Blastocystis sp. subtype 2 detection during recurrence of gastrointestinal and urticarial symptoms

Parasitol Int. 2010 Sep;59(3):469-71. doi: 10.1016/j.parint.2010.03.009. Epub 2010 Apr 2.


Blastocystis is a common unicellular intestinal parasite in humans. Its clinical relevance is still subject to discussion with numerous conflicting reports on its ability to cause disease. A remarkable genetic heterogeneity among isolates suggests an association between distinct subtypes (STs) and pathogenicity, although a clear correlation between symptoms and subtype is lacking. Here, we report on a clinical case which possibly links Blastocystis sp. ST2 infection with the simultaneous occurrence of gastrointestinal illness and generalized chronic urticaria. Despite repeated chemotherapy with different antimicrobial drugs, both the gastrointestinal and cutaneous disorders reoccurred after short symptom-free intervals. Eradication of the parasite and permanent resolution of the patient's medical condition was finally achieved with the combined application of metronidazole and paromomycin.

Publication types

  • Case Reports

MeSH terms

  • Adult
  • Animals
  • Anti-Infective Agents / therapeutic use
  • Blastocystis / classification
  • Blastocystis / genetics
  • Blastocystis / isolation & purification*
  • Blastocystis / pathogenicity
  • Blastocystis Infections / drug therapy
  • Blastocystis Infections / parasitology*
  • Blastocystis Infections / pathology*
  • Chronic Disease
  • Gastrointestinal Tract / parasitology
  • Gastrointestinal Tract / pathology
  • Humans
  • Intestinal Diseases, Parasitic / drug therapy
  • Intestinal Diseases, Parasitic / parasitology*
  • Intestinal Diseases, Parasitic / pathology
  • Male
  • Metronidazole / therapeutic use
  • Paromomycin / therapeutic use
  • Recurrence
  • Urticaria / drug therapy
  • Urticaria / parasitology*
  • Urticaria / pathology
  • Young Adult


  • Anti-Infective Agents
  • Metronidazole
  • Paromomycin