Frontal Fibrosing Alopecia: A Review

Abstract

Frontal fibrosing alopecia is a scarring alopecia, the prevalence of which is increasing worldwide since its first description in 1994. The reason for this emerging epidemic may be a higher exposure to an unknown trigger, although its aethiology and pathogenesis still remain enigmatic. Clinical, trichoscopic, sonographic, and histopathologic findings are allowing clinicians to understand more aspects about this type of cicatricial alopecia. Several treatments have been used in frontal fibrosing alopecia, although the 5-alpha reductase inhibitors seem to be the most promising. The aim of this report is to provide a compilation about the published data regarding frontal fibrosing alopecia in a narrative review.

Keywords: bulge; frontal fibrosing alopecia; histopathology; scarring alopecia; treatment; trichoscopy.

Figure 1

Different unknown triggers, such as facial creams/sunscreens, environmental toxins, surgery, or a stressful situation, may lead to FFA in genetically susceptible individuals. Autoimmunity may also contribute to the predisposition, so people with one autoimmune disease are more likely to have another one. Hormonal factors probably play a role in the development of FFA. Discontinuous lines indicate a regular relationship between two elements. JAK: Janus kinase; AhR: aryl hydrocarbon receptor-kynurenine; mTOR: mammalian target of rapamycin; PPAR-γ: peroxisome proliferator-activated receptor γ; DHEA: dehydroepiandrosterone; HF: hair follicle; IFN: interferon; TGF: transforming growth factor; HLA: human leukocyte antigen; CYP: cytochrome. Created with BioRender.com (accessed on 1 March 2021).

Figure 2

(a) Pattern I: linear and uniform hairline recession, without loss of hair density behind the new hairline. (b) Patter II: diffuse alopecia behind the frontal hairline with loss of hair density behind. (c) Pattern III: unaffected primitive frontal hairline followed by an alopecic band, forming the pseudo “fringe sign”. Note the absence of eyebrow alopecia.

Figure 3

(a) Recession of both fronto-temporal hairlines, mimicking male AGA (AGA-like pattern). (b,c) Recession of the whole hairline, from frontal to occipital (ophiasis-like pattern). (d) Oval alopecic patches in the temporal region, sparing a thin band of temporal hairline (cockade-like pattern). (e) Recession of temporal hairline extending upwards to the parietal scalp (upsilon pattern). In this patient, the frontal hairline is also affected, but not the occipital area, and neither is the retroauricular region.

Figure 4

(a) Frontal hairline: perifollicular erythema and hyperkeratosis, follicles with one hair shaft, white patches, and loss of follicular openings. (b) Eyebrows: partial alopecia with red follicular dots.

Figure 5

Algorithm of treatment. * Some patients with FFA may associate AGA; in these cases, adding minoxidil may provide an additional therapeutic benefit. Created with BioRender.com (accessed on 1 March 2021).