Key Clinical Message
We present a case of a 6-year-old girl with B. hominis in stools,
who developed Henoch-Schonlein purpura. In cases with abdominal pain and
diarrhea - besides microbiological tests, parasitological stool tests,
should also be performed.
Keywords: Blastocystis hominis, vasculitis, diarrhea
INTRODUCTION
Blastocystis hominis is one of the most commonly described
protozoan parasites in human gastrointestinal tract. It is widespread,
though infections with this microorganism are most often related to stay
in tropical or subtropical areas.1 Most authors consider it a commensal
in the colon since it rarely causes symptoms in immunocompetent
individuals even with massive infestation. Nowadays, B. hominisis described as a pathogenic protozoa only in immunocompromised
patients, in whom, in the event of more severe invasions, it could cause
chronic diarrhea syndrome. 2,3
In the colon, B. hominis exists in a variety of forms - vacuolar,
multivacuolar, granular, and ameboid form in the event of massive
infestation, also occurring in feces, together with the cyst form, which
is invasive. It is considered that an avacuolar form does not exist.2
Henoch-Schonlein purpura (HSP) is a self-limiting, systemic,
non-granulomatous, autoimmune inflammatory complex. Its etiology is
still not fully elucidated, but infectious agents - bacteria, viruses,
parasites, more rarely mediacions, tumour processes, etc., are mainly
reported. It is most common in the age range of 4 to 6 years of age -
90% of cases, with slight predominance of male sex.4 The initiating
agent causes formation of antigen-antibody complexes with IgA. These
complexes are deposited in the small vessel walls and they activate the
complement, which is followed by a cascade of reactions resulting in
vasculitis, which can affect many organs and systems - most commonly the
skin, the gastrointestinal tract, the kidneys and the joints.5
CASE SUMMARY
A 6-year-old girl of Roma origin fell ill 3 days before her admission to
our clinic with fever, repeated vomiting and watery diarrhea. Prior to
hospitalization, she did not take any medications. During the physical
examination, the patient was feverish, pale, with dry skin and mucous
membranes. The child had complains of diffuse abdominal pain, which was
exacerbated upon palpation. Patient’s skin was clean, without rash.
Hyperemic throat. Blood tests were performed with the following results:
leukocytosis (WBC: 16,900/microL); Hb: 13 g/dL; Hct: 42.1%; BUN: 16
mg/dL; Serum creatinine: 0.8 mg/dL; Urinalysis: no hematuria or
proteinuria; ESR: 48 mm/hr; CRP: 6.1 mg/dL; EBV-VCA IgM: Negative;
Anti-HAV IgM: Negative; HbsAg: Negative; Anti-HBc IgG: Negative; fecal
cultures for pathogen bacteria remained negative . Infusions of glucose
and saline solutions and oral rehydration were initiated. Approximately
6 hours after patient’s admission, blood admixtures appeared in her
diarrhea stool. Abdominal pain became more severe. At hour 12, palpable
hemorrhagic rash appeared on patient’s ankles, and later on her lower
legs and gluteal region (Figure 1). Patient’s left ankle became painful
and slightly swollen. A fecal test for Campylobacter spp. antigen
was carried out, which was negative, and the test for intestinal
parasites found cysts and ameboid forms of B. hominis - more than
10 per field. Abdominal ultrasonography found only an insignificant
amount of gas in the intestinal loops.
Consultation with a pediatric rheumatologist was carried out, and
according to the criteria of the American College of Rheumatology,
cutaneous and abdominal form of HSP was diagnosed. Administration of
intravenous infusions continued, methylprednisolone 3x20 mg and
therapeutic doses of metronidazole were added to the therapy. After
three days of treatment, the temperature dropped, the abdominal pain
weakened, the rash began to fade. On day 5, the diarrhea syndrome
resolved completely, and there were no inflammatory changes in blood
counts. No forms of B. hominis were found in the repeated fecal
test.
DISCUSSION
According to the literature accessible to us, this is the second such
case, the first case was reported by Turkish authors in a 30-month-old
boy.6 There is a trend of more and more authors reporting symptomatic
infections with B. hominis in immunocompetent individuals.3 The
most common presentation is gastrointestinal discomfort, diarrheal
diseases, including traveller’s diarrhea.2 Cases like this, however,
demonstrate that this parasite can also cause more serious autoimmune
diseases, one of which is Henoch-Schonlein purpura. This once again
confirms the need to keep good personal and public hygiene, since
infection with B. hominis occurs orally. In all cases with such
symptoms - abdominal pain, diarrhea, vomiting - besides microbiological
tests, parasitological stool tests, sometimes three times at intervals
of several days, should also be
Statement of Ethics The authors wish to thank the patients who
kindly gave consent for their cases to be presented in this report.
Author Contributions VV: primary manuscript author. MP: heavily
involved with manuscript editing. PV: manuscript editor.
Disclosure Statement None declared.