[Alopecia universalis in an adult after routine tetanus toxoid vaccine]

Alopecia universalis after injection of messenger RNA COVID-19 vaccine. A case report

Messenger RNA vaccines against SARS-CoV-2 infection, or COVID-19 dramatically changed the landscape of the fight against COVID-19 pandemic. However, they might be associated with various side effects, such as myocarditis. Herein we report a case of alopecia universalis occurring after injection of an mRNA COVID-19 vaccine in a Japanese patient. Healthcare workers should be aware of this rather rare complication after vaccinations.

Alopecia areata after COVID-19 vaccination

The coronavirus disease 2019 (COVID-19) vaccines are authorized for use in numerous countries worldwide. Several cutaneous findings are reported after severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) vaccination. Here, we report the case of a patient with a rapid onset of alopecia areata immediately after receiving the second dose of the COVID-19 vaccine. Alopecia areata is a common autoimmune disease leading to non-scarring hair loss. Among the many cutaneous adverse effects reported after the anti-SARS-COV2 vaccination, no episodes of alopecia areata have been described to date. In this paper, we report the first case of alopecia areata after COVID-19 vaccination described in the literature with a revision of cases of alopecia areata reported after other types of vaccination. Although the significance of these skin reactions is not yet known, further studies will certainly clarify whether the development of alopecia areata or other forms of immune-mediated reactions could represent a positive prognostic factor regarding immune protection from SARS-CoV-2.

Alopecia areata: A multifactorial autoimmune condition

Alopecia areata is an autoimmune disease that results in non-scarring hair loss, and it is clinically characterised by small patches of baldness on the scalp and/or around the body. It can later progress to total loss of scalp hair (Alopecia totalis) and/or total loss of all body hair (Alopecia universalis). The rapid rate of hair loss and disfiguration caused by the condition causes anxiety on patients and increases the risks of developing psychological and psychiatric complications. Hair loss in alopecia areata is caused by lymphocytic infiltrations around the hair follicles and IFN-γ. IgG antibodies against the hair follicle cells are also found in alopecia areata sufferers. In addition, the disease coexists with other autoimmune disorders and can come secondary to infections or inflammation. However, despite the growing knowledge about alopecia areata, the aetiology and pathophysiology of disease are not well defined. In this review we discuss various genetic and environmental factors that cause autoimmunity and describe the immune mechanisms that lead to hair loss in alopecia areata patients.

Alopecia areata

Alopecia areata is an autoimmune disorder characterized by transient, non-scarring hair loss and preservation of the hair follicle. Hair loss can take many forms ranging from loss in well-defined patches to diffuse or total hair loss, which can affect all hair-bearing sites. Patchy alopecia areata affecting the scalp is the most common type. Alopecia areata affects nearly 2% of the general population at some point during their lifetime. Skin biopsies of affected skin show a lymphocytic infiltrate in and around the bulb or the lower part of the hair follicle in the anagen (hair growth) phase. A breakdown of immune privilege of the hair follicle is thought to be an important driver of alopecia areata. Genetic studies in patients and mouse models have shown that alopecia areata is a complex, polygenic disease. Several genetic susceptibility loci were identified to be associated with signalling pathways that are important to hair follicle cycling and development. Alopecia areata is usually diagnosed based on clinical manifestations, but dermoscopy and histopathology can be helpful. Alopecia areata is difficult to manage medically, but recent advances in understanding the molecular mechanisms have revealed new treatments and the possibility of remission in the near future.

Alopecia Areata After Vaccination: Recurrence with Rechallenge

Alopecia areata (AA) is the most common form of hair loss in children. We report the case of a child who had two episodes of AA after two different vaccines with complete hair regrowth between the episodes. This case supports the concept that vaccination might be a trigger for the development of AA in genetically predisposed children.

Vaccines, adjuvants and autoimmunity

Vaccines and autoimmunity are linked fields. Vaccine efficacy is based on whether host immune response against an antigen can elicit a memory T-cell response over time. Although the described side effects thus far have been mostly transient and acute, vaccines are able to elicit the immune system towards an autoimmune reaction. The diagnosis of a definite autoimmune disease and the occurrence of fatal outcome post-vaccination have been less frequently reported. Since vaccines are given to previously healthy hosts, who may have never developed the disease had they not been immunized, adverse events should be carefully accessed and evaluated even if they represent a limited number of occurrences. In this review of the literature, there is evidence of vaccine-induced autoimmunity and adjuvant-induced autoimmunity in both experimental models as well as human patients. Adjuvants and infectious agents may exert their immune-enhancing effects through various functional activities, encompassed by the adjuvant effect. These mechanisms are shared by different conditions triggered by adjuvants leading to the autoimmune/inflammatory syndrome induced by adjuvants (ASIA syndrome). In conclusion, there are several case reports of autoimmune diseases following vaccines, however, due to the limited number of cases, the different classifications of symptoms and the long latency period of the diseases, every attempt for an epidemiological study has so far failed to deliver a connection. Despite this, efforts to unveil the connection between the triggering of the immune system by adjuvants and the development of autoimmune conditions should be undertaken. Vaccinomics is a field that may bring to light novel customized, personalized treatment approaches in the future.