Researchers at Dr. U Hair and Skin Clinic in Los Angeles report that an inflammatory, early fibrotic pattern within androgenetic alopecia (AGA)—commonly known as male or female pattern hair loss—may help explain why some patients stop responding to standard treatments. The findings, published in Clinical, Cosmetic and Investigational Dermatology, suggest that advanced or complex cases of hair loss may involve biological factors beyond hormonal imbalance alone.
Many patients pursue standard therapies, including minoxidil, finasteride, and even hair transplantation, yet experience limited or disappointing results. The study highlights a follicle-centered inflammatory and early fibrotic pattern, termed PIILIF, that may operate alongside AGA, even when the scalp appears normal.
“Many hair loss sufferers do all the right things, yet still see poor outcomes,” said Dr. Sanusi Umar, board-certified dermatologist and lead author. “In a meaningful subset of AGA patients, an inflammatory and early fibrotic driver may be operating in parallel. When that biology is missed, results predictably fall short.”
Study Design and Key Findings
The researchers retrospectively analyzed 129 AGA patients from a referral-center cohort. High-magnification imaging guided biopsies of thinning and normal-appearing scalp, linking microscopic inflammation and fibrosis to clinical outcomes.
- PIILIF prevalence: 81% of patients, often in those 44 and older, with advanced hair loss or prior poor response to treatment.
- Misdiagnosis potential: True seborrheic dermatitis was confirmed in only 0.8% of patients, despite common labeling as “dandruff” or “seb derm.”
- Treatment outcomes: Among AGA-PIILIF patients treated with dual strategies targeting hormonal and follicle-centered inflammatory drivers, 67% improved, while only 2% had suboptimal outcomes.
- Dual-pathway approach: Findings support managing hair loss via both hormonal regulation and immune-based control of inflammation and fibrosis when indicated.
The study also links PIILIF to fibrosing alopecia of patterned distribution (FAPD), suggesting it may represent a later stage of AGA-PIILIF. The authors recommend staging AGA-PIILIF based on perifollicular fibrosis to enable earlier intervention.
Implications for Patients and Clinicians
For patients who do not respond to standard treatments, traditional plans focusing solely on DHT suppression and follicle cycling may be insufficient. Dr. Umar emphasizes the importance of early recognition and targeted management of inflammatory and fibrotic processes.
Long-term care strategies focus not only on stimulating hair growth but also on stabilizing the scalp environment. Steroid-sparing, anti-inflammatory approaches—similar to those used in scarring alopecias—may be appropriate in select cases.
The findings also have implications for hair transplantation planning. In advanced, donor-limited, or post-procedure underperforming cases, scalp biology can influence both predictability and durability. Biopsy-informed planning and scalp optimization are recommended when inflammatory-pattern biology is suspected, rather than immediately pursuing additional grafting.
Moving Toward Clinical Practice
The researchers advocate for structured screening pathways to identify inflammatory-pattern AGA earlier, integrating dual-pathway long-term management where indicated. Dr. Umar highlights the Inflammatory AGA Screen (PIILIF Track) as one model clinicians can adopt and refine.
About Dr. Sanusi Umar
Dr. Umar is the founder of Dr. U Hair and Skin Clinic in Manhattan Beach, a board-certified dermatologist, and clinical instructor at UCLA and Harbor-UCLA. He specializes in complex hair loss, scarring alopecias, advanced AGA, keloids, and repair cases.
