Alopecia in Autoimmune Blistering Diseases: A Systematic Review of Pathogenesis and Clinical Features of Disease

Abstract

Background: Autoimmune blistering diseases (AIBD) are characterised by the body's production of autoantibodies against structural proteins in the epidermis and/or the basement membrane on cutaneous and mucosal surfaces. Alopecia is a complication of AIBD that has generally been overlooked in patients with severe blistering diseases because it is regarded as a cosmetic issue. Yet recent research into quality of life tools has found that stigmatisation by appearance plays a significant role in blistering diseases. Aim: To review the current literature detailing the pathogenesis and clinical presentations of alopecia in AIBD patients. Method: We searched Medline, PubMed and EMBASE electronic databases up to September 2018, for empirical human and animal studies. Results: Only 36 human studies including 223 patients (190 pemphigus, 25 pemphigoid, 5 epidermolysis bullosa acquisita, 2 dermatitis herpetiformis and 1 linear IgA disease) detailed demographic and clinical manifestations of alopecia. A range of hair evaluation methods was demonstrated to reach alopecia diagnosis. Furthermore, with no universal validated scoring system for alopecia severity, alopecia patterns have been summarised. Conclusion: Previous randomised trials have not highlighted alopecia as an important outcome of AIBD, so epidemiological evaluation of the available literature has been helpful in summarising trends between existing studies and demonstrating inconsistencies.