CHRONIC URTICARIA: THE ANSWER WAS IN THE STOOL
Efrain Talamantes, MD; Vishal Goyal, MD; Christian Powell, MD;
University of California, Davis Medical Center, Sacramento, CA
LEARNING OBJECTIVES
DISCUSSION
CLINICAL IMAGES
• Patients with chronic urticaria endure extensive testing that is
often unrevealing and symptom relief is only achieved with
toxic medications
• Chronic urticaria is a common debilitating condition that is a difficult
problem for both patient and physician.
• Eradication of a parasite may result in complete resolution of
chronic urticaria in specific patient populations
• No external cause is identified in 80 to 90% of patients with chronic
urticaria.1
• B. hominis is one of the most common organisms to be detected in
stool, identified in 2.6% of samples submitted to state health
departments. More than 70% of positive samples were from
California.2
CASE INFORMATION
HISTORY:
A 47 year old woman, recently immigrated from Mexico,
presented with a one month history of recurrent pruritic rash,
refractory to topical steroids.
• Rash occurred spontaneously at night and resolved by the
early morning
• The uncertain pathogenesis of B. hominis discourages clinicians from
considering it as a cause and defers treatment, as in our case.
Trichrome is a routinely
employed stain in many clinical
microbiology laboratories, and
studies have shown that it is
more sensitive for the detection
of intestinal protozoa, including
B. hominis.
• Denied using new soaps, lotions, detergents, meds and had
no prior history of allergies or asthma
• Symptoms not associated with arthralgias or fevers
PHYSICAL EXAM:
She was afebrile, HR 76, BP 124/76, and in no acute
distress. Skin exam revealed a diffuse, blanchable macular rash
and diffuse joint tenderness without synovitis.
LABORATORY EVALUATION:
• CBC normal, TSH normal
• ESR high at 53, C1 esterase
inhibitor low at 20, C1q immune
complex normal, C3 low at 40,
C4 undetectable
• ANA neg, RF high normal at 23
CCP neg, cANCA & pANCA neg
• Tissue biopsy showed infiltration
of neutrophils and eosinophils,
consistent with urticaria.
• Stool cultures are positive for
Blastocystis hominis. The rest of
her infectious work-up was
unrevealing.
CLINICAL COURSE
• Oral prednisone for 1 week provided mild relief, but shortly
thereafter developed fevers and diarrhea
• She was then hospitalized for further work-up
• Hydroxychloroquine and doxepin were then started, which
provided mild symptomatic relief
• Nitazoxanide was prescribed to eradicate B. hominis infection
with complete resolution symptoms
• Surveillance stool culture was negative
Urticaria, or hives, are pruritic, edematous, erythematous lesions that are
typically round or oval.
2/24/2009
Pruritic Rash
Derm Consult
• B. hominis has also been shown to be more prevalent in patients with
chronic urticaria.4
EVALUATION AND MANAGMENT
• Chronic urticaria is a diagnoses of exclusion. If hx, PE and testing
(CBC w/ diff, ESR, LFTs, UA, TFTs, tests for autoimmunity)
unremarkable or hives persist for >36hrs, lesions should be biopsied
to rule out vasculitis
• When initial work-up is unrevealing, early eradication of B. hominis
should be pursued in patients with chronic urticaria
TIMELINE
1/30/2009
• B. hominis has repeatedly been described as a true pathogen that may
present with irritable bowel syndrome, skin and other extra intestinal
manifestations.3,4,5
Topical
Steroids
Diagnoses:
Chronic
Urticaria
• Expert consensus recommends treatment of B. hominis with a short
course of Metronidazole, Trimethoprim-sulfamethoxazole , or
Nitazoxanide
H1 blocker
REFERENCES
3/14/2009
Hospital
Admission
Oral
Steroids
Stool O&P
+B. homins
3/25/2009
Rheum
Consult
Hydroxychloroquine
Work-up continues
5/1/2009
Allergy
Consult
Nitazoxanide
Resolution of Sxs
1. Sheikh J, et al: Autoantibodies to the high-affinity IgE receptor in chronic urticaria: how important are they? Curr Opin
Allergy Clin Immunol 2005 Oct;5(5):403-7.
2. Kappus KD, Lundgren Jr RG, Juranek DD, et al: Intestinal parasitism in the United States: Update on a continuing problem.
Am J Trop Med Hyg 1994; 50:705.
3. Kevin S. W. Tan, et al: New Insights on Classification, Identification, and Clinical Relevance of Blastocystis spp. Clinical
Microbiology Reviews 2008, p. 639–665.
4. Funda DOGRUMAN AL, Esra ADISEN, Semra KUST)MUR, Mehmet Ali GÜRER, et al: The Role of Protozoan Parasites
in Etiology of Urticaria. Türkiye Parazitoloji Dergisi 2009; 33 (2): 136 – 139.
5. Yakoob J; Jafri W; Jafri N; Khan R; Islam M; Beg MA; Zaman V, et al: Irritable bowel syndrome: in search of an etiology:
role of Blastocystis hominis. Am J Trop Med Hyg 2004 Apr;70(4):383-5.
6. Pasricha JS, Pasricha A, Prakash OM. Role of gastro-intestinal parasites in urticaria. Ann Allergy 1972; 30: 348–51.