Epidemiological and clinical features of pattern III frontal fibrosing alopecia (pseudo fringe type): a multicenter series of 38 patients

FFA patients can be classified in three different clinical patterns, each one presenting different prognosis. Pattern I was defined as a “linear pattern”, in which there is a uniform frontal hairline recession. Pattern II consists of a “zig-zag band-like” alopecia and decrease of hair density. Pattern III is described as FFA presenting “pseudo fringe sign”. Those patients had their original hairline spared by the inflammatory infiltrate. Pattern III has been considered as having the best prognosis among all of them. The number of patients described in literature with this pattern is scarce. The objective of this paper was to analyze the clinical and epidemiological features of pattern III FFA patients. A multicenter retrospective, descriptive study was designed among four centers of Brazil and Spain. Patients with a confirmed diagnosis of pattern III FFA were included. The diagnosis was performed based on the updated diagnostic criteria. A total of 38 patients (37 females, one male) with a mean age of 55 years (range 31-81) were included. Clinical and epidemiological data were retrieved from patients’ medical records. Use of hormonal therapy including oral contraceptives or dihydroepiandrostenidione was reported in 13/38 (34.2%), sunscreen use in 16/31 (51.6%), while use of facial cosmetics was informed in 18/31 (58.1%). Two patients declared family history of FFA. Body hair was affected in 7/32 (21.9%) patients, while eyebrow loss was observed in 15/38 (39.5%), and eyelash loss in 1/38 (2.6%). Lichen planus pigmentosus was associated in 2/38 (5.2%) and facial papules in 15/38 (39.5%). Concomitant autoimmune diseases were present in 4/29 (13.8%). Fitzpatrick´s phototype ranged from II to IV. Of all patients, 20/29 (69%) were premenopausal women. The results for age, gender, family history, body hair loss, lichen planus pigmentosus, autoimmune diseases associated, and phototype were similar to the two largest series from the literature. Use of hormones was not addressed by the other studies. Compared to the largest studies of FFA patients4,5, our cases showed less eyebrow loss (p<0.001) and eyelash loss (p<0.05). These findings, along with the higher frequency of premenopausal women, were consistent with the results of Moreno-Arrones et al2. On the other hand, we found a higher frequency of facial papules (p<0.001) in our series. The use of moisturizers was less frequent compared to the article by Kanti et al5 (p<0.001) and we had a higher proportion of premenopausal women (p<0.05). In conclusion, FFA patients with pattern III are more frequently premenopausal and with less eyebrows and eyelashes involvement than the rest of FFA patients. To the best of our knowledge, this is the first study analyzing the main features of pattern III FFA patients.

额部纤维化性脱发（Frontal Fibrosing Alopecia，FFA）患者可分为三种不同的临床分型，各型预后存在差异。I型被定义为“线性型”，表现为发际线均匀性后退。II型为“锯齿状带状”脱发伴毛发密度降低。III型则表现为FFA出现“假性边缘征（pseudo fringe sign）”，此类患者的原始发际线未受炎性浸润累及。III型被认为是所有分型中预后最佳的类型，目前文献中报道的该型患者数量较少。

本研究旨在分析III型FFA患者的临床及流行病学特征。研究设计为多中心回顾性描述性研究，纳入巴西与西班牙四家医疗中心的确诊III型FFA患者，诊断依据最新更新的诊断标准。最终共纳入38例患者（37例女性，1例男性），平均年龄55岁（年龄范围31~81岁）。研究数据从患者的医疗记录中提取，其中13例（34.2%）患者使用过激素治疗，包括口服避孕药或脱氢表雄酮；16例（51.6%，31例有完整记录的使用者）使用过防晒霜；18例（58.1%，31例有完整记录的使用者）使用过面部化妆品。2例患者报告有FFA家族史。7例（21.9%，32例有完整记录的使用者）出现躯体毛发受累，15例（39.5%）出现眉毛脱落，1例（2.6%）出现睫毛脱落。2例（5.2%）患者合并色素性扁平苔藓（lichen planus pigmentosus），15例（39.5%）出现面部丘疹（facial papules）。4例（13.8%，29例有完整记录的使用者）合并自身免疫性疾病（autoimmune diseases）。Fitzpatrick皮肤光分型（Fitzpatrick´s phototype）范围为II~IV型。所有患者中，20例（69%，29例有完整记录的使用者）为绝经前女性。

本研究中患者的年龄、性别、家族史、躯体毛发脱落情况、色素性扁平苔藓合并率、合并自身免疫性疾病情况以及皮肤光分型结果，与文献中报道的两项最大规模队列研究结果相似。其他研究未涉及激素治疗使用情况。与既往规模最大的两项FFA患者研究[4,5]相比，本研究纳入的患者眉毛脱落率（p<0.001）与睫毛脱落率（p<0.05）均更低。这一结果，加上绝经前女性占比更高的情况，与Moreno-Arrones等人[2]的研究结果一致。另一方面，本研究队列中面部丘疹的发生率更高（p<0.001）。与Kanti等人[5]的研究相比，本研究中保湿霜的使用频率更低（p<0.001），且绝经前女性占比更高（p<0.05）。

综上，III型FFA患者更常为绝经前女性，且相较于其他分型的FFA患者，其眉毛与睫毛受累程度更轻。据我们所知，本研究是首项针对III型FFA患者主要临床特征展开分析的研究。