Nasal Colonization by Staphylococci and Severity of Atopic Dermatitis

Skin colonization by Staphylococcus aureus (SA) correlates with increased severity of atopic dermatitis (AD). The role of nasal SA carriage and coagulase-negative staphylococci (CNSs) in AD is unclear.

The aim of this study was to assess the influence of colonization of lesional/nonlesional skin and the anterior nares by SA and CNSs on AD severity in 63 adult patients.

Disease severity was assessed with SCORAD index. The total immunoglobulin E (IgE) concentration was determined using the enzyme-linked immunosorbent assay method. The prevalence and abundance of staphylococci were assessed with the combination of bacterial culture and mass spectrometry.

The prevalence values of SA within the skin (lesional/nonlesional) and anterior nares were 79.4%/61.9% and 69.8%, respectively (vs 5.6% and 13.9%, respectively in controls, P < 0.0001). The carriage of CNSs in all niches was associated with lower mean IgE concentration (1164.66 ± 1010.36 vs 1762.99 ± 1059.15, P < 0.0213; 1166.9 ± 1006.4 vs 2152.7 ± 759.2, P < 0.0063; 1022 ± 1100 vs 1925 ± 880.8, P < 0.0044, respectively). The abundance of SA correlated with the extent of skin lesions and total IgE (ρ = 0.42, P = 0.0007; ρ = 0.488, P < 0.0001; ρ = 0.312, P < 0.2; and ρ = 0.402, P = 0.0007; ρ = 0.403, P < 0.002; ρ = 0.287, P < 0.03, respectively).

Atopic dermatitis severity correlates with both cutaneous and nasal colonization by SA. Staphylococcus aureus seems to promote TH2-type response, whereas CNS probably limits this process. Preventive measures within the anterior nares should be considered for AD patients.