AA is an autoimmune disease involving the hair follicle1,2

  • AA pathophysiology involves multiple immune effector cells including CD8+ T cells and natural killer cells3-5
  • Immune cells infiltrate in and around the hair bulb in a pattern called the “swarm of bees,” releasing inflammatory cytokines2,6,7
  • There are many emerging pathways of interest in AA for researchers7-10
  • The inflammation around the hair follicle is driven by inflammatory cytokines, which contribute to a cycle of sustained inflammation at the hair follicle that may lead to hair loss2,7

Pfizer does not have any approved treatments for AA.

AA is an autoimmune disease driven by an attack at the hair follicle1,2

  • AA pathophysiology involves multiple immune effector cells including CD8+ T cells and natural killer cells3-5
  • Immune cells infiltrate in and around the hair bulb in a pattern called the “swarm of bees,” releasing inflammatory cytokines2,6,7
  • There are many emerging pathways of interest in AA for researchers7-10
  • The inflammation around the hair follicle is driven by inflammatory cytokines, which contribute to a cycle of sustained inflammation at the hair follicle that may lead to hair loss2,7

Pfizer does not have any approved treatments for AA.


Watch Brett King, MD, explain more about the epidemiology and pathophysiology of AA:

Pfizer is a leader in immuno-inflammation and is working to gain a deeper understanding of AA pathophysiology

References: 1. Meah N, Wall D, York K, et al. The Alopecia Areata Consensus of Experts (ACE) study: results of an international expert opinion on treatments for alopecia areata. J Am Acad Dermatol. 2020;83(1):123-130. 2. Divito SJ, Kupper TS. Inhibiting Janus kinases to treat alopecia areata. Comment Nat Med. 2014;20(9):989-990. 3. Ito T. Recent advances in the pathogenesis of autoimmune hair loss disease alopecia areata. Clin Dev Immunol. 2013;2013:348546:1-6. 4. Bertolini M, Zilio F, Rossi A, et al. Abnormal interactions between perifollicular mast cells and CD8+ T-cells may contribute to the pathogenesis of alopecia areata. PLoS One. 2014;9(5):e94260. 5. Gilhar A, Laufer-Britva R, Keren A, Paus R. Frontiers in alopecia areata pathobiology research. J Allergy Clin Immunol. 2019;144(6):1478-1489. 6. Darwin E, Hirt PA, Fertig R, Doliner B, Delcanto G, Jimenez JJ. Alopecia areata: review of epidemiology, clinical features, pathogenesis, and new treatment options. Int J Trichology. 2018;10(2):51-60. 7. Triyangkulsri K, Suchonwanit P. Role of Janus kinase inhibitors in the treatment of alopecia areata. Drug Des Devel Ther. 2018;12:2323-2335. 8. Xu H, Jesson MI, Seneviratne UI, et al. PF-06651600, a dual JAK3/TEC family kinase inhibitor. ACS Chem Biol. 2019;14(6):1235-1242. 9. Alzolibani AA, Rasheed Z, Bin Saif G, Al-Dhubaibi MS, Al Robaee AA. Altered expression of intracellular Toll-like receptors in peripheral blood mononuclear cells from patients with alopecia areata. BBA Clin. 2016;5:134-142. 10. Seok H, Suh DW, Jo B, et al. Association between TLR1 polymorphisms and alopecia areata. Autoimmunity. 2014;47(6):372-377.