Halo Nevi After Covid-19 Vaccination: Molecular Mimicry Attributed Cutaneous Side-Effect?

Abstract

Covid-19 vaccination is a crucial component of the public health response to reduce the spread of Covid-19. Although well-tolerated, Covid-19 vaccination is associated with several cutaneous adverse reactions. Here, we document a case of a young man who developed numerous halo nevi at sites of pre-existing nevi following Covid-19 vaccination. Our patient is a 21-year-old male who presented to clinic after noticing a recent change in his moles. Three months after receiving the Johnson & Johnson (J&J) Covid-19 vaccine, the patient reported that he developed a ring of “vitiligo” surrounding each of his existing moles. He also received the Moderna Covid-19 booster 8 months after receiving the J&J vaccine and contracted Covid-19 two months later, with no additional change in his moles. The patient was otherwise well with no past medical or family medical history of skin cancer. On examination, the patient was found to have numerous halo nevi that had developed at sites of pre-existing nevi and were distributed over his face, neck, trunk, and extremities. Examination of his scalp revealed patches of white hair, underneath which were additional halo nevi. The development of vitiligo in the setting of Covid-19 vaccination is thought to be related to the activation of autoimmunity. Autoimmunity secondary to Covid-19 vaccination may be the cause of this patient’s halo nevi, given the patient’s age and absence of any systemic symptoms.