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Alopecia Areata

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Last Update: October 30, 2023.

Continuing Education Activity

Alopecia areata, an autoimmune disorder, is characterized by sudden and patchy hair loss, which can affect any hair-bearing area of the body. This condition results from the immune system mistakenly attacking hair follicles, leading to hair loss without permanent damage to the follicles. Alopecia areata often presents as isolated, smooth, nonscarring patches of hair loss, typically on the scalp, but it can occur anywhere with hair growth.

This CME activity on alopecia areata is designed to equip healthcare professionals with comprehensive knowledge of the condition, focusing not only on the pathophysiology, clinical manifestations, and treatment strategies but also on addressing the critical aspects of patient communication, expectations, and emotional support. Participants will gain expertise in different treatment modalities, including the use of corticosteroids, immunotherapy, and JAK inhibitors, improving their ability to provide the best care for patients with alopecia areata. By emphasizing interprofessional collaboration and holistic management, this course aims to enhance clinician-patient interactions, leading to more informed treatment decisions, improved patient outcomes, and an enhanced quality of life for individuals with alopecia areata. 

Objectives:

  • Identify the clinical manifestations and presentation of alopecia areata to ensure accurate diagnosis.
  • Differentiate between alopecia areata and other forms of alopecia, such as androgenetic alopecia or traction alopecia, through a comprehensive evaluation.
  • Implement evidence-based treatment strategies for alopecia areata, considering the severity and extent of hair loss, patient preferences, and potential adverse effects.
  • Collaborate with primary care, dermatology, endocrinology, and mental health professionals to address the emotional impact of alopecia areata, including depression and anxiety, and provide appropriate support and comprehensive care for patients.
Access free multiple choice questions on this topic.

Introduction

Alopecia areata is a chronic, immune-mediated condition affecting hair follicles, nails, and, occasionally, the retinal pigment epithelium.[1] This condition results from the immune system mistakenly attacking hair follicles, leading to hair loss without permanent damage to the follicles. The typical manifestation of alopecia areata often includes isolated, smooth, nonscarring patches of hair loss on the scalp or any area with hair growth.[2] While many individuals with alopecia areata experience spontaneous hair regrowth within a year, it is a chronic condition with recurring episodes of hair loss. Various treatment options are available, including corticosteroids, immunotherapy, Janus kinase (JAK) inhibitors, and topical solutions, to manage the extent and duration of hair loss.

This alopecia areata overview is designed to equip healthcare professionals with comprehensive knowledge of the condition, focusing not only on the pathophysiology, clinical manifestations, and treatment strategies but also on addressing the critical aspects of patient communication, expectations, and emotional support. 

Etiology

The hair cycle has 3 phases—anagen, catagen, and telogen. During the anagen phase, active hair growth occurs, whereas during the catagen phase, the keratinization of the proximal end of the hair shaft takes place. Subsequently, the hair follicle sheds, and the remaining proximal end undergoes apoptosis. Telogen represents the interval between the regression of the old follicle and the onset of the next anagen phase.

During the anagen phase, there are 6 stages of hair growth, with stage VI representing a fully formed anagen follicle. Notably, alopecia areata is an autoimmune disorder that affects this process. However, in individuals with alopecia areata, the hair follicles become arrested in stages III or IV, prematurely reverting to the catagen or telogen phase. This leads to abrupt hair loss and a deficiency of hair regrowth.

Epidemiology

The lifetime risk of developing alopecia areata in the general population is estimated at 2%, with a prevalence of approximately 1 in 1000.[3][4] Although data indicate no demonstrable sex predilection, they reveal a higher incidence among Asian, Black, and Hispanic patients.

Alopecia areata can affect both children and adults, and its incidence rises steadily with age, with a mean onset occurring at the age of 32 in males and 36 in females.[5] 

Pathophysiology

Certain critical body organs, including the eyes, central nervous system, testicles, fetus, and placenta, display immune privilege, which is the ability to endure exposure to antigens without eliciting an inflammatory immune response. The loss of immune privilege within hair follicles and the subsequent immune dysregulation play a central role in the development of alopecia areata.[3][4]

Current evidence suggests that the cause of the condition is autoimmune, with a significant genetic contribution, which is further influenced by unknown environmental factors. Reported triggers include emotional or physical stress, vaccinations, viral infections, and medications.[1] These triggers inhibit the production of 2 anti-inflammatory cytokines—transforming growth factor-beta (TGF-β) and alpha-melanocyte-stimulating hormone (α-MSH). Furthermore, there is an increased expression of major histocompatibility complex class I (MHC-I) polypeptide-related sequence A (MICA) on hair follicles. Subsequently, natural killer cells become activated, leading to the secretion of interferon-gamma (IFN-γ) and interleukin (IL)-15.

IFN-γ stimulates the expression of MHC-I proteins on hair follicle cells, revealing previously hidden antigens to T cells. Notably, IL-15 inhibits regulatory T cells. IFN-γ and IL-15 activate target immune cells via the JAK-signal transducer and activator of the transcription (JAK-STAT) signaling pathway. As a result, inflammatory cells target the hair follicle matrix epithelium undergoing early cortical differentiation (anagen hair follicles), prematurely pushing them into the catagen or telogen phase.

Histopathology

The histopathological observations in acute active hair loss areas reveal a distinctive "bee-swarm pattern" characterized by dense lymphocytic infiltrates surrounding the bulbar region of anagen hair follicles (see Image. Alopecia Areata Biopsy).[1] The lymphocytic infiltrate comprises CD8+ T cells within the follicular epithelium and CD4+ T cells around the hair follicles.[6] Biopsies from regions affected by chronic alopecia reveal follicular miniaturization. 

History and Physical

Alopecia areata typically manifests as isolated patches of hair loss on the scalp that develop over a few weeks (see Image. Alopecia Areata). However, this condition can also affect the beard, eyebrows, eyelashes, and extremities (see Image. Alopecia Areata Hair Loss). Exclamation-mark hairs, characterized by a narrower proximal end than the distal end, are typically observed at the periphery of lesions during active disease.[3] A minority of patients may progress to total hair loss on the scalp—a condition referred to as alopecia areata totalis. In addition, some individuals may encounter complete hair loss over the entire body—a condition referred to as alopecia universalis.

There are various types of alopecia areata, as mentioned below.

Ophiasis: Hair loss that affects the occipital region.

Sisaipho (ophiasis inversus) pattern: Hair loss that involves the frontal, temporal, and parietal scalp, but spares the occipital region.

Diffuse: Rapidly progressive and diffuse hair loss followed by regrowth within several months.[1]

Approximately 10% to 15% of patients experience nail involvement, characterized by fine nail pitting, trachyonychia, onychorrhexis, red spotting on the lunulae, onycholysis, and onychomadesis (see Image. Alopecia Areata Dystrophic Nails).

Individuals with alopecia areata also have an elevated risk of experiencing conditions such as retinal detachment, retinal vein occlusion, and retinopathy.[7]

Evaluation

The diagnosis of alopecia areata is typically established clinically based on a patient's medical history and physical examination. Clinical suspicion should be heightened when a patient presents with the rapid development of individual patches of alopecia on the skin, often accompanied by little to no erythema. Dermoscopy can serve as a valuable complementary diagnostic tool.[8][9]

Early regrowth is indicated by yellow dots, black dots, broken hairs, exclamation point hairs, and short vellus hairs, which are the key findings during diagnosis.[10] A skin biopsy from the periphery of an active hair loss patch may be beneficial if the diagnosis remains uncertain.[1] Although alopecia areata is associated with other autoimmune diseases, current evidence does not advocate for routine screening unless the patient's clinical history suggests their presence.[4]

Treatment / Management

Within one year, approximately 50% of patients will experience spontaneous hair regrowth without treatment, and some may choose not to pursue it. For individuals who opt for treatment, intralesional and topical corticosteroids are often the first-line therapy for most cases of patchy alopecia areata.

Triamcinolone acetonide at concentrations of 5 to 10 mg/mL, administered every 4 to 6 weeks on the scalp, has been shown to stimulate localized regrowth in 60% to 67% of cases.[1] Triamcinolone concentrations of 2.5 to 5 mg/mL are typically utilized for the eyebrows and beard. New hair growth is commonly observed within 6 to 8 weeks. A study comparing various concentrations of intralesional triamcinolone acetonide (2.5 mg/mL, 5 mg/mL, and 10 mg/mL) for treating scalp alopecia areata found similar hair regrowth rates irrespective of the concentration used. However, it is noteworthy that the risk of cutaneous atrophy was more significant with higher triamcinolone concentrations (10 mg/mL).[11] 

Although the use of intralesional betamethasone has been proposed, further studies are required to assess its efficacy.[12] The adverse effects of corticosteroids may encompass localized skin atrophy, pain, and depigmentation. The use of intralesional corticosteroids on the face can result in significant hypopigmentation in individuals with darkly pigmented skin. Although localized skin atrophy may resolve within a few months, it is common for relapses to occur after treatment discontinuation.

Betamethasone dipropionate 0.05% is a potent topical glucocorticoid used in the treatment of alopecia areata. Topical corticosteroids are typically reserved for children and patients who cannot tolerate the numerous injections required. Patients affected by the condition apply betamethasone daily for 3 months, and in cases where no improvement is observed, discontinuation of its use is advised. However, in cases where progress is noticeable, patients are recommended to continue using betamethasone while gradually reducing the dosage.

Patients with extensive disease, typically defined as having more than 50% scalp hair loss, may consider treatment options such as topical immunotherapy or oral baricitinib to avoid the necessity of numerous injections associated with intralesional corticosteroids. Moreover, a retrospective study revealed the superior efficacy of topical immunotherapy compared to intralesional corticosteroids in patients with hair loss patches exceeding 50 cm².[13]

A potent contact allergen, such as diphenylcyclopropenone (DPCP) or squaric acid dibutyl ester (SADBE), can be applied weekly to the scalp to stimulate hair regrowth. Subsequently, hair growth can be observed approximately 3 months after treatment initiation, although it is noteworthy that severe dermatitis is a potential adverse effect. A recent meta-analysis assessing clinical outcomes on contact immunotherapy for alopecia areata showed that 74.6% of patients with patchy alopecia experienced hair regrowth, compared to 54.4% of patients with alopecia totalis and alopecia universalis. The recurrence rates were 38.2% in patients who received maintenance treatment, in contrast to 49% among those who did not receive the maintenance treatment.[14]

Oral baricitinib, a selective and reversible JAK1 and JAK2 inhibitor, treats alopecia areata by suppressing the activation of T lymphocytes. Patients typically require ongoing therapy to sustain the benefits achieved. The U.S. Food and Drug Administration (FDA) has issued a boxed warning for JAK inhibitors, cautioning about the risk of serious infections, mortality, malignancy, major adverse cardiovascular events, and thrombosis. Additional therapies that have shown some efficacy include topical or oral minoxidil, platelet-rich plasma, anthralin, the excimer laser, and PUVA.[15][16][17][18][19][20][21]

Systemic glucocorticoids may promote hair growth but are not widely used due to their adverse effects. However, patients experiencing rapid and extensive hair loss may find oral glucocorticoids beneficial. Furthermore, relapse occurs within a year in approximately one-third of responsive patients, and the likelihood of relapses tends to increase over time.[21][1] Other systemic therapies, including methotrexate, cyclosporine, azathioprine, and etanercept, have demonstrated variable clinical responses. Ongoing investigational treatments include recombinant IL-2, hydroxychloroquine, and simvastatin with ezetimibe.[17][18][19][20][21]

Currently, no effective topical therapy exists for eyelashes. Some individuals may experience improvement with systemic therapy, whereas another option to consider is using false eyelashes. Additional cosmetic alternatives encompass tattooed eyebrows, wigs, hairpieces, and head shaving.

Alopecia areata can be distressing and may result in anxiety and depression for some individuals. In such cases, the involvement of a psychologist or psychiatric provider may be necessary. Support is also available through the National Alopecia Areata Foundation at https://www.naaf.org/.

Differential Diagnosis

Specific medical conditions that may be mistaken for alopecia areata are as follows:

  • Androgenetic alopecia
  • Traction alopecia
  • Trichotillomania
  • Tinea capitis
  • Secondary syphilis
  • Aplasia cutis
  • Temporal triangular alopecia

Prognosis

Patients with alopecia areata still have the potential for hair regrowth, as 34% to 50% of individuals experience spontaneous recovery within one year. Recurrent episodes are common in patients with alopecia, with up to 25% of patients eventually progressing to alopecia totalis or universalis, whereas less than 10% attain full recovery.[1]

The extent of hair loss and the age at which the patient is diagnosed with alopecia areata are critical prognostic factors. Diagnoses made during childhood and an ophiasis distribution indicate an unfavorable prognosis.[4] A family history of alopecia areata, nail dystrophy, atopy, or concomitant autoimmune disease may indicate a poor prognosis.[3][22]

Complications

 Some potential complications of alopecia areata include the following symptoms:

  • Depression and anxiety
  • Permanent hair loss
  • Unpredictable pattern, texture, and rate of hair regrowth
  • Recurrence
  • Increased risk of developing thyroid disease, vitiligo, psoriasis, lupus erythematosus, and atopic dermatitis [23][24]
  • Nail abnormalities
  • Sunburn and skin damage
  • Skin atrophy, hypopigmentation, infections, malignancy, dermatitis, and thrombosis due to adverse effects of medication
  • A 3-fold more significant risk of developing retinal diseases, including retinal detachment, retinal vascular occlusion, and retinopathy, is observed in patients with alopecia areata.[7]

Deterrence and Patient Education

Alopecia areata is an autoimmune condition that leads to sudden and patchy hair loss, which can affect any body part. This condition arises from a malfunction in the body's natural defense mechanisms. The positive aspect is that the hair follicles are not permanently damaged, indicating that regrowth is attainable. Around half of the individuals affected by alopecia areata experience spontaneous hair regrowth within a year.

Currently, alopecia areata has no cure, and many individuals with this condition will encounter recurring episodes of hair loss throughout their lives. However, not everyone affected by alopecia areata requires or desires treatment, and for those who do, multiple treatment options are available.

Cosmetic choices can help individuals manage the appearance of hair loss, and these options include:

  • High-quality wigs and hairpieces that offer a natural appearance and boost confidence.
  • Individuals with eyelash involvement can enhance the eye area by using false eyelashes.
  • Tattooed eyebrows offer a permanent solution for addressing eyebrow hair loss.

Several medications available for managing alopecia areata include:

  • Corticosteroids applied topically or injected into affected areas can reduce inflammation and encourage hair regrowth.
  • Topical immunotherapy stimulates the immune system to facilitate hair growth.
  • Anthralin application in the affected areas can promote hair regrowth.
  • Minoxidil, whether taken orally or applied topically, may occasionally aid in hair regrowth.
  • Oral JAK inhibitors are a newer treatment option prescribed for more severe cases of alopecia areata.

Hair loss, particularly when noticeable, can evoke emotional distress and potentially give rise to feelings of depression and anxiety. In such situations, seeking emotional support by consulting with a psychologist or psychiatric provider or participating in a support group is crucial. Connecting with individuals who relate to this experience can offer valuable emotional support.

Enhancing Healthcare Team Outcomes

Primary care clinicians frequently encounter alopecia areata, and its overall impact can lead to distress for patients, necessitating both psychosocial and medical interventions. Involving a psychologist or psychiatric healthcare professional can be instrumental in alleviating symptoms of depression and anxiety in patients experiencing alopecia areata.[25] Providing resources for additional information and community support can help mitigate feelings of isolation.

Although treatment options are available, none of them can provide rapid results. In addition, treatment responses can vary, and most treatments have potential adverse effects. Shared decision-making among patients and their healthcare providers is essential in determining whether to pursue the treatment, with a focus on establishing realistic expectations for the patient. Due to the association of alopecia areata with other autoimmune diseases, clinicians should remain vigilant for potential symptoms and conduct appropriate testing when necessary. Providing comprehensive care for patients with alopecia areata involves addressing the psychosocial and physical aspects while monitoring for commonly associated illnesses.

Review Questions

Image

Figure

Alopecia Areata Contributed by Shyam Verma, MBBS, DVD, FRCP, FAAD

Image

Figure

Alopecia Areata Dystrophic Nails Contributed by Ronald Rapini, MD

Alopecia Areata Hair Loss

Figure

Alopecia Areata Hair Loss. Patches of hair loss seen in alopecia areata. Contributed by Hasnain Ali Syed, MD

Alopecia Areata Biopsy

Figure

Alopecia Areata Biopsy. Lymphocytes are clustered around the hair papilla at the base of the hair follicle, often called a "swarm of bees," found in early or active cases. Contributed by Ronald Rapini, MD

References

1.
Gilhar A, Etzioni A, Paus R. Alopecia areata. N Engl J Med. 2012 Apr 19;366(16):1515-25. [PubMed: 22512484]
2.
Zhou C, Li X, Wang C, Zhang J. Alopecia Areata: an Update on Etiopathogenesis, Diagnosis, and Management. Clin Rev Allergy Immunol. 2021 Dec;61(3):403-423. [PubMed: 34403083]
3.
Safavi KH, Muller SA, Suman VJ, Moshell AN, Melton LJ. Incidence of alopecia areata in Olmsted County, Minnesota, 1975 through 1989. Mayo Clin Proc. 1995 Jul;70(7):628-33. [PubMed: 7791384]
4.
Pratt CH, King LE, Messenger AG, Christiano AM, Sundberg JP. Alopecia areata. Nat Rev Dis Primers. 2017 Mar 16;3:17011. [PMC free article: PMC5573125] [PubMed: 28300084]
5.
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 Apr;134(4):1141-1142. [PMC free article: PMC3961558] [PubMed: 24202232]
6.
Rajabi F, Drake LA, Senna MM, Rezaei N. Alopecia areata: a review of disease pathogenesis. Br J Dermatol. 2018 Nov;179(5):1033-1048. [PubMed: 29791718]
7.
Ting HC, Ma SH, Tai YH, Dai YX, Chang YT, Chen TJ, Chen MH. Association between alopecia areata and retinal diseases: A nationwide population-based cohort study. J Am Acad Dermatol. 2022 Oct;87(4):771-778. [PubMed: 34794815]
8.
Fernández-Domper L, Ballesteros-Redondo M, Vañó-Galván S. Trichoscopy: An Update. Actas Dermosifiliogr. 2023 Apr;114(4):327-333. [PubMed: 36574917]
9.
Bains P, Kaur S. The Role of Dermoscopy in Severity Assessment of Alopecia Areata: A Tertiary Care Center Study. J Clin Aesthet Dermatol. 2020 Apr;13(4):45-50. [PMC free article: PMC7605386] [PubMed: 33144912]
10.
Gómez-Quispe H, Muñoz Moreno-Arrones O, Hermosa-Gelbard Á, Vañó-Galván S, Saceda-Corralo D. Trichoscopy in Alopecia Areata. Actas Dermosifiliogr. 2023 Jan;114(1):25-32. [PubMed: 36067826]
11.
Chu TW, AlJasser M, Alharbi A, Abahussein O, McElwee K, Shapiro J. Benefit of different concentrations of intralesional triamcinolone acetonide in alopecia areata: An intrasubject pilot study. J Am Acad Dermatol. 2015 Aug;73(2):338-40. [PubMed: 26183987]
12.
Melo DF, Dutra TBS, Baggieri VMAC, Tortelly VD. Intralesional betamethasone as a therapeutic option for alopecia areata. An Bras Dermatol. 2018 Mar;93(2):311-312. [PMC free article: PMC5916422] [PubMed: 29723356]
13.
Ro BI. Alopecia areata in Korea (1982-1994). J Dermatol. 1995 Nov;22(11):858-64. [PubMed: 8557859]
14.
Lee S, Kim BJ, Lee YB, Lee WS. Hair Regrowth Outcomes of Contact Immunotherapy for Patients With Alopecia Areata: A Systematic Review and Meta-analysis. JAMA Dermatol. 2018 Oct 01;154(10):1145-1151. [PMC free article: PMC6233743] [PubMed: 30073292]
15.
Sharma AN, Michelle L, Juhasz M, Muller Ramos P, Atanaskova Mesinkovska N. Low-dose oral minoxidil as treatment for non-scarring alopecia: a systematic review. Int J Dermatol. 2020 Aug;59(8):1013-1019. [PubMed: 32516434]
16.
Stoehr JR, Choi JN, Colavincenzo M, Vanderweil S. Off-Label Use of Topical Minoxidil in Alopecia: A Review. Am J Clin Dermatol. 2019 Apr;20(2):237-250. [PubMed: 30604379]
17.
Strazzulla LC, Avila L, Lo Sicco K, Shapiro J. An Overview of the Biology of Platelet-Rich Plasma and Microneedling as Potential Treatments for Alopecia Areata. J Investig Dermatol Symp Proc. 2018 Jan;19(1):S21-S24. [PubMed: 29273100]
18.
Cervantes J, Jimenez JJ, DelCanto GM, Tosti A. Treatment of Alopecia Areata with Simvastatin/Ezetimibe. J Investig Dermatol Symp Proc. 2018 Jan;19(1):S25-S31. [PubMed: 29273101]
19.
Iorizzo M, Tosti A. Emerging drugs for alopecia areata: JAK inhibitors. Expert Opin Emerg Drugs. 2018 Mar;23(1):77-81. [PubMed: 29466675]
20.
Perper M, Aldahan AS, Fayne RA, Emerson CP, Nouri K. Efficacy of fractional lasers in treating alopecia: a literature review. Lasers Med Sci. 2017 Nov;32(8):1919-1925. [PubMed: 28812164]
21.
Putterman E, Castelo-Soccio L. Topical 2% tofacitinib for children with alopecia areata, alopecia totalis, and alopecia universalis. J Am Acad Dermatol. 2018 Jun;78(6):1207-1209.e1. [PubMed: 29754888]
22.
Madani S, Shapiro J. Alopecia areata update. J Am Acad Dermatol. 2000 Apr;42(4):549-66; quiz 567-70. [PubMed: 10727299]
23.
Lee S, Lee H, Lee CH, Lee WS. Comorbidities in alopecia areata: A systematic review and meta-analysis. J Am Acad Dermatol. 2019 Feb;80(2):466-477.e16. [PubMed: 30031145]
24.
Kyritsi EM, Kanaka-Gantenbein C. Autoimmune Thyroid Disease in Specific Genetic Syndromes in Childhood and Adolescence. Front Endocrinol (Lausanne). 2020;11:543. [PMC free article: PMC7466763] [PubMed: 32973676]
25.
Mulinari-Brenner F. Psychosomatic aspects of alopecia areata. Clin Dermatol. 2018 Nov-Dec;36(6):709-713. [PubMed: 30446192]

Disclosure: Kenia Lepe declares no relevant financial relationships with ineligible companies.

Disclosure: Hasnain Syed declares no relevant financial relationships with ineligible companies.

Disclosure: Patrick Zito declares no relevant financial relationships with ineligible companies.

Copyright © 2024, StatPearls Publishing LLC.

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