Cross‐Sectional Analysis of Subclinical Findings Using High‐Frequency Ultrasound in Frontal Fibrosing Alopecia

OBJECTIVES: Frontal fibrosing alopecia (FFA) has a progressive course; quantifying changes at each visit can be complex. High-frequency ultrasound (HFUS) has been used to assess hair follicle morphology and scalp vascularization. The objectives of the study are to evaluate HFUS characteristics of patients with FFA and, secondarily, to study the usefulness of HFUS in assessing disease activity. METHODS: Prospective study between January and June 2018. Patients with confirmed FFA were included. A retrospective analysis of HFUS imaging and its correlation with clinical presentation was performed. RESULTS: Fifteen AFF female patients (median age: 65 years) met the study criteria. A total of 75 ultrasound images were analyzed. The atrophic region exhibited significant dermis thinning (0.7 mm; 0.3-1.2 mm range) compared to healthy sites. Frontal hair growth area showed reduced follicle number and miniaturization. HFUS Doppler ultrasound identified subclinical inflammation in 26.6% of patients. CONCLUSIONS: HFUS allows the characterization of FFA by quantitatively assessing dermal atrophy and the miniaturization and shrinkage of hair follicles. In addition, it allows the diagnosis of subclinical inflammation.