Nasal Myiasis Mimicking Allergic Rhinitis : A Report of 14 Adult Cases

Background : Human nasal myiasis, primarily is a rare zoonotic infection caused by Oestrus ovis, with a non-specific clinical presentation that can mimic more common conditions, such as allergic rhinitis. Objective : To report a series of nasal myiasis cases in immunocompetent individuals, emphasizing the clinical and paraclinical features that facilitate differential diagnosis from allergic rhinitis and enable early treatment. Methods : We conducted a retrospective study including cases of nasal myiasis diagnosed and managed at the ENT department of the Military Hospital of Tunis over 18-year period (2007–2025). Demographic, clinical, diagnostic, and therapeutic data were analyzed. Results : The mean patient age was 43.2 years (range: 18–70), with a female predominance (sex ratio 0.4). Six patients (43%) originated from rural areas. All presented with acute-onset rhinological symptoms (intense nasal pruritus, sneezing, obstruction, rhinorrhea, and headaches), initially suggestive of allergic rhinitis and partially responsive to antihistamines. Otalgia was noted in 3 cases (21%). Nasal endoscopy revealed live larvae in 11 patients (79%). Two patients consulted after spontaneous larval expulsion, and one had both expelled and retained larvae. Skin prick tests were negative in all cases. Facial CT scans (performed in 36%) were unremarkable. Parasitological analysis confirmed Oestrus ovis in 10 cases (71%). Treatment involved nasal irrigation with saline and an anthelmintic, along with corticosteroids and antihistamines, leading to symptom resolution within an average of 4 days. Conclusion : Nasal myiasis should be considered in cases of atypical or treatment-resistant rhinitis, even in immunocompetent individuals. Nasal endoscopy is crucial for diagnosis. Awareness of this condition is essential to prevent misdiagnosis and ensure prompt, effective management.