Linked Article: Olsen et al. Br J Dermatol 2021; 185:1221–1231.

Frontal fibrosing alopecia (FFA) is one of the most common causes of permanent or scarring hair loss. This distressing condition may affect both sexes and all races, although it is most common in post-menopausal white women. The cause of this hair loss condition is unknown, although there may be a genetic susceptibility and hormonal factors may be important. The associated inflammation in the scalp occurs at the level of where the hair follicle stem cells reside, leading to permanent loss of the follicle and the hair shaft that it produces. Classically there is slowly progressive hair loss affecting the front of the scalp and the temples often with redness and scaling around the follicle openings. Some patients notice itching or burning at the involved sites. Eyebrow hair loss occurs in almost 90% of individuals and can precede the scalp hair loss. To date, treatment is usually with antinflammatory topical and systemic agents and anti-androgens but clinical trials assessing the effectiveness of each treatment are currently lacking.

In this paper, an international team of experts in hair disorders from 21 countries sought to obtain a consensus agreement on the criteria for diagnosing and assessing the severity of FFA. Each recommendation needed at least 90% agreement from authors for acceptance. A point scoring method that includes clinical features as well as features seen on biopsy (where a small section of tissue is removed for testing) allows for two categories of FFA – those with the typical hairline recession and those who may present with some of the alternate findings first. Other clinical features that are frequently seen with FFA are tiny yellowish or skin-coloured bumps (papules) on the face and prominent veins on the forehead and they are included in a staging recommendation that captures all of the main clinical features. The authors also propose a method of assessing the degree of hair loss or regrowth after treatment through measuring hair density across the affected scalp before and at set timepoints in follow-up after treatment. Recommendations for a quality of life tool to assess patient response to treatment is also noted.

The authors hope these guidelines will allow the collection of accurate and reproducible clinical and laboratory data, providing the means to both determine the cause of FFA, and to assess the safety and effectiveness of treatment.