Although intestinal parasites are a possible cause of skin disorders, there are few case reports concerning the role of Blastocystis hominis in urticaria. To clarify this association, we determined the frequency of B. hominis genetic subtype in urticarial patients by stool culture and polymerase chain reaction (PCR) and evaluated the clinical and parasitological recovery of urticarial patients after treatment with metronidazole. Of 54 urticarial patients (group I), 18 (33.3%) were diagnosed as acute urticaria (group IA) and 36 (66.7%) were diagnosed as chronic (group IB). Thirty-three (61.1%) out of 54 urticarial (group I) patients were Blastocystis positive by stool culture and PCR. Out of these 33 patients, 21 were symptomatic and 12 were asymptomatic. The amoeboid form was found in 20 (95.2%) out of 21 symptomatic Blastocystis urticarial patients assuring their pathogenic potential. Of 50 normal control group (group II), four (8%) Blastocystis isolates were found with no amoeboid form. B. hominis subtype 3 was the only detected genotype in both groups. Of 20 symptomatic Blastocystis urticarial patients, 12 (60%) patients recovered symptomatically and parasitologically after one course of metronidazole. Recovery reached 100% on repeating the treatment for a second course with disappearance of the amoeboid form. It was concluded that acute urticaria of unknown etiology and chronic idiopathic urticaria patients who are resistant to the ordinary regimen of urticaria treatment might be examined for infection with B. hominis, in order to prescribe the proper specific anti-protozoan treatment.

This pilot study suggests that midodrine is not as effective as intravenous albumin in preventing circulatory dysfunction after large-volume paracentesis in patients with cirrhosis and tense ascites, especially with HCC-positive patients.

Despite accumulating evidence indicating that Blastocystis hominis is pathogenic and that cysteine proteases are involved in its pathogenesis, few researches discussed the protease activity of B. hominis genetic subtypes. Therefore, the present study aims to identify the underlying pathogenic role of the proteases of B. hominis subtype 3 at different molecular weights in correlation to gastrointestinal symptoms. Of 65 patients with various clinical presentations referred to our laboratory for stool examination, 26 (40%) were B. hominis positive by stool culture. Of 26 (group I) B. hominis patients, 18 (69.2%) were symptomatic (group IA) and 8(30.8%) were asymptomatic (group IB). Of 25 normal control group (group II), 5 (20%) were B. hominis positive. Subtype 3 was the only genotype recovered by polymerase chain reaction. Of 26 patients in group I, 19 (73.1%) were immunocompetent and 7 (26.9%) were immunocompromised. Protease activities of B. hominis subtype 3 were recognized at 32-kDa (46.2%), 39-kDa (7.7%), 120-kDa (38.5%), 140-kDa (11.5%), and 215-kDa (19.2%) bands in gelatin sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Proteases were recognized in 17 (94.4%) out of 18 symptomatic Blastocystis patients versus 2 (25.0%) out of 8 asymptomatic patients. Proteases at 32 kDa were reported in 61.1% of symptomatic versus 12.5% of asymptomatic patients. It was concluded that proteases of B. hominis genetic subtype 3, particularly those at 32 kDa, could be considered a virulence factor that is responsible for protein degradation and have a possible pathogenic role in host immune evasion.

Blastocystis hominis is a common intestinal parasite, with a prevalence in developing countries of up to 50%. The aim of this study was to investigate the association of this parasite with urticaria by determining the genotypic isotypes in the Egyptian population. In total, 54 patients with urticaria and 50 controls were enrolled in the study. Stool samples were examined and assessed by PCR. The parasite was detected in a significantly higher number (P < 0.001) of the patient group than the control group. There was no significant difference between the patients with acute and those with chronic urticaria (P = 0.2). The amoeboid form was found in 60.6% of Blastocystis-positive patients with urticaria, but in none of the healthy controls. Subtype 3 was the only isolate found in both the patient and control groups. We recommend treatment for Blastocystis-positive patients with urticaria in developing countries. The prevalence is much lower (around 10%) in developed countries, where treatment should only be considered in the absence of other possible causes of urticaria.

Cryptosporidium infection should be considered in children with ALL presenting with prolonged or severe watery diarrhea during chemotherapy, especially those treated with methotrexate and 6-mercaptopurine. Since Cryptosporidium is not routinely tested for in stool examination, a MZN stain is recommended.