title: Protozoa as a cause of recurrent abdominal pain in children.
abstract: OBJECTIVE
  The aim of this study was to investigate whether protozoa can be identified as a cause of recurrent abdominal pain (RAP), and whether protozoan infections can be recognized by a specific clinical presentation.
  
  
  METHODS
  For 2 years, all patients (ages 4-16 years) fulfilling the Apley criteria of RAP referred to secondary care were prospectively evaluated for protozoa (Giardia lamblia, Dientamoeba fragilis, Blastocystis hominis) and treated if positive. Re-examination followed at least 10 days after treatment. Disappearance of pain with eradication and a pain-free follow-up of at least 6 months were considered to be indicative of a causal relation with RAP. The predictive value of the characteristics of the pain for protozoan infections was calculated.
  
  
  RESULTS
  Of 220 included patients (92 boys, mean age 8.8 years), 215 brought a stool sample; 73 (34%) carried parasites, 10 of whom had 2 parasites, 2 had 3 parasites. Sixty-five patients were treated. Twenty-five (11%) were pain-free after eradication (21 had D fragilis, 8 B hominis, 4 G lamblia), of whom 11 had another infection (2) or constipation (9) as second diagnosis for the pain. Five had recurrence of infection with D fragilis and were again pain-free with eradication. Patients with protozoa as cause of their pain did not show differences with respect to their presentation when compared with patients with an asymptomatic infection and patients without protozoa.
  
  
  CONCLUSIONS
  Protozoa were found as the cause of pain in 6% to 11% of children with RAP. These patients did not show a characteristic presentation when compared with patients with other causes of abdominal pain.
authors.affiliation: *Department of Paediatric Gastroenterology, Juliana Children's Hospital/Haga Teaching Hospital, The Hague †Department of Paediatric Gastroenterology, Willem-Alexander Children's Hospital/Leiden University Medical Centre, Leiden ‡Sophia Children's Hospital/Erasmus Medical Centre, Rotterdam, The Netherlands.
authors.forename: Carolien F M
authors.initials: CF
authors.lastname: Gijsbers
authors.forename: Joachim J
authors.initials: JJ
authors.lastname: Schweizer
authors.forename: Hans A
authors.initials: HA
authors.lastname: Büller
mesh_terms: D015746:Abdominal Pain / Q000453:epidemiology / Q000209:etiology* / Q000503:physiopathology / Q000517:prevention & control; D000293:Adolescent; D000328:Adult; D000981:Antiprotozoal Agents / Q000627:therapeutic use; D016845:Blastocystis hominis / Q000187:drug effects / Q000302:isolation & purification; D015984:Causality; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003248:Constipation / Q000503:physiopathology; D004029:Dientamoeba / Q000187:drug effects / Q000302:isolation & purification; D005260:Female; D005500:Follow-Up Studies; D016829:Giardia lamblia / Q000187:drug effects / Q000302:isolation & purification; D006776:Hospitals, Pediatric; D006801:Humans; D007411:Intestinal Diseases, Parasitic / Q000188:drug therapy / Q000469:parasitology / Q000503:physiopathology*; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D011446:Prospective Studies; D011528:Protozoan Infections / Q000188:drug therapy / Q000469:parasitology / Q000503:physiopathology*; D012017:Referral and Consultation; D055502:Secondary Prevention; D012720:Severity of Illness Index; D055815:Young Adult
chemical_list: D000981:Antiprotozoal Agents