Alopecia areata

Alopecia areata: management and unmet needs

Epidemiology

Alopecia areata (AA) is non-scarring hair loss. It can manifest as total or near-total hair loss on the scalp, or on all haired bodily surfaces.

• AA affects people of all ages¹
• Children and adolescents ≤18 years of age have an overall AA prevalence of 0.05%, and commonly have a family history of AA^2,3
• Males and females are affected equally¹

The younger the age of AA onset, the increased risk of severe AA. Severe AA is comorbid with asthma, atopic dermatitis, eczema, vitiligo, psoriasis, vitamin D deficiency or anaemia^4,5.

Pathophysiology

The complete pathophysiology of AA is not known. However, AA is accepted as a T-cell-mediated autoimmune process, where hair follicles prematurely skip from the anagen phase to the telogen phase, resulting in hair loss⁶.

AA can be triggered by mental or physical stress, vaccinations or febrile illnesses, among other environmental triggers⁷.

Vascular changes, or changes in serum levels of cardiovascular biomarkers, are associated with alopecia areata pathophysiology^7,8.

Lived burden of alopecia areata

Many patients with AA are burdened with poor health-related quality of life (HRQoL)². Risk factors for low HRQoL in AA are²:

• 20–50 years of age
• change in employment
• family stress
• female sex
• hair loss >25%
• lightening of skin colour

Patients with severe AA have more adverse psychological effects than people with less severe AA¹. The risk of depression increases in people with AA aged <20 years, and risk of anxiety increases in people aged 40–59 years².

Alopecia areata diagnosis and assessment

To make an effective management plan for AA, other hair loss disorders, such as tinea capitis, trichotillomania, aplasia cutis, triangular alopecia, telogen effluvium and primary scarring alopecia need to be differentiated from AA⁹.

Identifying multiple hairs on at least five pulls of a gentle hair pull test at the periphery of a scalp patch likely indicates active progressive AA⁹.

Microscopy, trichoscopy and histopathology complement diagnostic accuracy for AA⁹.

The Severity of Alopecia Areata Tool (SALT) is widely used for visually assessing AA severity¹⁰. The Modified SALT-II is more refined than SALT¹⁰.

Mindfulness-based cognitive therapy, hypnotherapy, psychotherapy and coping strategies can improve patient quality of life and should be considered treatment options¹¹.

References

1. Harries M, Macbeth AE, Holmes S, et al. The epidemiology of alopecia areata: a population-based cohort study in UK primary care. Br J Dermatol. 2022;186(2):257–265.
2. Villasante Fricke AC, Miteva M. Epidemiology and burden of alopecia areata: a systematic review. Clin Cosmet Investig Dermatol. 2015;8:397–403.
3. Dainichi T, Kabashima K. Alopecia areata: What's new in epidemiology, pathogenesis, diagnosis, and therapeutic options? J Dermatol Sci. 2017;86(1):3–12.
4. Mirzoyev SA, Schrum AG, Davis MDP, Torgerson RR. Lifetime incidence risk of alopecia areata estimated at 2.1% by Rochester Epidemiology Project, 1990–2009. J Invest Dermatol. 2014;134(4):1141–1142.
5. Zhang T, Nie Y. Prediction of the Risk of Alopecia Areata Progressing to Alopecia Totalis and Alopecia Universalis: Biomarker Development with Bioinformatics Analysis and Machine Learning. Dermatol. 2022;238(2):386–396.
6. Simakou T, Butcher JP, Reid S, Henriquez FL. Alopecia areata: A multifactorial autoimmune condition. J Autoimmun. 2019;98:74–85.
7. Pratt CH, King LE, Jr., Messenger AG, Christiano AM, Sundberg JP. Alopecia areata. Nat Rev Dis Prim. 2017;3:17011.
8. Peterle L, Sanfilippo S, Borgia F, Cicero N, Gangemi S. Alopecia Areata: A Review of the Role of Oxidative Stress, Possible Biomarkers, and Potential Novel Therapeutic Approaches. Antiox. 2023;12(1):135.
9. Lintzeri DA, Constantinou A, Hillmann K, Ghoreschi K, Vogt A, Blume‐Peytavi U. Alopecia areata – Current understanding and management. J Deuts Dermatolo Gesell. 2022;20(1):59–90.
10. Olsen EA, Roberts J, Sperling L. Objective outcome measures: Collecting meaningful data on alopecia areata. J Am Acad Dermatol. 2018;79(3):470–478.
11. Maloh J, Engel T, Natarelli N, Nong Y, Zufall A, Sivamani RK. Systematic Review of Psychological Interventions for Quality of Life, Mental Health, and Hair Growth in Alopecia Areata and Scarring Alopecia. J Clin Med. 2023;12(3):964.