Association between antibiotic exposure within 6 months of age
and AD phenotypes
We define 4 different phenotypes of AD(19): the early-transient
phenotype (n = 111; 14.8%), the early-persistent phenotype (n = 199;
26.5%), the late phenotype (n = 70; 14.8%), and the never/infrequent
phenotype (n = 370; 49.3%).
Antibiotic exposure within 6 months of life was associated with
early-persistent AD compared with non-AD (Table 2; aOR=1.84, 95% CI
1.18–2.86), and the odds increased with a greater number of antibiotic
treatment courses (once: aOR=1.51, 95% CI 0.90–2.55; ≥2 times:
aOR=2.50, 95% CI 1.35–4.63; p=0.049). There was no relationship
between antibiotic exposure and phenotypes other than early-persistent
AD.