What is it?
PFAPA is one of the few medical conditions with a name that appropriately describes the condition. It is a disease of unknown etiology that is characterized by regular episodes of fever, aphthous stomatitis, pharyngitis and cervical adenitis . It is primarily a disease of early childhood (less than 5 years), but an adult-onset version has recently been recognized.
How is it presented?
As its name suggests, the disease presents with periodic episodes of fever, aphthous stomatitis, pharyngitis, and cervical adenitis. Outbreaks usually last around 4-5 days and repeat every 3-6 weeks. The rate of occurrence does not change with the seasons, although some patients skip episodes in the summer. Patients are asymptomatic between attacks.
- The fever is usually high and resistant to antipyretics, but patients appear relatively well.
- Erythematous or exudative pharyngitis is present in more than 90% of patients.
- Cervical adenitis is present in about 75% of patients.
- Half of patients will develop oral aphthous ulcers, which are usually shallow, round ulcers less than 1 cm in size, with well-demarcated erythematous margins, occurring on the non-masticatory surfaces of the mouth.
- Patients may also have other symptoms, such as headache, myalgia, abdominal pain, rash, vomiting, and diarrhea.
How common is it?
It is the most common periodic fever syndrome in children, but is still quite rare with an incidence of approximately 2 per 10,000.
How is it diagnosed? It is a clinical diagnosis. The proposed diagnostic criteria are:
At least one of the following:
There are a few other clues, often listed along with the diagnostic criteria:
There is also an adult -onset variant (over 16 years of age), with slightly different diagnostic criteria:
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What are the differential diagnoses?
Most patients with multiple visits for pharyngitis will only have recurrent infections. PFAPA should occur more regularly , you will not have other symptoms of respiratory infection such as coryza, and it will not affect other family members at the same time.
Cyclic neutropenia also causes recurrent fever and oral ulcers, but should be easily distinguished by the presence of neutropenia in blood tests.
The most difficult conditions to distinguish are monogenic autoimmune disorders , such as familial Mediterranean fever, but from an emergency perspective it is sufficient to recognize that this is more than just recurrent infections and obtain a referral.
What is the cause?
We are not 100% sure. There is a genetic component , with familial clustering and a possible autosomal dominant inheritance pattern. There is no known predilection for particular ethnic groups.
The most likely explanation seems to be a genetically predisposed deregulation of the immune system. The tonsils appear to be involved in the pathogenesis, as febrile episodes usually cease after tonsillectomy.
How should it be treated?
A single dose of corticosteroids , usually prednisone at 1-2 mg/kg, will rapidly resolve PFAPA symptoms in approximately 90% of patients. NSAIDs are also frequently used.
Although these patients frequently receive antibiotics, they are obviously ineffective.
Once the diagnosis has been made, there are some options to prevent recurrence.
Colchicine has been used prophylactically to reduce the number of attacks and cimetidine has also been used, but the evidence is much weaker.
Tonsillectomy may be the most effective treatment option, although there appears to be some controversy over its role, especially considering that the disease usually resolves spontaneously after a few years.
What is the prognosis?
The prognosis is excellent . The syndrome does not induce long-term sequelae and is not associated with comorbidities. It usually resolves spontaneously 3 to 5 years after the onset of symptoms.
