Detection of Lophomonas blattarum (Order: Hypermastigida) from Iranian Patients with Allergic Rhinitis

Background: Allergic rhinitis (AR) is one of the most common allergic diseases triggered by indoor and outdoor allergens. Certain arthropods, such as mites and cockroaches, contain protozoa like Lophomonas blattarum in their intestines to help with digestion that may have some role in AR. We aimed to determine the frequency of L. blattarum in nasal smears of patients with AR in comparison with healthy controls. 
Methods: In this prospective cross-sectional study (March 2015-March 2016), 36 patients with a clinical presentation of AR (with a positive prick test including mites) and 34 normal controls were included at ear, nose, and throat (ENT) clinic at Imam Reza Hospital of Mashhad, Iran. Nasal secretions were evaluated to examine presence of L. blattarum in the patients and control group by direct method. Diagnosis of L. blattarum was based on microscopic observation both on direct smear and Giemsa stained specimens. 
Results: Patients with AR had a higher frequency of L. blattarum in their nasal smears than the control group (25% vs. 2.9%) (P=0.001). 
Conclusion: We found L. blattarum more frequently in the nasal secretion of AR patients compared with healthy subjects; this protozoon may have some role in this condition. However, the relationship between L. blattarum and AR requires further studies to allow a greater understanding.