What investigations are recommended for a patient with chronic sinusitis who has not responded to standard treatment?

Guideline-aligned answer with reasoning, red flags and references. Clinically reviewed by Dr Kola Tytler MBBS CertHE MBA MRCGP.

Posted: 14 August 2025Updated: 14 August 2025 Guideline-Aligned (High Confidence) Clinically Reviewed
Dr Kola Tytler MBBS CertHE MBA MRCGPClinical Lead • iatroX

For a patient with chronic sinusitis who has not responded to standard treatment, the following investigations are recommended:

  • Refer to an appropriate specialist (e.g., ear, nose, and throat specialist or immunologist) for further assessment if symptoms persist despite compliance with 3 months of treatment or if symptoms significantly affect quality of life.
  • Diagnostic nasal endoscopy to document signs of inflammation and detect the presence of nasal polyps.
  • Imaging, particularly CT scanning of the sinuses, to confirm the diagnosis, rule out complications, and exclude neoplasia.
  • Allergy testing to identify allergic or immunological causes that may contribute to chronic sinusitis.
  • Tests of immune function to diagnose possible immunoglobulin deficiencies or other immune dysfunctions.
  • Consider testing for cystic fibrosis or ciliary dyskinesia in children with nasal polyps or sinonasal colonisation with Pseudomonas species.

These investigations help clarify the diagnosis, identify underlying causes or complications, and guide further management in patients with refractory chronic sinusitis.

References:

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