There is a clear association between atopic dermatitis and skin colonization with S. aureus. Some evidence suggests an increased rate of nasal colonization with S. aureus in patients with allergic rhinitis, but results are inconsistent. We hypothesized that nasal colonization with S. aureus would be associated with allergic rhinitis.
We conducted a cross-sectional study of 61 children with allergist-diagnosed chronic rhinitis, ages 4-17 years old, who were recruited from the Columbia Pediatric Allergy Clinic. Skin prick testing or serum specific IgE testing identified 51 patients with environmental sensitization and ten subjects without sensitization. Anterior nasal swabs were collected to detect S. aureus using chromagar plates and latex agglutination. Methicillin and mupirocin resistance were assessed using cefoxitin disks and E-test strips, respectively. Subjects were screened for atopic comorbidities including asthma, atopic dermatitis and food allergy. Chi square, and when appropriate, Fisher’s exact tests, were used to test for differences in frequencies between groups.
Sensitized subjects (n=51) showed significantly greater S. aureus carriage rates (P=0.01) of 63% (n=32) compared to 20% (2 of 10) of participants without evidence of sensitization. There was no association between the presence of atopic comorbidities and nasal colonization (P>0.05). Ninety-three percent of S. aureus samples were methicillin-sensitive and 100% were mupirocin-sensitive (MIC 0.25).
There was an association between nasal colonization with S. aureus, independent of other atopic comorbidities. Longitudinal studies are needed to assess if sensitization precedes colonization or if nasal colonization with S. aureus predisposes to sensitization.