Seasonal changes in human hair growth

Background: The wash test is currently used to assess hair shedding, though it lacks a cut-off point of normality and any evidence of being reliable. The aim of this study is to provide data to fulfil those needs. Methods: The wash test was employed in a standardized way on 31 children aged 3–11 years. Results: The test yielded 10.68 ± 3.91 hairs, a figure which may be considered as ‘normal’ for children of that age. The χ² test granted the validity of the method. The number of shed hairs counted in the washing basin increased with the age of the subjects. Comment: The wash test proved to be reliable and to be a useful tool for monitoring hair shedding. The increasing trend with age may suggest a possible prepubertal onset of androgenetic alopecia.

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“…We did not observe the seasonal variations other authors have found in adults [4, 5, 6]. As far as we know, no data are available for children.…”

Section: Discussionmentioning

confidence: 37%

Assessing Hair Shedding in Children

Rampini

Guarrera²,

Rampini³

et al. 1999

Dermatology

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“…These results confirm the findings of authors who have formerly demonstrated seasonal changes in human hair growth, though this is the first study performed systematically in women: Orentreich [19] reported 3 women in New York who experienced maximum hair loss in November. By studying a group of 14 men during 18 months, Randall and Ebling [20] showed that the proportions of telogen hair and of hair shedding were maximal in September. Courtois et al [21] observed 10 men, with or without alopecia, for a period of between 8 and 14 years, and also demonstrated a maximal proportion of telogen hairs at the end of summer.…”

Section: Discussionmentioning

confidence: 99%

Seasonality of Hair Shedding in Healthy Women Complaining of Hair Loss

2009

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Background: A number of otherwise healthy women with or without clinical alopecia complain of recurrent hair loss, presumably reflecting seasonality in the growth and shedding of hair. Objective: To test the hypothesis that periodicity in hair shedding reflects seasonal changes in human hair growth. Methods: Retrospective case study over a period of 6 years of apparently healthy women with the complaint of hair loss. All underwent biochemical investigations, and trichograms were made. Results: After exclusion of patients with a disease or on drugs known to cause hair loss, 823 women remained. Analysis of trichograms demonstrated annual periodicity in the growth and shedding of hair, manifested by a maximal proportion of telogen hairs in summer. A second peak seems to exist, though it is less pronounced, in spring. The telogen rates were lowest in late winter. Conclusions: These results confirm the findings of former authors who have indicated seasonal changes in human hair growth, though this is the first study performed systematically in a representative number of women.

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“…Other factors affecting hair growth include pregnancy, metabolic and genetic disorders, nutrition and seasonal changes. 9 Table 1 summarizes the published ranges for hair growth rates for different hair types. An average growth rate of 1 cm per month 4 is assumed for head hair.…”

Section: Hair Growthmentioning

confidence: 99%

Hair testing is taking root

Cooper

2011

Ann Clin Biochem

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An increasing number of toxicology laboratories are choosing to expand the services they offer to include hair testing in response to customer demands. Hair provides the toxicologist with many advantages over conventional matrices in that it is easy to collect, is a robust and stable matrix that does not require refrigeration, and most importantly, provides a historical profile of an individual's exposure to drugs or analytes of interest. The establishment of hair as a complementary technique in forensic toxicology is a direct result of the success of the matrix in medicolegal cases and the wide range of applications. However, before introducing hair testing, laboratories must consider what additional requirements they will need that extend beyond simply adapting methodologies already validated for blood or urine. Hair presents many challenges with respect to the lack of available quality control materials, extensive sample handling protocols and low drug concentrations requiring greater instrument sensitivity. Unfortunately, a common pitfall involves over-interpretation of the findings and must be avoided.

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Seasonal changes in human hair growth

Cited by 219 publications

References 17 publications

Assessing Hair Shedding in Children

Assessing Hair Shedding in Children

Seasonality of Hair Shedding in Healthy Women Complaining of Hair Loss

Hair testing is taking root

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