Male Senescence Phenotypes Include Hair Loss and Hair Gain

Male pattern baldness is a prominent component of senescence phenotypes. Hair loss on the scalp is frequently accompanied by hair gain in the concha. The change in hair follicle fate near sensory apertures, such as the ear, nose, and eye, may be more than a cosmetic concern and represent an age-related adaptation in neurosensory communication. Epidemiologists have proposed that the propensity for age-related diseases is programmed during gestation.

This study aimed to investigate variables related to the maternal-fetal interface to hair loss and hair gain measurements in men, as well as to investigate the relationship between age-related hair loss on the scalp and concurrent hair gain in the concha in men.

This is a cross-sectional observational study conducted in a general dermatology clinic. Because accurate birth data are not available in this study population, three proxy variables (maternal age, birth order, and intersibling gap measured in months) were used to approximate the intrauterine environment on follicle fate. Hamilton Norwood ratings were collected by a dermatologist. Historical recall on height and weight at age 18 was compared with actual height and weight collected at the time of visit.

Significant negative correlations were observed between maternal age and intersibling gap, and hair loss scores. Higher hair loss scores on the Hamilton-Norwood scale correlated directly with hair gain in the conchal bowl.

The gain of whisker-type hair in the conchal bowl, a key sensory aperture, may have clinical applications outside cosmetic concerns. The conchal hair growth scale may have greater inter-rater reliability across disciplines that study aging.