[The influence of ageing and seasons on infantile eczema - a population-based cohort study of babies aged 4 months and 10 months].
BACKGROUND
This is probably the first report of a population study on infantile eczema performed for 12 months at two ages of 4 months and 10 months on the same infant group.


METHODS
The Fujiidera Health Center services the health needs of 181,994 inhabitants of Habikino and Fujiidera cities. Between September 1990 and August 1991,1775 newborns were called for a health check-up performed twice a months when they reached 4 months of age. This was repeated for a year when the infants reached 10 months of age. A total of 1493 4-month old infants and 1264 10-month old infants were examined. An expert dermatologist joined this and performed a complete skin examination throughout the study. The eczematous skin changes were evaluated at 50 different points on the body and scored using an originally made chart. Scratch marks were also evaluated at each area. Based on the scores computed eczema was diagnosed when the total score crossed a threshold number. Based on this the examiner diagnoses were categorized as follows: Degree 1: no need to visit a doctor, Degree 2: visit to doctor required, Degree 3: treatment required. Gender was not considered. The data was analyzed by an originally made software using DEC-7000 computer.


RESULTS
Of all the 4-month old infants examined 329 (22.0%) were initially diagnosed to have eczema while of all the 10-month old infants examined 268 (21.2%) were initially diagnosed to have eczema. Further, out of the 329 4-month old infants initially diagnosed with eczema, 228 were again examined when they were 10-months old. Of this sample; 123 (9.7%) infants showed continued symptoms of eczema and 165 (13.1%) infants no longer showed signs of eczema. In addition, out of the 976 4-month old infants initially diagnosed without eczema, 145 (11.5%) newly developed eczema at 10 months. Hence the cumulative diagnosis rate of eczema reached 34.3%. Meanwhile the monthly diagnosis number was significantly higher in Feb (OR 1.84, p=0.031) and significantly lower in Aug (OR 0.21, p<0.001) than the expected number calculated from monthly examination number and the annual diagnosis rate at 4 months. This observation was also the case at 10 months (Feb; OR 2.19, p=0.02, Aug; OR 0.36, p=0.015). The degree of eczema was significantly higher (p<0.001, Mann-Whitney's U test) at 4 months than 10 months. When this was seen monthly, degree 3 was most prevalent in February-March, while degree 2 was most prevalent in October-January for the 4-month olds. For the 10-month olds, both the degree 3 and degree 2 were quite low throughout the year and only degree 1 showed a monthly change similar to degree 2 plus degree 3 of the 4-month olds.


CONCLUSIONS
We therefore conclude that eczematous skin manifestations of infantile eczema are easily changeable by age at less than 1 year and are strongly influenced by seasons.
Fukuzumi
Takayuki
T
Department of Dermatology, Osaka Prefectural Habikino Hospital.
Kobayashi
Eijiro
E
Aoki
Toshiyuki
T
Sasai
Yasunori
Y
Kanamori
Shinobu
S
Yamada
Ichiro
I
D000375:Aging / Q000276:immunology* / Q000473:pathology; D015331:Cohort Studies; D003876:Dermatitis, Atopic / Q000175:diagnosis* / Q000209:etiology; D006801:Humans; D007223:Infant; D012621:Seasons; D012867:Skin / Q000473:pathology