Meyerson nevus triggered by COVID-19

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Multiple cutaneous manifestations caused by COVID-19 have been described. However, its pathogenesis remains unclear. They have been attributed to an inflammatory mechanism, due to an immune response against viral nucleotides, and to a vascular mechanism, secondary to vasculitis or thrombosis. 2 After a rigorous search of the lit-ଝ Study conducted at the Department of Dermatology, University Hospital of León, León, Spain. erature, the authors did not find any case of Meyerson's nevus associated with COVID-19 infection or vaccination.
The authors present the case of a 34-year-old man with no medical history of interest who presented to the dermatology department with erythematous-squamous lesions and crusting over approximately half of his melanocytic nevi on the trunk (Fig. 1A). Visualization of dermoscopic structures was difficult due to the presence of serous crusting, slight whitish scaling, and an erythematous halo (Fig. 1B). The previous ten days he had suffered an uncomplicated upper respiratory tract infection due to COVID-19. The patient had not experienced similar lesions after SARS-CoV-2 vaccination or after previous infectious processes. Nor had he introduced any new drugs.
A biopsy of one of the lesions revealed nevus cells arranged in small thecae with adequate maturation without signs of dysplasia, surrounded by lymphocyte-predominant inflammatory infiltrate (55% CD4+, 45% CD8+) and marked spongiosis (Fig. 2).
It was diagnosed as Meyerson nevus triggered by COVID-19 infection. The lesions resolved after topical corticosteroid treatment (methylprednisolone acetate once daily for two weeks) and have not recurred to date. The affected nevi show a typical pigmented reticular pattern at present.
As for nevocentric dermatoses in relation to SARS-CoV-2, a case of nevocentric erythema multiforme three days  This mechanism has been associated with the development of different autoimmune processes triggered by viruses and could explain the development of a Meyerson nevus coinciding with COVID-19 infection.
In conclusion, COVID-19 infection, through a mechanism mediated by ICAM-1 and interferon, could trigger Meyerson's nevus. The authors encourage the reporting of this type of skin reaction in order to consider their inclusion among the possible cutaneous manifestations related to  Financial support None declared.

Authors' contributions
Rubén Linares-Navarro: Approval of the final version of the manuscript; critical literature review; data collection, analysis, and interpretation; effective participation in research orientation; intellectual participation in propaedeutic and/or therapeutic; management of studied cases; manuscript critical review; preparation and writing of the manuscript; study conception and planning.
Pedro Sánchez-Sambucety: Approval of the final version of the manuscript; critical literature review; data collection, analysis, and interpretation; effective participation in research orientation; intellectual participation in propaedeutic and/or therapeutic; management of studied cases; manuscript critical review; preparation and writing of the manuscript; study conception and planning.
Manuel Ángel Rodríguez-Prieto: Approval of the final version of the manuscript; critical literature review; data collection, analysis, and interpretation; effective participation in research orientation; intellectual participation in propaedeutic and/or therapeutic; management of studied cases; manuscript critical review; preparation and writing of the manuscript; study conception and planning.

Dear Editor,
A 33-year-old male patient presented with multiple erythematous-brown papules measuring 1 to 5 mm, disseminated on the upper limbs, trunk and thighs (Fig. 1). Dermoscopy disclosed the presence of a peripheral network and a central homogeneous pink area (Fig. 2). The condition had started two years before when he sought another Service and received a diagnosis of secondary syphilis, confirmed by non-treponemal (VDRL 1:64) and treponemal tests (positive FTA-ABS). He was treated on two occasions with three doses of benzathine penicillin, with no improvement of the skin condition (VDRL after treatments -1:16). Diagnostic hypotheses were made of generalized multinucleate cell angiohistiocytoma (MCA) and eruptive dermatofibromas.
Histopathology showed proliferated capillary vessels with dilated lumen (Fig. 3A)  cells with ample cytoplasm interspersed with fibroblasts, lymphocytes, and histiocytes (Figs. 3B and 3C). Immunohistochemical analysis showed: immunoexpression of CD138 in the cytoplasmic membrane of the interstitial plasmocytes that permeated the lymphoid aggregates (Fig. 4A); cytoplasmic immunoexpression of Factor XIIIa in spiky multinucleate giant cells (Fig. 4B); positive expression of CD68 and CD163 in dermal histiocytes and negative in endothelial cells; CD31 positivity in the vascular component and negative immunoexpression of S100, establishing the diagnosis of MCA.
After he was instructed about the condition, the patient chose not to undergo treatment for aesthetic purposes and returned after one year with spontaneous significant improvement in the number, pigmentation, and size of the lesions (Fig. 5).

Discussion
Multinucleate cell angiohistiocytoma is a rare benign fibrous histiocytic proliferation, described in 1985. 1 It often presents as well-circumscribed, dome-shaped erythematous-brown papules clustered on the hands, wrists, face, or legs. Localized, multifocal and generalized variants have been described, with the localized variant being the most common. Approximately 150 reported cases were