# Adult-Onset Periodic Fever, Aphthous Stomatitis, Pharyngitis, and Cervical Adenitis Syndrome on the Basis of Selective IgA Deficiency

## TL;DR

This paper reports a rare case of an adult with both PFAPA syndrome and selective IgA deficiency, highlighting a possible link between these two conditions.

## Contribution

The paper presents a novel case of adult-onset PFAPA coexisting with selective IgA deficiency.

## Key findings

- The patient exhibited typical PFAPA symptoms along with selective IgA deficiency.
- This case suggests a potential association between SIgAD and autoinflammatory diseases like PFAPA.
- The findings emphasize the need for further investigation into the relationship between these conditions.

## Abstract

Periodic fever, aphthous stomatitis, pharyngitis, and cervical adenitis syndrome (PFAPA) is an autoinflammatory disease that is thought to occur with the contribution of genetic and environmental factors, but its etiology has not been clearly elucidated. It is characterized by recurrent attacks with fever, pharyngitis, oral aphthous lesions, and cervical lymphadenopathy, and an increase in the level of serum acute phase reactants is observed during the attacks. Although PFAPA usually begins in childhood, adult-onset cases are also reported in the literature. In the pathogenesis of PFAPA, an increase in the expression of various inflammatory cytokines, especially interleukin-1β (IL-1β), is observed as a result of the increase in inflammasome activity. Selective IgA deficiency (SIgAD) is the most prevalent primary immunodeficiency. Although most SIgAD cases remain asymptomatic and remain undiagnosed, it is known that the risk of mucosal infection is generally increased in SIgAD cases. In addition, the frequency of autoinflammatory diseases is increased in SIgAD cases compared with the general population. We aim to present a case of adult-onset PFAPA and SIgAD coexistence.