Alopecia Areata in Patients with Darker Skin

00:01 Now let's talk about alopecia areata, which falls under the non-scarring alopecia.

00:09 It's a chronic immune mediated disorder that targets anagen hair and actively dividing hair follicles that we spoke about and causes non-scarring hair loss.

00:25 It occurs in one in 1000 people worldwide, and the lifetime risk of developing alopecia areata is 2%. It is, it occurs with equal incidence between male and female, and affects children and adults of all skin and hair colors.

00:44 The peak incidence of alopecia areata is in the second and third decades.

00:50 Some of the risk factors which have been mentioned for alopecia areata include chromosomal disorders, for example, down syndrome, autoimmune conditions, family history of alopecia, and some susceptibility genes.

01:07 The exact mechanism of alopecia is unclear, but what has been postulated as a mechanism is the fact that anagen hair follicles exhibit immune privilege, meaning they are exempt from immune surveillance.

01:23 Triggers such as viral infections, hormonal imbalance, trauma, and stress can cause loss of that immune privilege.

01:31 With a loss of immune privilege, hair follicle autoantigens are exposed to surveilling T-cells. This causes an immune response that induces a premature transition from anagen into the telogen phase, leading to hair loss.

01:51 Clinical manifestations.

01:54 Alopecia areata can present as patchy alopecia areata.

01:57 This is the most common pattern.

01:59 One usually sees a well-demarcated single or several round oval patches on normal appearing skin. The usual sites that are affected are the scalp most commonly, but it may involve the beard, the eyebrows, the eyelashes, the body and the pubic areas.

02:21 Ophiasis is a pattern that we also see in patients with alopecia areata, and what one sees is a band-like area of alopecia extending across the occipital scalp at the back. This has a poor prognosis.

02:42 Sisaipho is ophiasis inversus pattern.

02:46 This involves frontal and temporal and parietal scalp, but spares hair along the scalp periphery.

02:56 The other variant of alopecia areata is alopecia totalis.

03:01 In this condition, one has complete loss of scalp hair, and it affects up to 5% of patients.

03:09 Alopecia universalis is complete loss of body hair and this affects less than 1%.

03:18 One m ay also see nail changes in patients with alopecia areata, and these occur roughly in about 10 to 40% of patients.

03:28 Clinically, ones is nail pitting and ridging.

03:33 And less commonly, koilonychia, trachyo nychia and onycholysis.

03:39 The disease course when it comes to alopecia areata, one m ay get spontaneous hair growth, and this is common.

03:47 50% of patients with limited patchy hair loss will recover within a year.

03:52 Almost all patients experience more than one episode of the disease, and it may persist for several years or indefinitely.

04:03 The diagnosis of alopecia areata is based on history, assessing the onset and duration of hair loss, as well as associated symptoms, as mentioned.

04:13 Physical examination and of course, trichoscopy, where one sees typical features like exclamation point has broken or dystrophic hairs, yellow and black dots depending on the skin color of the patient that you're examining. A hair pull test is when one pulls a few number of hairs from each side of the hair, so you grab 40 to 60 closely grouped hair and apply gentle traction.

04:45 The result is positive if more than 10% of hair is pulled out.

04:51 In some cases, a skin biopsy may be necessary.

04:56 And on histology, you see what we call a bee swarm pattern.

05:00 And these are lymphocytes that infiltrate the hair follicle and you see them surrounding the hair follicle. The differential diagnosis includes trichotillomania.

05:13 Yeah, this is a disorder characterized by an irresistible urge to remove or pull one's own hair, resulting in alopecia.

05:26 Tinea capitis, especially difficult in children with dark skin, as oiling of the scalp may hide scales of tinea capitis.

05:34 So the main differential with tinea capitis is that tinea capitis tends to be itchy and scaly. And of course, other forms of alopecia.

05:46 There's no cure for alopecia areata.

05:49 Hair loss is often associated with minimal harmful physical effects, but due to its impact on the quality of life of the patient and its psychological impact, treatment is warranted.

06:02 The following is a list of possible treatments that we use for patients with alopecia areata depending on the age, the distribution, and the extent of the lesion.

06:16 Potent topical corticosteroids have been used, especially for children, where one cannot tolerate intralesional injections, and minoxidil, up to 5% in combination with other therapies, has also been used. When one has extensive alopecia areata, topical immunotherapy using diphenyl cyclopropanone, which is applied to the affected areas to include allergic contact dermatitis, has also been used with success, and this provokes hair growth.

06:55 Systemic corticosteroids only for short-term use due to the limited known adverse effects that we experience with systemic steroids.

07:07 Lately, JAK inhibitors have been used, and they have been approved by the FDA in 2022 for use in patients with alopecia areata.