title: Elevated immunoglobulin D levels in children with PFAPA syndrome.
abstract: BACKGROUND
  The periodic fever, aphthous stomatitis, pharyngitis and cervical adenitis (PFAPA) syndrome appears to be more common than generally appreciated and should be differentiated from hereditary periodic fever syndromes, particularly from mevalonate kinase deficiency (MKD).
  
  
  METHODS
  14 unrelated patients (7 males, 7 females) met clinical criteria for both the PFAPA syndrome and MKD. Immunoglobulin D (IgD) levels, mevalonic aciduria and mevalonate kinase (MVK) genotype was determined in all patients.
  
  
  RESULTS
  Children experienced their first febrile episode at the age of 24.5±5.9 months (mean±SD), the clinical diagnosis of PFAPA syndrome was established with delay at 42.7±11.7 months. The duration of febrile episodes was 3.4±0.2 days, the asymptomatic interval between them lasted 5.4±0.9 weeks. Accompanying symptoms included pharyngitis (92.8%), cervical lymphadenitis (85.7%), aphthous stomatitis (21.4%), arthralgia (14.3%) and skin erythema (35.7%). Neither mevalonic aciduria nor MVK gene mutations were found in any of the subjects, however, unexpectedly, increased plasma IgD (322.2±29.2 U/l) levels were detected in all patients.
  
  
  CONCLUSIONS
  Raised IgD levels may represent a non-specific epiphenomenon, which frequently accompanies PFAPA syndrome as well as MKD. Because of the overlapping clinical and laboratory features, genetic testing of the MVK gene is indicated to differentiate these two conditions, if clinical criteria for both are fulfilled.
authors.affiliation: 2nd Department of Pediatrics, Comenius University Medical School, Slovakia. kovacs@dfnsp.sk
authors.forename: Laszlo
authors.initials: L
authors.lastname: Kovacs
authors.forename: Anna
authors.initials: A
authors.lastname: Hlavatá
authors.forename: Marián
authors.initials: M
authors.lastname: Baldovič
authors.forename: Ema
authors.initials: E
authors.lastname: Paulovicova
authors.forename: Tomas
authors.initials: T
authors.lastname: Dallos
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Fehérvízyová
authors.forename: Ludovít
authors.initials: L
authors.lastname: Kadasi
mesh_terms: D018771:Arthralgia / Q000175:diagnosis / Q000276:immunology; D002675:Child, Preschool; D015331:Cohort Studies; D003937:Diagnosis, Differential; D004890:Erythema / Q000175:diagnosis / Q000276:immunology; D005076:Exanthema / Q000175:diagnosis / Q000276:immunology; D005260:Female; D005334:Fever / Q000097:blood / Q000235:genetics / Q000276:immunology*; D005838:Genotype; D006801:Humans; D007072:Immunoglobulin D / Q000097:blood*; D007223:Infant; D008199:Lymphadenitis / Q000175:diagnosis* / Q000276:immunology; D008297:Male; D054078:Mevalonate Kinase Deficiency / Q000175:diagnosis / Q000235:genetics; D008798:Mevalonic Acid / Q000652:urine; D010612:Pharyngitis / Q000175:diagnosis* / Q000276:immunology; D013281:Stomatitis, Aphthous / Q000175:diagnosis* / Q000276:immunology; D013577:Syndrome; D013997:Time Factors
chemical_list: D007072:Immunoglobulin D; D008798:Mevalonic Acid