Rhinitis with negative skin tests and absent serum allergen-specific IgE: More evidence for local IgE?

Abstract

The phenomenon of local production of IgE in the nasal mucosa is well documented in subjects with allergic rhinitis who have raised serum specific IgE and positive skin prick tests to clinically relevant allergens. Local IgE has also been detected in high levels in nasal polyps in which Staphylococcus-derived enterotoxins are associated with elevated enterotoxin-specific IgE antibodies and likely act as superantigens, thereby promoting increases in polyclonal IgE. Nonallergic rhinitis in the absence of systemic allergen-specific IgE with/without associated eosinophilia affects approximately 25% of patients who experience symptoms of rhinitis. In a subset of this group of heterogeneous disorders, IgE is detectable within the nasal mucosa and/or nasal secretions, implying that an IgE-mediated allergic response may be localized exclusively to the target organ. Huggins and Brostoff originally demonstrated the presence of specific IgE in nasal secretions of patients with rhinitis with negative skin prick tests. A number of studies since have provided further evidence of local allergic rhinitis in such patients. Rondon et al previously reported elevations in allergen-specific IgE in nasal lavage in a proportion of subjects who responded positively to a nasal allergen challenge in the absence of positive skin tests or elevated allergen-specific IgE. In this issue of the Journal, Rondon et al describe the associated local inflammatory response in 30 such patients. The mean age of onset of local allergic rhinitis in the cohort was 31 years, with a female to male bias of 19:11. Nearly half (14/30) of the patients with local allergic rhinitis had asthma, and 57% (17/30) had conjunctivitis. Symptoms were assessed by using a visual analogue scale and nasal patency by acoustic rhinometry at intervals after nasal provocation with grass pollen extract. Tryptase, eosinophilic cationic protein, and grass pollen–specific IgE were measured in nasal lavage. Intranasal challenge resulted in immediate (15 minutes to 1 hour) responses in all subjects and additional late responses (6-24 hours) in 70% of those tested. The proportion of patients with an isolated immediate response was similar to previous studies by the authors. Although the significance of an absent late