This case discusses a 33 year old male patient who presented over the course of one year (2023-2024) with recurrent episodes of high fever (38-39 ⁰C), malaise, myalgia, pharyngitis, and adenitis. On physical examination at each time a notable tonsillar enlargement and erythema, as well as exudate were observed. The diagnosis of adult onset PFAPA was made based on ruling out other conditions and clinical course of his disease.Case reportOriginalFAPA can present in adults — consider it in recurrent pharyngitis with fever Diagnosis is clinical and by exclusion Steroid responsiveness is a strong diagnostic clue Avoid repeated antibiotics; manage as autoinflammatory diseaseAdult PFAPA underrecognized due to rarity and diagnostic overlap Key differentiator: regular periodicity + rapid steroid response No infectious or autoimmune etiology Awareness critical to prevent unnecessary antibiotics and referralsWhile the diagnosis in children is based most often on a set of criteria first proposed by Marshall et al. and later modified by Thomas et al., building on their clinical observations. The latter set of criteria, often referred to as the modified Marshall criteria, they are not applicable to adults as the first criteria requires the patient to be under 5 years old at the first episode. However, this patient presented with all the signs and symptoms of PFAPA (fever ranging 38-39 ⁰C, sore throat, swollen glands, hoarseness, tonsillar exudate, myalgia, and malaise), excluding age of first onset and thus the diagnosis was determined based on ruling out other conditions and clinical basis. It is unclear whether the hematological disorder he presented is related in this case to the presentation of PFAPA and requires further investigation. This patient illustrates the difficulty of diagnosing this syndrome in an adult due to lack of unifying criteria that exist in pediatrics (modified Marshall criteria) and the need for clinicians to stay vigilant and aware of the adult presentation to prevent unnecessary and potentially harmful use of antibiotics.