- In all patients (newly diagnosed as well as previously diagnosed) with adult-onset rhinitis, occupational rhinitis should be considered.
- A brief assessment of occupational history can improve the diagnosis of occupational rhinitis.
- Nasal provocation test (NPT) can be considered for diagnosis of occupational rhinitis when immunological tests are not available or unreliable and when a definite diagnosis is needed.
Why this matters
- The diagnosis of occupational rhinitis is challenging as the clinical presentation is non-specific and frequent lack of assessment of occupational history.
- NPT, a strong diagnostic tool, has been previously described in guidelines for detection of standardised high-molecular weight (HMW) allergens.
- The current review discusses the use of NPT in non-standardised allergens in the diagnosis of occupational rhinitis.
- Thinking about the possibility of occupational rhinitis is important in every patient with adult-onset rhinitis, including patients who failed to improve in spite of adequate treatment.
- A brief occupational history, including job title, tasks and exposure to vapours, gases, dust, fumes or chemicals can improve the diagnosis of occupational rhinitis.
- Although immunological tests such as specific immunoglobulin E, skin prick tests or basophil activation test are useful to detect sensitisation, there are several drawbacks with these tests.
- NPT may be indicated for the diagnosis of occupational rhinitis when immunological tests are not available or unreliable and when local allergic rhinitis is suspected, or when a definite diagnosis is needed.
- NPT could be performed in a hospital setting or at work, and the delivery of the agent largely depends on its nature.
- Method of exposure for NPT:
- Water-soluble HMW agents—administered as aqueous solutions.
- Low-molecular-weight and water-insoluble agents—exposure depends on the physical state and chemical properties of the agent.
- Assessment of response for NPT:
- Subjective assessments: symptoms such as sneezing, nasal pruritus, rhinorrhoea, nasal obstruction and ocular symptoms can be assessed using Lebel score or visual analogue scale.
- Objective assessments: peak nasal inspiratory flow, acoustic rhinometry, active anterior rhinomanometry and four-phase-rhinomanometry are the commonly used methods for objective assessment of nasal patency.
- NPT is contraindicated in those with previous anaphylactic reaction to the allergen, acute inflammation of the nose or paranasal sinuses, uncontrolled lower airway disease, pregnancy and other severe comorbidities.