Female Androgenetic Alopecia: An Update on Diagnosis and Management

Michela Starace; Gloria Orlando; Aurora Alessandrini; Bianca Maria Piraccini


Am J Clin Dermatol. 2020;21(1):69-84. 

In This Article

Differential Diagnosis

Multiple hair disorders may be present with clinical features that resemble FAGA. Moreover, FAGA can coexist with other disorders. The main differential diagnoses include telogen effluvium (TE), diffuse or incognita areata alopecia (AA) and cicatricial alopecias that can be present in a FAGA distribution.

Telogen Effluvium

TE is caused by the early entry of anagen hair into the telogen phase, leading to increased shedding. It is typically subsequent to a stressful event (emotional difficulties, pregnancy, recent surgery, viral infections), or caused by drugs, malnutrition or endocrine disorders. In the acute form, hair loss is evident 2–3 months following the trigger event, and full regrowth is seen after 6–12 months; whereas chronic TE can persists for 6 months or more.

Although it may be most evident in the temporal area, the hair loss occurs in all areas of the scalp.[41] A hair pull test often demonstrates increased shedding of telogen hairs. There are no specific trichoscopic signs to detect (Figure 7). Of note, an episode of acute TE can reveal underlying FAGA.[42]

Figure 7.

In telogen effluvium, all of the scalp can be affected (a) but the disease is more evident in the temporal area (b)

Diffuse and Incognita Alopecia Areata

Diffuse and incognita AA are autoimmune disorders histologically characterized by infiltration of Th1 cells around and within the hair follicles. They lack the characteristic patches of classical AA and instead demonstrate widespread scalp hair thinning.[43] Due to the preferential loss of pigmented hairs, adult patients may complain of rapid greying of the hair. Pull test is usually positive. Trichoscopy shows diffuse yellow dots, black dots and dystrophic hair. A biopsy is useful to confirm the diagnosis (Figure 8).

Figure 8.

Diffuse areata alopecia (AA) is characterized by a diffuse hair thinning (a) and trichoscopy shows diffuse yellow dots with dystrophic hair (b) (×20 magnification)

Cicatricial Alopecias With a Female Pattern Distribution

Fibrosing Alopecia in Pattern Distribution (FAPD). In 2000, Zinkernagel and Truëb described 19 patients aged from 35 to 74 years—15 women and 4 men—with a form of progressive scarring alopecia limited to the area of FAGA and named FAPD.[4] FAPD is usually presented with diffuse hair thinning on the central scalp associated with itching.[4] Trichoscopy shows perifollicular erythema, follicular keratosis and loss of follicular orifices limited to the involved area (Figure 9). Histology shows hair follicle miniaturization and a lichenoid inflammatory infiltrate with perifollicular lamellar fibrosis targeting the isthmus and the infundibular region, indistinguishable from LPP. Since its first description, several cases of FAPD have been reported.[44–46]

Figure 9.

a Clinically evident hair thinning and mild erythema in the crown area in a subject with fibrosing alopecia in pattern distribution (FAPD). b Trichoscopy shows peripilar casts, perifollicular erythema and hyperkeratosis. Miniaturized hair and diameter variability are lacking (×20 magnification)

Cicatricial Pattern Hair Loss (CPHL). In 2005, Olsen coined the term CPHL to describe a form of cicatricial alopecia in a case of FPHL, lacking the perifollicular erythema and follicular hyperkeratosis seen in FAPD.[5] Typically, it affects women over 40 years and the specific trichoscopical sign is the presence of small "pencil–eraser-sized" areas of focal atrichia[5] (Figure 10). Histological examination shows perifollicular lymphocytic infiltrate surrounding the isthmus, sebaceous gland loss and concentric lamellar fibrosis.[5,47]

Figure 10.

a Hair thinning of the central scalp in a patient with cicatricial pattern hair loss (CPHL). b Trichoscopy shows fibrotic areas and loss of follicular ostia, absence of diameter variability and perifollicular erythema and hyperkeratosis (20× magnification)

Central Centrifugal Cicatricial Alopecia (CCCA). CCCA is a lymphocytic cicatricial alopecia presenting primarily in African Americans in the second or third decade of life.[48] Clinically it begins in the central midline scalp and slowly progresses centrifugally. In the advanced stages the affected scalp is smooth and shiny and there is progressive loss of follicular ostia. Itching and pain can be associated.

Olsen has hypothesized that these women may have underlying FAGA that becomes inflammatory with the use of some hair care practices, such as hot combs, relaxers and occlusive ointment, leading to a cicatricial type of hair loss.[49,50]

Trichoscopy shows peripilar white/grey halos, a honey-comb pigmented network, point–point white dots, white patches and variability in the hair shafts. Inflammatory signs, such as perifollicular erythema and follicular keratosis, can be present[5] (Figure 11).

Figure 11.

Typical case of central centrifugal cicatricial alopecia (CCCA): clinical presentation (a) and trichoscopy (b) (×20 magnification)

Frontal Fibrosing Alopecia (FFA). FFA, first described by Kossard in 1994,[6] is permanent cicatricial alopecia of unknown etiology. Hormonal milieu, genetic predisposition, environmental factors and autoimmunity have been supposed to be involved.[51] It affects mainly middle-aged post-menopausal women, although it has been reported both in males and in premenopausal women.[52] The incidence of the disease is increasing in Europe, the United States and Asia.

FFA is considered a clinical variant of LPP lacking the well defined areas of alopecia typical of LPP. Clinically, it is characterized by a progressive recession of the fronto-temporal hairline, similar to some forms of male AGA. However, this pattern has rarely been described in FAGA as well.[5]

Loss of eyebrows, eyelashes and peripheral body hair is often associated with FFA. Eyebrow alopecia could be the initial manifestation of the disease.[53] Non-inflammatory facial papules are reported in about one third of all cases.[53] Up to 90% of patients report subjective symptoms in the affected area, such as itching and trichodynia.[53] The association with FAGA is often reported.

The pull test can show dystrophic anagen roots, but it is usually negative. Trichoscopy shows perifollicular erythema, follicular hyperkeratosis, white patches and absence of follicular ostia in the fronto-temporal hairline (Figure 12). 'Lonely hair' could be seen in the scarring area.

Figure 12.

A case of frontal fibrosing alopecia (FFA) with eyebrow involvement (a): at trichoscopy, perifollicular erythema and hyperkeratosis with absence of follicular ostia is evident (b) (×20 magnification)

Histology shows a typical lichenoid perifollicular lymphocytic infiltrate associated with perifollicular lamellar fibrosis involving predominantly the vellus hair follicles.

The main features of FAGA and cicatricial alopecias with a female pattern distribution are listed in Table 1.