 273 pediatric PFAPA patients treated at two tertiary centers in Israel, 31 (14.3%) had FH+. Data from patients with FH+ were compared to data from those with FH-. Furthermore, family members (FMs) of those with FH+ were contacted via telephone for more demographic and clinical details.

RESULTS

The FH+ group as compared to the FH- group had more myalgia (56 vs. 19%, respectively, p = 0.001), headaches (32 vs. 2%, respectively, p = 0.016), and a higher carrier frequency of M694V mutation (54% vs. 25%, respectively, p = 0.05). Colchicine was seen to be a more beneficial treatment for the FH+ group as compared to the FH- group; however, with no statistical significance (p = 0.096). FMs displayed almost identical characteristics to patients in the FH+ group except for greater arthralgia during flares (64 vs. 23%, respectively, p = 0.008), and compared to the FH- group they had more oral aphthae (68 vs. 43%, respectively, p = 0.002), myalgia/arthralgia (64 vs. 19%/16%, respectively, p < 0.0001), and higher rates of FH of Familial Mediterranean fever (FMF) (45 vs.15%, respectively, p = 0.003).

CONCLUSIONS

Our findings suggest that patients with a FH+ likely experience a different subset of disease with higher frequency of family history of FMF, arthralgia, myalgia, and might have a better response to colchicine compared to FH-. Colchicine prophylaxis for PFAPA should be considered in FH+.

Independent risk factors for resolution of periodic fever, aphthous stomatitis, pharyngitis, and adenitis syndrome within 4 years after the disease onset

BACKGROUND/OBJECTIVE

Periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome is a polygenic disease with unknown etiology. In this retrospective cohort study, we aimed to evaluate the risk factors for the resolution of PFAPA syndrome within 4 years after the onset.

METHODS

In total, 466 patients with PFAPA syndrome that are being followed up our department were included into the study. Between May 2020 and September 2020, medical charts of the patients were reviewed retrospectively.

RESULTS

The median age of the patients at the time of the study and at disease onset were 8.6 (2.9-20.5; IQR 6.9-10.6) years and 18 (1-84; IQR 11-31) months. On univariate analysis age at disease onset (p = 0.003), positive family history of PFAPA syndrome (p = 0.04), absence of myalgia (p = 0.04), and absence of headache (p = 0.003) were all associated with the resolution of PFAPA syndrome within 4 years after the onset. Multivariate logistic regression analysis revealed that age at disease onset (OR 1.04, 95% CI 1.01-1.07, p = 0.002), positive family history of PFAPA syndrome (OR 2.69, 95% CI 1.12-6.48, p = 0.02), and absence of headache (OR 0.2, 95% CI 0.05-0.74, p = 0.01) were independent risk factors for the resolution of PFAPA syndrome within 4 years after the onset.

CONCLUSION

We report later age of disease onset, positive family history of PFAPA syndrome, and absence of headache as independent risk factors for resolution of PFAPA syndrome within 4 years after the onset.

KEY POINTS

• Periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome is a multifactorial disease with unknown etiology. • Although, PFAPA syndrome usually resolves within 3-5 years after the disease onset, it can persist for years and even continue into adulthood. With our current knowledge, there is no clue to predict which patients will have a long disease course and which patients will not. • Later age of disease onset, positive family history of PFAPA syndrome and absence of headache as independent risk factors for resolution of PFAPA syndrome within 4 years after the onset.

Lifetime prevalence of recurrent aphthous stomatitis and its related factors in Northern Iranian population: The PERSIAN Guilan Cohort Study

OBJECTIVES

Recurrent aphthous stomatitis (RAS) is one of the most prevalent oral inflammatory ulcerative lesions. The aim of this large population base study was estimated lifetime prevalence of RAS and its related factors among the Northern Iranian population.

MATERIALS AND METHODS

This study was conducted on 10,520 participants aged 35-70 years based on the PERSIAN Guilan Cohort Study (PGCS). Prevalence proportions and multivariate logistic regression models were constructed for lifetime RAS prevalence using the SPSS software. Data on potential correlates of RAS including demographic profiles, lifestyle habits, and self-reported past medical histories were obtained.

RESULTS

The lifetime prevalence of RAS was 8.3%. Multivariate logistic models showed that urbanization (adjusted odds ratio (AOR) = 1.2) and having a history of systemic disease, including rheumatic disease (AOR = 2.1), genital aphthous disease (AOR = 11.7), depression (AOR = 1.3), chronic headaches (AOR = 1.8), diabetes mellitus (AOR = 1.6), and epilepsy (AOR = 2), were independent predictors of RAS. In addition, smokers (AOR = 0.5) and individuals older than 50 years of age (AOR = 0.8) were less likely to have a history of RAS. The lifetime prevalence of RAS among the Northern Iranian population was relatively low.

CONCLUSIONS

It seems that predisposing factors, such as younger age, urbanization, and systemic disease, including rheumatic disease, genital aphthous disease, depression, chronic headaches, diabetes mellitus, epilepsy, and not smoking, could contribute to RAS prevalence.

Autoinflammatory Diseases in Childhood

Autoinflammatory diseases are characterized by recurrent fevers and clinical findings of impaired natural immunity and can involve various organ systems. The concept of autoinflammatory disease emerged after the definition of familial Mediterranean fever and tumor necrosis factor receptor-associated periodic syndrome. This new disease group was considered to differ from the standard concept of autoimmune diseases, which is relatively better known in terms of basic features, such as defects in innate immunity and the absence of antibodies. A better understanding has been achieved regarding the genetic and pathogenetic mechanisms of this relatively new disease group over the past 20 years since they were first diagnosed, which have led to some changes in the concept of autoinflammatory diseases. The recent definition classifies autoinflammatory disease to be a wide range of diseases with different clinical features, mainly accompanied by changes in innate immune and rarely in humoral immunity. The spectrum of autoinflammatory diseases is rapidly expanding owing to recent developments in molecular sciences and genetics. This review article discusses the clinical features, classification criteria, treatment options, and long-term prognosis of periodic fever, aphthous stomatitis, pharyngitis, adenitis syndrome, and other common autoinflammatory diseases in the light of current literature.

Phenotype variability of autoinflammatory disorders in the pediatric patient: A pictorial overview

Disruption of innate immunity leading to systemic inflammation and multi-organ dysfunction is the basilar footprint of autoinflammatory disorders (AIDs), ranging from rare hereditary monogenic diseases to a large number of common chronic inflammatory conditions in which there is a simultaneous participation of multiple genetic components and environmental factors, sometimes combined with autoimmune phenomena and immunodeficiency. Whatever their molecular mechanism, hereditary AIDs are caused by mutations in regulatory molecules or sensors proteins leading to dysregulated production of proinflammatory cytokines or cytokine-inducing transcription factors, fever, elevation of acute phase reactants, and a portfolio of manifold inflammatory signs which might occur in a stereotyped manner, mostly with overactivity or misactivation of different inflammasomes. Symptoms might overlap in the pediatric patient, obscuring the final diagnosis of AIDs and delaying the most appropriate treatment. Actually, the fast-paced evolution of scientific knowledge has led to recognize or reclassify an overgrowing number of multifactorial diseases, which share the basic pathogenetic mechanisms with AIDs. The wide framework of classic hereditary periodic fevers, AIDs with prominent skin involvement, disorders of the ubiquitin-proteasome system, defects of actin cytoskeleton dynamics, and also idiopathic nonhereditary febrile syndromes occurring in children is herein presented. Interleukin-1 dependence of these diseases or involvement of other predominating molecules is also discussed.

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.

Common genetic susceptibility loci link PFAPA syndrome, Behçet's disease, and recurrent aphthous stomatitis

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome is the most common periodic fever syndrome in children. The disease appears to cluster in families, but the pathogenesis is unknown. We queried two European-American cohorts and one Turkish cohort (total n = 231) of individuals with PFAPA for common variants previously associated with two other oropharyngeal ulcerative disorders, Behçet's disease and recurrent aphthous stomatitis. In a metaanalysis, we found that a variant upstream of IL12A (rs17753641) is strongly associated with PFAPA (OR 2.13, P = 6 × 10-9). We demonstrated that monocytes from individuals who are heterozygous or homozygous for this risk allele produce significantly higher levels of IL-12p70 upon IFN-γ and LPS stimulation than those from individuals without the risk allele. We also found that variants near STAT4, IL10, and CCR1-CCR3 were significant susceptibility loci for PFAPA, suggesting that the pathogenesis of PFAPA involves abnormal antigen-presenting cell function and T cell activity and polarization, thereby implicating both innate and adaptive immune responses at the oropharyngeal mucosa. Our results illustrate genetic similarities among recurrent aphthous stomatitis, PFAPA, and Behçet's disease, placing these disorders on a common spectrum, with recurrent aphthous stomatitis on the mild end, Behçet's disease on the severe end, and PFAPA intermediate. We propose naming these disorders Behçet's spectrum disorders to highlight their relationship. HLA alleles may be factors that influence phenotypes along this spectrum as we found new class I and II HLA associations for PFAPA distinct from Behçet's disease and recurrent aphthous stomatitis.

Severe Recurrent Fever Episodes With Clinical Diagnosis of Hemophagocytic Lymphohistiocytosis, Incomplete Kawasaki Disease and Systemic-Onset Juvenile Idiopathic Arthritis: A Case Report and Literature Review

The pathogeneses of recurrent fever are quite complicated when excluding repeated infections. Recurrent fever is a common symptom for autoinflammatory diseases, relapse of Systemic-onset juvenile idiopathic arthritis (SoJIA) and recurrent Kawasaki disease (KD). There are no specific diagnostic laboratory tests for the diseases. Some studies showed that KD was the precursor of hemophagocytic lymphohistiocytosis (HLH). Macrophage activation syndrome (MAS) is another form of HLH in SoJIA. Cytokine disturbances are considered to be involved in the pathogenesis of the diseases. We describe a Chinese female toddler that developed three separate fever episodes with eventual diagnose of SoJIA within about 10 months. The first episode was diagnosed as IKD, immunoglobulin nonresponsive KD, and HLH. The second and third episodes were diagnosed as IKD and SoJIA, respectively. The fever was hard to be relieved by antipyretics, and the peak axillary temperature was above 40°C. For every fever episode, infections were excluded. For the first episode, trends over time of hemoglobin, platelets, fibrinogen, and triglycerides indicated HLH, which was finally diagnosed and treated according to the HLH-2004 protocol. For the second episode 6 months later, after excluding an HLH relapse and infections, IKD was finally diagnosed. Oral aspirin was administered, and the HLH treatment was ceased. The third episode occurred 3 months later, and SoJIA was finally diagnosed. For each episode, except for relative tests, we only tested for cytokines interleukin-1β, interleukin-6, and interferon-γ, due to limited laboratory test availability. These cytokines were elevated during remission and rose much higher in the fever phases. The case showed the difficulty to differentiating the recurrent fever in clinical practice. Surveillance of routine laboratory parameters over time might reveal a trend that indicates possible disease, even when parameter values do not meet diagnostic criteria. Changes in cytokine profiles are promising markers for differentiating recurrent fever diseases in future. An unknown immunological defect for the case may contribute to the recurrent immunological insults, and we are following up the recurrence of fever episode.

Towards better diagnostic criteria for periodic fever, aphthous stomatitis, pharyngitis and adenitis syndrome

AIM

Periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) syndrome is the most common cause of a periodic fever in childhood. The exact pathogenesis and the aetiology of PFAPA are still unknown.

METHODS

We conducted a non-systematic review of published articles about PFAPA syndrome and summarised the evidence for diagnostic criteria and treatment options for PFAPA.

RESULTS

The first proposed diagnostic criteria for PFAPA, in addition to periodic fever, included aphthous stomatitis, pharyngitis or cervical lymphadenitis in children younger than five years at the beginning of the symptoms. C-reactive protein (CRP) levels and leucocyte counts increase in most patients during episodes. Recent research reveals that tonsillectomy provides an immediate and long-lasting cure for PFAPA, even in the absence of classic criteria of aphthous stomatitis, pharyngitis or cervical adenitis and in children older than five years.

CONCLUSION

We suggest that PFAPA can be diagnosed in children with at least five regularly occurring fever episodes without any other explanation, even in the absence of aphthous stomatitis, pharyngitis or cervical lymphadenitis and also in children older than five years.

Haploinsufficiency of A20 and other paediatric inflammatory disorders with mucosal involvement

PURPOSE OF REVIEW

This review aims at summarizing the current knowledge of A20 haploinsufficiency and other paediatric inflammatory disorders with mucosal involvement.

RECENT FINDINGS

A20 haploinsufficiency is a newly described autoinflammatory disease caused by loss-of-function mutations in TNFAIP3 that result in the activation of the nuclear factor (NF)-kB pathway. Patients may present with dominantly inherited, early-onset systemic inflammation and a Behçet-like disease, or a variety of autoinflammatory and autoimmune features. In Behçet disease, recent literature provides insights into genetic susceptibility and emerging treatment options; in addition, the first paediatric classification criteria were published. Recent advances in periodic fever, aphthous stomatitis, pharyngitis and adenitis syndrome (PFAPA) suggest that the disease has a complex underlying genetic mechanism and in some cases is inherited in an autosomal dominant pattern with reduced penetrance phenotype in many family members. Activation of the pyrin inflammasome through the RoA signalling pathway uncovers an interesting molecular connection between hyperimmunoglobulinemia D syndrome and familial Mediterranean fever. The description of new monogenic types of inflammatory bowel disease (IBD) may provide novel insights into disease pathogenesis. Finally, recent studies highlighted the role of gut microorganisms and dysbiosis in IBD.

SUMMARY

Monogenic diseases such as A20 haploinsufficiency may help to advance our understanding of disease pathogenesis and to develop targeted therapies for more common, multifactorial disorders with mucosal inflammation.

Clinical features and new diagnostic criteria for the syndrome of periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis

AIM

The syndrome of periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) is a common inflammatory disease that presents with periodic fever. We aimed to establish more specific diagnostic criteria for PFAPA based on the clinical characteristics of PFAPA patients in our directory.

METHOD

The clinical, laboratory, genetic, and family history details of 257 Japanese PFAPA patients treated at our and other affiliated hospitals between April 2000 and April 2018 were analyzed along with quantitative measurements of the number of CD64 molecules on neutrophils, and the levels of serum inflammatory cytokines. The sensitivity and specificity of the criteria were calculated for several diseases.

RESULTS

Because recurrent fevers were crucial findings, they were defined as the required criterion. Tonsillitis/pharyngitis with white moss were important accompanying signs. Other symptoms associated with febrile episodes were cervical lymphadenitis with tenderness, aphthous stomatitis, sore throat, vomiting, and headache but not cough. A total of 159 (62%) patients had a family history of recurrent fevers, indicating autosomal dominant inheritance. C-reactive protein levels were extremely elevated during febrile attacks but normal in attack-free periods. Serum immunoglobulin D levels were high in 72 of the 199 tested patients. Oral glucocorticoid and cimetidine were extremely effective in all and 51.6% of the patients, respectively. We defined the above as supportive criteria. These criteria were sensitive and specific enough to distinguish PFAPA from other recurrent fever diseases. Raised serum interferon-γ levels and remarkable CD64 expression on neutrophils during flare-ups were recognized, indicating they contributed to diagnosis.

CONCLUSION

Our new criteria are useful for diagnosing PFAPA.

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.

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis syndrome - PFAPA syndrome

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome is a complex autoinflammatory disease with a clinical phenotype characterised by recurrent episodes of fever, systemic inflammation and symptoms and signs depicted in disease acronym. Although PFAPA is the most common autoinflammatory disease among children in many parts of the world, the condition is still an enigma, which include the regular episodes, the prompt responses to corticosteroids, the genetic bases for the familial clustering and therapeutic effects of tonsillectomy. This review explores PFAPA syndrome with the aim of describing the current clinical and scientific understanding of the condition.

Risk factors for periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome: a case-control study

The etiology and pathogenesis of periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome are unclear. We performed a case-control study to evaluate potential environmental or lifestyle factors associated with PFAPA morbidity. We enrolled 119 patients with PFAPA syndrome who had undergone tonsillectomy in Oulu University Hospital between 1987 and 2007. We recruited 230 controls, matched for sex, birth date, and place from the database of the Population Register Center of Finland. All the patients and controls completed a questionnaire regarding exposure to environmental triggers during early childhood. Maternal smoking was more common among PFAPA syndrome patients than controls (23 vs. 14%; P = 0.005). PFAPA patients had lower breastfeeding rates than controls (94 vs. 99%; P = 0.006). No other environmental factors were associated with PFAPA syndrome, except having an aquarium at home (P = 0.007). The patient group also used natural or herbal medicines more often than the controls (P = 0.01).

CONCLUSION

Maternal smoking and lack of breastfeeding, known risk factors for common childhood infections, were more common in patients with PFAPA syndrome than in matched controls. Environmental factors may be important in the pathogenesis of PFAPA syndrome and should be evaluated in future studies. What is Known: • The pathogenesis and genetics of periodic fever, aphthous stomatitis, pharyngitis, and adenitis (PFAPA) syndrome remain unsolved. • PFAPA syndrome has been shown to cluster in families. What is New: • Maternal smoking and lack of breastfeeding are more common in patients with PFAPA syndrome than in the controls. • Environmental risk factors may be important in the pathogenesis of the syndrome.

Neither hereditary periodic fever nor periodic fever, aphthae, pharingitis, adenitis: Undifferentiated periodic fever in a tertiary pediatric center

AIM

To describe the frequency and clinical characteristics of patients with undifferentiated periodic fever (UPF) and to investigate whether a clinical classification of UPF based on the PRINTO-Eurofever score can help predicting the response to treatment and the outcome at follow-up.

METHODS

Clinical and therapeutic information of patients with recurrent fever who presented at a single pediatric rheumatology center from January 2006 through April 2016 were retrospectively collected. Patients with a clinical suspicion of hereditary periodic fever (HPF) syndrome and patients with clinical picture of periodic fever, aphthae, pharingitis, adenitis (PFAPA) who were refractory to tonsillectomy underwent molecular analysis of five HPF-related genes: MEFV (NM_000243.2), MVK (NM_000431.3), TNFRSF1A (NM_001065.3), NLRP3 (NM_001079821.2), NLRP12 (NM_001277126.1). All patients who had a negative genetic result were defined as UPF and further investigated. PRINTO-Eurofever score for clinical diagnosis of HPF was calculated in all cases.

RESULTS

Of the 221 patients evaluated for periodic fever, twelve subjects with a clinical picture of PFAPA who were refractory to tonsillectomy and 22 subjects with a clinical suspicion of HPF underwent genetic analysis. Twenty-three patients (10.4%) resulted negative and were classified as UPF. The median age at presentation of patients with UPF was 9.5 mo (IQR 4-24). Patients with UPF had a higher frequency of aphthae (52.2% vs 0%, P = 0.0026) and musculoskeletal pain (65.2% vs 18.2%, P = 0.0255) than patients with genetic confirmed HPF. Also, patients with UPF had a higher frequency of aphthous stomatitis (52.2% vs 10.7%, P < 0.0001), musculoskeletal pain (65.2% vs 8,0%, P < 0.0001), and abdominal pain (52.2% vs 4.8%, P < 0.0001) and a lower frequency of pharyngitis (56.6% vs 81.3%, P = 0.0127) compared with typical PFAPA in the same cohort. Twenty-one of 23 patients with UPF (91.3%) received steroids, being effective in 16; 13 (56.2%) were given colchicine, which was effective in 6. Symptoms resolution occurred in 2 patients with UPF at last follow-up. Classification according to the PRINTO-Eurofever score did not correlate with treatment response and prognosis.

CONCLUSION

UPF is not a rare diagnosis among patients with periodic fever. Clinical presentation place UPF half way on a clinical spectrum between PFAPA and HPF. The PRINTO-Eurofever score is not useful to predict clinical outcome and treatment response in these patients.

Unique histologic features of tonsils from patients with periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome

The objective of this study is to compare the histology and immune cell composition of tonsils from patients with periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis (PFAPA) syndrome to those from patients with obstructive sleep apnea (OSA). Patients with PFAPA and age-matched controls with OSA who had undergone tonsillectomy at Vanderbilt Children's Hospital were recruited. After informed consent, archival paraffin-embedded, formalin-fixed tonsil tissues were obtained. Sizes of major histologic regions were measured. Cores of germinal centers, crypts, and squamous epithelium were assembled on a tissue microarray for immunohistochemical staining and digital image analysis. Features of tonsils from PFAPA and OSA patients were compared with Wilcoxon signed-rank test. Samples from 16 cases with PFAPA and 16 controls with OSA were evaluated. Tonsils from PFAPA cases had significantly smaller germinal centers (0.18 vs. 0.47 mm², p = 0.001) and wider squamous epithelia (176 vs. 138 μm, p = 0.008) than those of OSA patients. The percentages of B and T lymphocytes and myeloid cells were comparable in germinal centers, crypts, and squamous epithelia from PFAPA and OSA patients. Longer time from the last febrile episode in PFAPA cases was associated with larger germinal center area (Spearman's rho = 0.61, p = 0.02). We found differences in the sizes of germinal centers and squamous epithelia in tonsils of patients with PFAPA and OSA, but the cellular compositions within these areas were comparable. Our results suggest that tonsils from patients with PFAPA change histologically over time with enlarging germinal centers following a febrile episode. Additional studies are needed to understand the pathogenesis of PFAPA.