Hair Aging Revisited: An Expert Delphi Consensus on Pathogenesis, Clinical Features, and Future Therapies

Area of Science:

• Dermatology and Hair Biology
• Aging Research
• Cellular and Molecular Mechanisms of Aging

Background:

• Hair follicle (HF) aging involves structural and functional decline, impacting hair shaft quality.
• Clinical definitions and management guidelines for hair aging are inconsistent.
• This study aimed to establish a consensus on defining and managing hair aging.

Purpose of the Study:

• To define hair aging based on expert consensus.
• To achieve agreement on diagnostic criteria for age-related hair changes.
• To establish consensus on management strategies for hair aging.

Main Methods:

• Modified Delphi methodology employed with a panel of 24 European dermatologists.
• A structured questionnaire assessed expert opinions on hair aging.
• Consensus defined by specific Likert scale score ranges and interquartile range.

Main Results:

• Consensus reached on 51 out of 65 statements (78.5%).
• Hair aging characterized by pigment loss, HF miniaturization, and reduced hair fiber quality.
• Senescent alopecia defined as diffuse thinning; distinct pathophysiology from androgenetic alopecia proposed (stem cell exhaustion, fibrosis, immunosenescence).
• Lifestyle modification and supportive hair care endorsed; minoxidil the only consensus pharmacologic therapy.

Conclusions:

• Provides expert consensus on hair aging, improving diagnostic accuracy and management.
• Highlights agreement and areas needing further research for age-related hair changes.
• Identifies potential new therapeutic targets for slowing hair follicle aging.