Hypopigmentation of the Eyebrows in Frontal Fibrosing Alopecia

Dear Editor,

Since the initial description of frontal fibrosing alopecia (FFA), a number of features have been incorporated to its clinical picture. Color changes such as cutaneous hypopigmentation of the alopecic band and hyperpigmentation secondary to lichen planus pigmentosus (LPPigm) are examples that the disease transcends the hair follicle [1, 2]. In this manuscript, we describe 22 patients with FFA presenting with marked hypopigmentation of the eyebrows.

Twenty patients were women (18 postmenopausal and 2 premenopausal) and 2 men (age range 34–79 years, median age 59). All patients had skin type IV or higher and presented with bilateral hypopigmentation of the eyebrow area (Fig. 1a), which could be better appreciated on examination with a Wood’s lamp (Fig. 1b). Partial or complete loss of the eyebrows was seen in all cases. Hypopigmentation along the hairline was also noted in 18 (82%) patients (Fig. 2a). LPPigm was present in twenty cases with the diffuse pattern being the most frequent (19) followed by the reticulated pattern (1). Facial papules were observed in 13 (59%) cases.

Hypopigmentation of the hairline has been previously described in FFA patients. Lin et al. [1] reported that FFA epidermal melanocyte counts were found to be lower than the counts seen in biopsy specimens from patients with lichen planopilaris and controls. We speculate that same mechanism could be responsible for the hypopigmentation of the eyebrow area observed clinically. An interesting observation is the sparing of this particular region in patients with LPPigm. This same phenomenon was also observed in the hairline (Fig. 2a, b). LPPigm is characterized by interface dermatitis with pigment incontinence and melanophages in the dermis which results in clinical hyperpigmentation [3]. It could be that for some unknown reason these areas are not affected by LPPigm or, alternatively, the local reduction of melanocyte counts would lead to decreased pigment incontinence in these areas. Histopathological analysis will help to clarify this point. Finally, hypopigmentation of the eyebrows is possibly better observed in patients with dark skin types, such as the ones reported herein, due to the contrast in color.

In conclusion, we describe a series of patients presenting hypopigmentation of the eyebrow area. This new observation might be in line with Lin et al. [1] findings, suggesting a pathophysiologic connection between hair follicles in FFA and the loss of epidermal melanocytes. Sparing of the hypopigmented alopecic band and eyebrow region by LPPigm is an interesting feature that needs to be better clarified and further highlights the complexity of this disease.