Contents

Search

alopecia areata

A sudden loss of hair. Etiology: 1) emotional disturbances 2) autoimmune [3] - personal history or family history of autoimmune disease - especially thyroiditis (hyperthyroidism, hypothyroidism) - vitiligo - pernicious anemia - diabetes mellitus type 1 3) atopic dermatitis Epidemiology: - generally occurs in young, otherwise health persons - generally presents befor 30 years of age Pathology: - a subset of cytotoxic T-cells attack hair follicles, through IFN-gamma pathways which act via Janus kinases [7] - preserved follicular openings Clinical manifestations: 1) often abrupt onset 2) painless loss of hair in patches 3) complete loss of hair 4) no visible effect on skin (non-scarring) 5) easily extracted hairs at the periphery - hairs may narrow close to skin at periphery 6) nail pitting may be present 7) ophiasis is a loss of hair in the shape of a wave at the circumference of the head * images [9,10,11] Complications: - increased risk of - diabetes mellitus type-1 - autoimmune thyroiditis - relapses common after initial resolution Differential diagnosis: - Tinea capitis - androgenic alopecia - discoid lupus (scarring alopecia, dyspigmented atrophic plaques) Management: 1) most cases resolve spontaneously 2) watchful wating 3) intralesional or topical steroids +/- minoxidil - systemic glucocorticoids for refractory or extensive disease [3] 4) anthralin cream may produce hair growth, but may result in dermatitis 5) photochemotherapy, topical allergens, & minoxidil have not been shown to be superior to spontaneous resolution 6) methotrexate 10-15 mg PO weekly [8] 7) JAK inhibitors - baricitinib (Olumiant) FDA-approved as of June 2022 [14] - baricitinib increases hair regrowth by >= 75% at 12-26 weeks [16] - ritlecitinib (Litfulo) approved in June 2023 for patients >= 12 - deuruxolitinib FDA-approved 2024 Clinical trials: - oral administration of Janus kinases inhibitor ruxolitinib (Jakafi) to 5 patients with alopecia areata resulted in nearly complete regrowth of hair within 5 months [7] Comparative biology: - systemic administration of Janus kinase inhibitor prevents alopecia areata in a mouse model

General

autoimmune disease alopecia (hair loss, balding)

Database Correlations

OMIM 104000

References

  1. DeGowin & DeGowin's Diagnostic Examination, 6th edition, RL DeGowin (ed), McGraw Hill, NY 1994, pg 862
  2. Saunders Manual of Medical Practice, Rakel (ed), WB Saunders, Philadelphia, 1996, pg 916-18
  3. Medical Knowledge Self Assessment Program (MKSAP) 15, 16, 17, 18, 19. American College of Physicians, Philadelphia 2009, 2012, 2015, 2018. 2022.
  4. Messenger AG et al British Association of Dermatologists' guidelines for the management of alopecia areata 2012. Br J Dermatol 2012 May;166(5):916-26 PMID: 22524397 (corresponding NGC guideline withdrawn Dec 2017)
  5. Wikipedia: Ophiasis http://en.wikipedia.org/wiki/Ophiasis
  6. Alkhalifah A, Alsantali A, Wang E, McElwee KJ, Shapiro J. Alopecia areata update: part I. Clinical picture, histopathology, and pathogenesis. J Am Acad Dermatol. 2010 Feb;62(2):177-88 PMID: 20115945
  7. Xing L et al. Alopecia areata is driven by cytotoxic T lymphocytes and is reversed by JAK inhibition. Nat Med 2014 Sep; 20:1043. PMID: 25129481
  8. Callen JP Methotrexate for Alopecia Areata NEJM Journal Watch. Feb 11, 2015 Massachusetts Medical Society (subscription needed) http://www.jwatch.org - Hammerschmidt M and Mulinari Brenner F. Efficacy and safety of methotrexate in alopecia areata. An Bras Dermatol 2014 Sep/Oct; 89:729. PMID: 25184911
  9. Alopecia areata (image) American Academy of Dermatology https://www.aad.org/public/diseases/hair-and-scalp-problems/alopecia-areata
  10. Bolduc C, Elston DM (images) Medscape: Alopecia Areata http://emedicine.medscape.com/article/1069931-overview
  11. DermNet NZ. Alopecia areata (images) http://www.dermnetnz.org/hair-nails-sweat/alopecia-areata.html
  12. Gilhar A, Etzioni A, Paus R Alopecia Areata N Engl J Med 2012; 366:1515-1525. April 19, 2012 PMID: 22512484 http://www.nejm.org/doi/full/10.1056/NEJMra1103442
  13. King B et al. Two phase 3 trials of baricitinib for alopecia areata. N Engl J Med 2022 Mar 26; [e-pub]. PMID: 35334197 https://www.nejm.org/doi/10.1056/NEJMoa2110343
  14. King B et al. Two phase 3 trials of baricitinib for alopecia areata. N Engl J Med 2022 Mar 26; [e-pub]. PMID: 35334197 https://www.nejm.org/doi/10.1056/NEJMoa2110343 - Frellick M FDA OKs First Systemic Treatment for Alopecia Areata, Medscape. June 13, 2022 https://www.medscape.com/viewarticle/975487
  15. Strazzulla LC, Wang EH, Avila L, et al. Alopecia areata: disease characteristics, clinical evaluation, and new perspectives on pathogenesis. J Am Acad Dermatol. 2018;78:1-12. PMID: 29241771
  16. Mateos-Haro M, Novoa-Candia M, Sanchez Vanegas G et al Treatments for alopecia areata: a network meta-analysis. Cochrane Database Syst Rev. 2023 Oct 23;10(10):CD013719. PMID: 37870096 Review.
  17. Alopecia Areata https://www.niams.nih.gov/health-topics/alopecia-areata - National Alopecia Areata Foundation http://www.naaf.org
  18. National Alopecia Areata Foundation http://www.naaf.org/site/PageServer