Statistics
Data management and statistical analyses were performed using IBM SPSS
Statistics version 26 for macOS. For comparison of groups the chi-square
test (χ²) was used. The p-value of significance was <0.05.
Results
The follow-up rate of group A was 85% at 15 and 26 years. The follow-up
rate of group B was 78% at 15 years and 70% at 26 years. Nissen et al.
has tested the differences in distribution, to examine whether the group
with incomplete follow-up differed from the group with complete
follow-up of the subjects in group B (7). The only significant
difference (p < 0.05) was found in a higher prevalence of
eczema (17%) amongst the infants with full follow-up compared to the
group with incomplete follow-up (7%) (7).
During the first year of life, 117 infants (6.7%) of the birth cohort
of 1,749 infants had symptoms suggestive of CMPA. Based on strict
elimination/milk-challenge procedures in a hospital setting, the
diagnosis of CMPA was confirmed in 39 infants, giving a 1-year incidence
of 2.2% (95% CI: 1.5-2.9). Of the 39 infants with CMPA, 21 had
IgE-mediated CMPA (positive skin-prick test and/or radioallergosorbent
test (RAST) of class 2 to cow’s milk protein) and 18 non-IgE-mediated
CMPA. Symptoms of CMPA consisted of cutaneous symptoms (64%),
gastrointestinal symptoms (59%) and respiratory symptoms (33%). 36/39
(92%) had more than one symptom (3, 6).
Table 1 presents the total recovery rates of CMPA from 1 to 26 years of
age. There was full follow-up of the subject with persisting CMPA at 15
and 26 years.
At 15 years of age the prevalence of AA and RC was significantly higher
(p = 0.017 and 0.002, respectively) amongst children with IgE-mediated
CMPA compared to children with non-IgE-mediated CMPA. At 26 years of
age, children with IgE-mediated CMPA had a significantly higher
prevalence of AA (p = 0.002) compared to children with non-IgE-mediated
CMPA. There was not observed any significant difference between children
with IgE-mediated CMPA and children with non-IgE-mediated CMPA at either
age regarding AD.
The prevalence of atopic diseases at 15 and 26 years amongst children
diagnosed with CMPA during their first year of life (group A) and
children from the unselected group of infants (group B) are presented in
table 2.
The development of AA, RC and adverse reactions to other foods until 10
years of age has previously been reported in full (1, 6).
Discussion
This study describes the recovery rate of CMPA until 26 years of age and
the prevalence of atopic diseases at 15 and 26 years of age in a birth
cohort from 1985. Furthermore, it highlights the significant
(p<0.05) differences in development of atopic diseases in a
group of children with CMPA compared to a sample of unselected children
from the same birth cohort.