CYCLE OF THE SCALP HAIR OF THE NEW-BORN CHILD

[摘要] From the table or the graph, the following conclusions are drawn: From our data it can be seen that the scalp hair of the newborn child may be in any phase of its cycle. In the same region, hairs in different phases of the cycle frequently coexist. The phase of the growth cycle of hair of different regions in an infant can differ. For example, a case was found in which all the hairs in the frontal region were in telogenic phase, in the parietal region they were in the catagenic phase, and in the occipital region most were in the anagenic phase. In any given region there is generally a predominant phase of the cycle. In most regions studied the anagen predominated. The telogen is most abundant in the frontal region and least abundant in the occipital region. The catagen occurs most frequently in the parietal region, and least frequently in the frontal region. The catagen is more frequently found in new-born children than in adults. The relative abundance of hairs in the catagenic phase lead one to conclude that many hairs are synchronously passing through this stage of the cycle. The data included in the table and graph, including the 2 cases of 100% catagen on the parietal scalp and approximately 100% telogen on the frontal scalp indicate that there is a growth wave existing on the scalp of the human at the time of birth. It is clear in these cases that all hairs are in the same cycle and that the growth wave is traversing from front to back over the scalp, similar to that in some animals. Since there were catagen and telogen hairs at birth, anagen in the embryo must be of less than 9 months, and probably only a few weeks duration. Correlation of our data with hair color leads to the conclusion that children, male or female, who at birth have long abundant black hair or of dark heu, have a relatively narrow fore-head and have all their scalp hair in the anagenic phase. In newborns with fair hair, scalp hair is thinner and shorter, the forehead is bare, and the scalp hair is in different stages with a preponderance of the telogen in the frontal region, anagen or catagen in the parietal, and anagen in the occipital region. Mean thickness (largest diameter) of hairs of dark complexioned newborn children was 0.037 mm, while the thickness of hairs of those of light complexion was 0.022 mm. Measurements were made with a regular microscope fitted with a micrometric ocular.