Optical coherence tomography for the investigation of frontal fibrosing alopecia.

BACKGROUND: Frontal fibrosing alopecia (FFA) is a cicatricial alopecia that affects the frontotemporal hairline, eyebrows and body hair. OCT is a non-invasive imaging technique useful in understanding skin architecture and vascularization.

OBJECTIVE: To describe structural and vascular findings in FFA using OCT.

METHODS: This was a case-control study conducted from the months of December 2016-February 2017. The study was IRB approved and conducted at the University of Miami Hospital outpatient dermatology hair and nail clinic in Miami, FL. Four patients with biopsy proven FFA, and three healthy age and sex-matched controls participated. OCT scans were taken on cicatricial alopecic band, inflammatory hairline, eyebrow, uninvolved scalp, facial papules, glabellar red dots and arm. The same body regions were evaluated in controls.

RESULTS: Patients and controls were women aged 42-66. Results reveal epidermal thickness is increased in the inflammatory hairline (0.13 mm) and decreased in the alopecic band (0.08 mm) compared to controls (0.10 mm). Attenuation coefficient increased the inflammatory hairline and decreased in the alopecic band compared to controls. Vascular flow in the alopecic band is decreased compared to inflammatory scalp and controls in the superficial levels, but increased at deeper levels as compared to controls. Inflammatory tissue is consistently more vascular at all levels (P < 0.01). Vascular flows in each stage are significantly different than one another (P < 0.01).

CONCLUSIONS: Increased vascular flow of the deep plexus in cicatricial stages can be a consequence of superficial tissue ischaemia or fibrosis. It is difficult to establish if the increased flow in the inflammatory stage is due to neovascularization as seen in other ischaemic diseases or is the result of the inflammatory response. OCT may be a useful non-invasive tool in imaging FFA. Not only can the technology assist in monitoring disease activity in a non-invasive manner, but it may elucidate new pathophysiologic findings.