RESUMO
BACKGROUND: The allergen skin test is commonly used to ensure the diagnosis of allergic rhinitis even though positive results do not necessarily indicate that rhinitis is of allergic origin. OBJECTIVE: To determine the association between skin prick reactions and nasal provocation responses to Dermatophagoides pteronyssinus (Der p) allergen extract. METHODS: Twenty-six patients with perennial rhinitis and 25 controls underwent skin prick and nasal provocation tests to standardized Der p allergen extract. With the use of allergen extract titration delivered by a metered dose pump, nasal stuffiness, itching, and sneezing were noted, the amount of secretions measured, and nasal airway resistance was recorded by active anterior rhinomanometry. RESULTS: The majority of the patients with rhinitis (20/26), but none of the controls, exhibited strong skin test positivity (4+) to Der p allergen extract. In addition, the majority of the patients with 4+ skin reactions (16/20) had moderate to severe rhinitis. Significantly increased nasal reactivity to the allergen was also observed among those with 4+ skin test positivity. The controls exhibited nasal provocation responses only with significantly higher end-point doses of the allergen extract regardless of the skin test results. CONCLUSION: Only 4+ skin test positivity was closely associated with increased nasal reactivity to Der p allergen among the patients with perennial rhinitis. The nasal provocation technique would be a useful adjunct testing to ensure the diagnosis of nasal allergy to the Der p mite, particularly among those patients with rhinitis with only mild to moderate skin test positivity.
