[How I explore ... primary cicatricial alopecias].

Area of Science:

• Dermatology and Trichology
• Pathology of Hair Follicle Disorders

Context:

• Primary cicatricial alopecias (PCA) are characterized by irreversible hair follicle destruction.
• Inflammation leads to follicular fibrosis and potential stem cell transdifferentiation.
• Understanding the pathogenesis is crucial for accurate diagnosis and management.

Purpose:

• To elucidate the mechanisms underlying primary cicatricial alopecias.
• To outline the diagnostic approach based on clinico-pathologic correlations.
• To categorize PCAs into distinct subtypes for targeted treatment strategies.

Summary:

• PCA results from inflammatory destruction of hair follicles, leading to fibrotic scarring.
• Multipotent stem cells may be involved via transdifferentiation pathways.
• Classification includes neutrophilic, lymphocytic, and mixed types, encompassing conditions like folliculitis decalvans, frontal fibrosing alopecia, and lichen planopilaris.

Impact:

• Provides a framework for diagnosing and classifying diverse primary cicatricial alopecias.
• Highlights the role of inflammation and fibrosis in irreversible hair loss.
• Facilitates further research into the specific etiologies and therapeutic targets for each PCA subtype.