key: cord-0898914-o00vkpik authors: Essam, Reham; Ehab, Rana; Al‐Razzaz, Radwa; Khater, Maha W.; Moustafa, Emad A. title: Alopecia areata after ChAdOx1 nCoV‐19 vaccine (Oxford/AstraZeneca): a potential triggering factor? date: 2021-09-24 journal: J Cosmet Dermatol DOI: 10.1111/jocd.14459 sha: c2a42af7616eb99cde4d2b5d40951810050ee3a8 doc_id: 898914 cord_uid: o00vkpik nan In June 2021, a 32-year-old female patient attended our outpatient clinic with a complaint of a hairless patch involving the scalp that suddenly appeared 2 days ago. According to the history, the patient was vaccinated against SARS-CoV2 few days before the appearance of the lesion, and the patient did not complain of any associated systemic symptoms. She reported no other underlying diseases except for a previous controlled mild attack of AA followed by disease stability for 6 years. She also reported a pervious COVID attack one year ago. No family history for AA was present or history of any drug intake. Physical examination revealed a sharply demarcated patchy hair loss on the scalp without any scarring or scaling. General examination revealed no other associated cutaneous or systemic abnormalities. KOH examination was negative for fungal infection. Our provisional diagnosis was AA. Trichoscopic examination showed black dots, broken hairs, and newly growing hairs with some exclamation mark hairs (Figure 1 ). Laboratory investigations including liver, kidney, thyroid functions, anti-thyroid antibodies, and antinuclear antibody (ANA) test were within normal limits. Molecular mimicry is a well-established mechanism that could contribute to autoimmunity associated with a wide variety of viruses. The antibody-mediated response against viruses may cross-react with self-antigens, possibly leading to autoimmune diseases. Current data describe SARS-CoV-2 to be an additional virus that has molecular mimicry with humans. 3 Mechanism of action of the ChAdOx1 nCov-19 vaccine includes a modified version of a chimpanzee adenovirus, known as ChAdOx1 that has the ability to insert artificial DNA into human cells. The objective is to generate the synthesis of SARS-CoV-2 spike protein by the host cells, which will lead to activation of immune cells. 4 The ex- In conclusion, ChAdOx1 nCoV-19 vaccine (Oxford/AstraZeneca) was found to be safe and efficacious against symptomatic COVID-19 in large randomized controlled trials, but our report suggests its possible role in triggering AA in genetically predisposed patients through immune-mediated mechanisms. ChAdOx1 nCoV-19 vaccine, COVID-19, hair falling, SARS-CoV-2 No funding sources. A written consent was taken from the patient. Authors declare human ethics approval was not needed for this study. No conflict of interest. Essam R. and Moustafa EA conceptualized and designed the work. Essam R., Ehab R., and Al-Razzaz R drafted the manuscript. Essam R., Moustafa EA., and Khater MW revised the manuscript. All authors contributed to acquisition, analysis, and interpretation of data, gave final approval of the manuscript, and agree to be accountable for all aspects of work ensuring integrity and accuracy. Data is available upon request. F I G U R E 1 (A) Sharply demarcated bald patch on the scalp. (B &C) Trichoscopic examination showing black dots (blue circle), broken hairs (yellow asterisk), newly growing hairs (green square), and exclamation mark hairs (red arrows) F I G U R E 2 Suggested mechanism of autoimmune-mediated alopecia areata following COVID-19 vaccine 3,4,7 : The existence of molecular mimicry between the vaccine-induced proteins of SARS-CoV-2 and human components might give rise to pathological autoantibodies. Adjuvants may have a role in the production of these autoantibodies. (Created with BioRender.com) Cutaneous adverse effects of the available COVID-19 vaccines New onset of alopecia areata in a patient with SARS-CoV-2 infection: Possible pathogenetic correlations? Perspectives on vaccine induced thrombotic thrombocytopenia Molecular mimicry between sars-cov-2 spike glycoprotein and mammalian proteomes: implications for the vaccine Alopecia areata after vaccination: recurrence with rechallenge Hair loss after routine immunizations Autoimmune/inflammatory syndrome induced by adjuvants (ASIA) 2013: Unveiling the pathogenic, clinical and diagnostic aspects