Cutaneous findings following COVID‐19 vaccination: review of world literature and own experience

Abstract

There is growing evidence that not only the novel coronavirus disease (COVID‐19) but also the COVID‐19 vaccines can cause a variety of skin reactions. In this review article, we provide a brief overview on cutaneous findings that have been observed since the emerging mass COVID‐19 vaccination campaigns all over the world. Unspecific injection‐site reactions very early occurring after the vaccination are most frequent. Type I hypersensitivity reactions (e.g. urticaria, angio‐oedema and anaphylaxis) likely due to allergy to ingredients may rarely occur but can be severe. Type IV hypersensitivity reactions may be observed, including delayed large local skin lesions (“COVID arm”), inflammatory reactions in dermal filler or previous radiation sites or even old BCG scars, and more commonly morbilliform and erythema multiforme‐like rashes. Autoimmune‐mediated skin findings after COVID‐19 vaccination include leucocytoclastic vasculitis, lupus erythematosus and immune thrombocytopenia. Functional angiopathies (chilblain‐like lesions, erythromelalgia) may also be observed. Pityriasis rosea‐like rashes and reactivation of herpes zoster have also been reported after COVID‐19 vaccination. In conclusion, there are numerous cutaneous reaction patterns that may occur following COVID‐19 vaccination, whereby many of these skin findings are of immunological/autoimmunological nature. Importantly, molecular mimicry exists between SARS‐CoV‐2 (e.g. the spike‐protein sequences used to design the vaccines) and human components and may thus explain some COVID‐19 pathologies as well as adverse skin reactions to COVID‐19 vaccinations.

Bullous pemphigoid after SARS‐CoV‐2 vaccination: spike‐protein‐directed immunofluorescence confocal microscopy and T‐cell‐receptor studies

“…Dear Editor , Growing evidence suggests that SARS‐CoV‐2 vaccination is associated with a variety of cutaneous reactions. These include autoimmune‐mediated conditions such as autoimmune blistering diseases (AIBDs), one of which is bullous pemphigoid (BP) 1,2 . We report new‐onset BP in two patients following their first SARS‐CoV‐2 vaccination.…”

Palmoplantar lichenoid drug eruption following the administration of Pfizer-BioNTech COVID-19 vaccine

“…In this setting, type I hypersensitivity reactions (eg, urticaria, angioedema, and anaphylaxis) and type IV hypersensitivity reactions (eg, inflammatory reactions in the injection site, morbilliform and erythema multiforme-like rashes) are the ones more commonly observed. 10 Generally, the key initiating event that leads to the development of postimmunization LDE is not well understood. LDE (as well as LP) is characterized by persistently activated CD8 1 autocytotoxic T lymphocytes against epidermal cells 6 ; the lymphocytes can induce apoptosis of basal keratinocytes, generating various cytokines (eg, interferon gamma, interleukin 2) in order to enhance the expression of class II major histocompatibility complex molecules and antigen presentation to CD4 1 T cells.…”

“…6 Specifically, COVID-19 vaccines elicit a helper T cell type 1 response, increasing the serum levels of the abovementioned cytokines and inducing a lichenoid eruption, by a mechanism of molecular mimicry caused by genetic similarities of SARS-COV-2 spike protein components to endogenous crossreactive human antigens. 10 Topical steroids are the first-line treatment for both LP and LDE, in addition to the suspension of the causative drug for LDE. For patients in whom corticosteroid treatment has failed, who relapse after corticosteroid therapy, or who have contraindications to corticosteroids, acitretin may be considered a potential second-line therapy.…”

Reproducible leukocytoclastic vasculitis following severe acute respiratory syndrome coronavirus 2 vaccination

“…Similar to the natural COVID-19 infection, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines appear to have also the potential to induce a broad spectrum of cutaneous adverse events. 1 We report a 47-year-old male who noticed aggregated reddish spots on his ankles occurring approximately 3 days after his first Comirnaty ® vaccination. During the following next 2 weeks, the skin lesions completely resolved without any treatment.…”