Skin prick reaction and nasal provocation response in diagnosis of nasal allergy to the house dust mite.

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.

Evaluation of threshold criteria for the nasal histamine challenge test in perennial allergic rhinitis.

Nasal reactivity to histamine was determined in patients with perennial allergic rhinitis and in control subjects. A histamine titration method delivered by a metered dose pump was used. Stuffiness, itching, and the number of sneezes were recorded, nasal secretions measured, and nasal airway resistance was recorded by active anterior rhinomanometry. Increased nasal reactivity to histamine was observed among rhinitic patients and inversely correlated with the severity of nasal symptoms. A 3-fold increase of post-saline nasal airway resistance (NAR) best differentiated the nasal responses to histamine in rhinitic patients from those in control subjects. A histamine dose of < or = 2.5 microg provoked a 3-fold increase in NAR, strongly suggesting moderate or severe symptomatic rhinitis in most cases. Nasal provocation techniques might be a useful tool for objectively assessing disease severity and response to treatment in perennial allergic rhinitis.