Prolonged, recurrent and periodic fever — formative SAQs

SAQ 1 (10 marks)

A 3-year-old girl has had high fever every 5 weeks for the last year. Each episode starts abruptly, lasts 4 days, and is accompanied by a sore throat, mouth ulcers and tender enlarged cervical nodes. Between episodes she is entirely well and growing normally. During a documented attack her CRP is 96 mg/L; two weeks later, when she is well, it is 4 mg/L. ^{[2] [3] [4]}

1. State the most likely diagnosis and the pattern of fever it represents. (2) ^{[1] [2]}
2. Give four clinical features that distinguish this syndrome from the hereditary periodic fevers. (4) ^{[3] [4] [5]}
3. Outline the management, including how to abort an attack and the role of tonsillectomy. (4) ^{[3] [6]}

Model answer — SAQ 1

(1) Diagnosis and pattern (2). The most likely diagnosis is PFAPA syndrome (periodic fever with pharyngitis, aphthous stomatitis and cervical adenitis). It represents periodic fever — the subset of recurrent fever in which attacks recur at predictable, stereotyped (clockwork) intervals, in this case every 5 weeks. The rise of CRP to 96 mg/L during the attack and its fall to 4 mg/L when well is a PFAPA signature. ^{[1] [2] [3]}

(2) Distinguishing features (4). Four discriminating features: onset before 5 years with the classic tetrad of fever, pharyngitis, aphthous stomatitis and cervical adenitis; short attacks of 3 to 6 days (FMF is shorter at 1 to 3 days, TRAPS is far longer at 1 to 3 weeks); clockwork 3-to-8-week intervals; and complete wellness with normal growth and normalising inflammatory markers between attacks, which the hereditary fevers (with serositis, periorbital oedema, vaccination-triggered rash or a 21-day neutropenic cycle) do not share. ^{[3] [4] [5] [8]}

(3) Management (4). Reassure the family that PFAPA resolves spontaneously, typically by adolescence, with no long-term sequelae. Abort each attack with a single oral dose of prednisolone 1 to 2 mg per kg at onset, which ends most attacks within hours, though it may shorten the interval to the next episode. For frequent or disruptive attacks, trial cimetidine prophylaxis. Tonsillectomy is supported by three randomised trials and is reserved for severe, refractory disease after multidisciplinary discussion — not first-line, because the syndrome resolves regardless. ^{[3] [6]}