primary care management of anosmia

Last edited 03/2021 and last reviewed 03/2021

Management (1,2):

  • indications for referral to secondary care include patients with any 'red flag' symptoms or >6 weeks of olfactory dysfunction (1)
    • red-flag symptoms for olfactory dysfunction include (1):
      • unilateral nasal symptoms
      • bleeding
      • crusting/scabbing within the nasal cavity
      • cacosmia (perceived malodorous smell)
      • orbital symptoms (swelling, visual symptoms, or ophthalmoplegia)
      • severe frontal headaches
      • frontal swelling
      • the onset of new neurological/meningitic symptom
    • however if the symptoms coincide with symptoms of COVID-19 infection
      • referral should be made after 3 months to allow spontaneous resolution
    • also where a patient has an atypical presentation or has not responded to initial treatment, this would be an indication for referral to secondary care

Treatment will depend on cause

  • in primary care majority of causes related to a primary nasal pathology (e.g. chronic rhinosinusitis, allergic rhinitis, acute sinusitis)
    • intranasal corticosteroids added to disease-specific treatments are the mainstay of treatment
    • in cases of anosmia persisting for >2 weeks, a trial of intranasal corticosteroids should be instigated
      • can be augmented by a course of more potent steroid drops and nasal saline douching at the clinician's discretion
      • oral corticosteroids may lead to resolution of olfactory disturbance in chronic rhinosinusitis; also some possible improvement degree in post-viral anosmia (although the evidence is less strong in this case)
    • recommendations for management of COVID-19-associated anosmia (1)
      • consider a short course of high-dose oral steroids after 2 weeks for persistent symptoms, following resolution of other symptoms related to COVID-19
    • if anosmia is thought to be idiopathic or post-viral, there have been suggestions of various different dietary supplements
      • include zinc, alpha lipoic acid, vitamin a, and omega
      • evidence for their efficacy is poor and does not support their use
    • further imaging is via secondary care
      • in context of suspected cause e.g. MRI may be undertaken to exclude intracranial pathologies such as anterior cranial fossa tumours or demyelinating conditions
    • if no surgical treatment is required and there has been failure of medical management then referral a dedicated smell clinic for olfactory retraining is indicated

Reference:

  • Deutsch PG et al. Anosmia: an evidence-based approach to diagnosis and management in primary care British Journal of General Practice 2021; 71: 135-138. DOI: https://doi.org/10.3399/bjgp21X715181
  • Boesveldt S et al. Anosmia- A Clinical Review Chem Senses. 2017 Sep; 42(7): 513–523.