Immunization against COVID-19 and its relationship with the development of dermatological lesions: a case report of lichen planus.

Abstract

Introduction: Lichen planus is an inflammatory dermatitis that affects middle-aged adults, presenting as violet papules on areas such as wrists and neck. Its etiology is unclear, but cross-reactivity between antigens triggered by various causes is suggested. Association of hyperinflammatory reactions with SARS-CoV-2 is proposed, demonstrating LP-Like lesions. The presence of eosinophils and paraquetosis guides the diagnosis of lichenoid eruptions, indistinguishable from lichen planus. Theories regarding the relationship between COVID-19 vaccine and autoimmune dermatoses include cross-reactivity and genetic predisposition. Involved vaccines, especially Pfizer, may trigger immunological responses associated with autoimmune disorders. The temporal appearance of bullous diseases suggests a potential causal link with COVID-19 vaccination.

General objective: To establish, through the presentation of a clinical case, the relationship between the immune response induced by COVID-19 immunization and the subsequent development of lichen planus.

Specific objectives: 1) Describe the immunological processes involved in the pathogenesis of lichen planus. 2) Identify potential vaccines associated with the onset of the dermatological condition.

Materials and methods: Through the histopathological examination confirming the diagnosis, authorization was obtained from the health unit for analysis and publication.

Results: Lichen planus is an inflammatory skin disease linked to COVID-19 vaccine administration in documented cases worldwide. Reactions manifest with typical features like pruritic papules on arms, trunk, and lower extremities. Molecular mimicry is proposed, wherein a viral epitope triggers immune responses in keratinocytes. While most lichen planus cases lack known triggers, some are associated with antiviral vaccines, including hepatitis B. The temporal sequence, around 4 weeks between vaccination and dermatosis, supports a potential causal link between the SARS-CoV-2 inactivated vaccine and observed lichen planus in the patient.

Conclusions: The SARS-CoV-2 vaccine can trigger reactions in various tissues, as observed in the presented case with skin lesions resembling lichen planus. Emphasizing the importance of documenting vaccination history in dermatological assessments to prevent misinterpretations and recognize cutaneous side effects