**Abstract**

The aim of the treatment in frontal fibrosing alopecia and lichen planopilaris is to alleviate symptoms and to arrest the progression of the hair loss, since hair regrowth is not possible once the destruction of hair follicle has happened. Topical corticosteroids and tacrolimus are used to reduce inflammation, but with no clear benefit in slowing the alopecia. Intralesional corticosteroids may obtain hair regrowth in some patients, and they are especially useful in the treatment of eyebrow alopecia in frontal fibrosing alopecia. Regarding systemic treatments, the use of 5-alpha reductase inhibitors has been shown to be the most effective one to get stabilization in frontal fibrosing alopecia and even regrowth in the hairline. Hydroxychloroquine and oral immunomodulators are especially helpful as oral treatment in lichen planopilaris. Low-dose oral isotretinoin is the preferred treatment for facial papules in frontal fibrosing alopecia. The combination of oral and topical treatments is the best therapeutic choice.

**Keywords:** frontal fibrosing alopecia, lichen planopilaris, scarring alopecia, cicatricial alopecia, treatment

### **1. Introduction**

Frontal fibrosing alopecia (FFA) and lichen planopilaris (LPP) are currently the most common types of scarring alopecia, especially the first one [1]. LPP was first described in 1895 by Pringle [2], while FFA was described in 1994 by Kossard [3], although the latter has become the most prevalent.

Both belong to the lymphocytic cicatricial alopecia subtype and share the main histopathologic features, although there are some differences between them [4, 5]. They are mainly characterized by a lichenoid lymphocytic infiltrate around the upper follicle, that is isthmus and infundibulum, including the bulge area, where the stem cells are located, and concentric perifollicular lamellar fibrosis [6].

FFA is clinically characterized by frontal or temporoparietal hairline recession, leading to a cicatricial alopecic band without follicular openings. FFA is frequently associated with eyebrow alopecia, and sometimes eyelash alopecia or peripheral hair body loss (limbs, axillary, pubic) can be observed. Facial papules are another typical finding in FFA, which are normally distributed on the temples, but also on the cheeks or chin [7]. The classic LPP usually appears as multifocal scarring areas that may

coalesce in large alopecic areas, and which are more commonly located at the vertex and parietal scalp [5]. However, sometimes both conditions can present concomitantly, since up to 25% of patients with FFA may have also the classic form of LPP [7, 8]. Pruritus and trichodynia may be present in some patients. FFA and LPP also share some trichoscopic features, such as follicular hyperkeratosis and perifollicular erythema, which are usually more intense in LPP. The background of FFA is typically ivory-white, whereas in LPP is usually milky-red [9].

The aim of the treatment in both FFA and LPP is to alleviate symptoms – if they are present – and to stop or slow down the progression of the disease, since hair regrowth is not possible once the destruction of the hair follicle has happened. Photographic and trichoscopic control is really useful to assess the progression of the disease and the response to the treatment. Moreover, in FFA, the size of the alopecic band and the measurement from the frontal hairline to the glabella and from the temporal hairline to the eyebrows is highly advisable.
