Covid‐19 dermatoses: Acral vesicular pattern evolving into bullous pemphigoid

Abstract

Bullous pemphigoid (BP) appears to be rising in incidence across the Western World, especially in the elderly. Some of the pathogenetic mechanisms involving antigen mimicry and antibody cross‐reactivity have been elucidated for cases associated with neurological disease and certain drugs. There have been reports of cutaneous manifestations of Covid‐19 (SARS‐Cov2 infection) as the pandemic has raged across the world. We report here a case of prolonged Covid‐19, symptomatic with dermatoses only, which was seen to evolve initially from a maculo‐papular exanthema with acral vesicular dermatitis, into classical BP disease. This was confirmed histologically by positive skin autoantibody serology, direct IMF on peri‐lesional skin and also salt‐split IMF. Although possible that the development of BP could be a purely co‐incidental finding during Covid‐19, we suggest that it is more likely that prolonged SARS‐Cov2 infection triggered an autoimmune response to the basement membrane antigens, BP 180 and 230. To our knowledge, this is the first case of BP developing during concurrent Covid‐19 disease. It will be necessary to continue dermatological surveillance as the pandemic continues, to collate data on BP incidence and to test these patients for Covid‐19 disease. As the pandemic continues, even potential and rare associations such as this will be clarified eventually.

New‐onset vitiligo following COVID‐19 disease

“…8 Indeed, molecular mimicry-induced autoimmunity has been described between SARS-CoV-2 antigens and hosttissue components. 4,12 Noteworthy, a case of bullous pemphigoid arising after COVID-19 infection has already been described after an initial acral vesicular eruption. It has been hypothesized that prolonged skin inflammation during initial viral exanthem may have damaged the basement membrane, rendering it susceptible to the host's immune recognition with subsequent development of autoantibodies.…”

“…It has been hypothesized that prolonged skin inflammation during initial viral exanthem may have damaged the basement membrane, rendering it susceptible to the host's immune recognition with subsequent development of autoantibodies. 12 However, it must be considered that the occurrence of vitiligo after COVID-19 infection might just be coincidental. Indeed, vitiligo has a high global prevalence (0.5%-2%) and has never been associated to COVID-19 disease before.…”

A systematic review of dermatologic manifestations among adult patients with COVID‐19 diagnosis

“…Consistent with our findings, newer publications have reported various morphologies of dermatoses related to COVID‐19 infection, even within the same patient. One COVID‐19‐positive patient was reported to have an evolving eruption which started out as a maculopapular exanthem with vesicular dermatitis on the acral surfaces, but weeks later, tense bullae consistent with classic bullous pemphigoid were developed 30 . The more recent reports documenting laboratory‐confirmed SARS‐CoV‐2 infection can be seen in Table 5 30–42 .…”

“…One COVID-19-positive patient was reported to have an evolving eruption which started out as a maculopapular exanthem with vesicular dermatitis on the acral surfaces, but weeks later, tense bullae consistent with classic bullous pemphigoid were developed. 30 The more recent reports documenting laboratory-confirmed SARS-CoV-2 infection can be seen in Table 5. [30][31][32][33][34][35][36][37][38][39][40][41][42] Although more reports have emerged, there is still limited evidence-based reports regarding the predictive prognosis and significance of timeline of these dermatologic signs.…”

“…30 The more recent reports documenting laboratory-confirmed SARS-CoV-2 infection can be seen in Table 5. [30][31][32][33][34][35][36][37][38][39][40][41][42] Although more reports have emerged, there is still limited evidence-based reports regarding the predictive prognosis and significance of timeline of these dermatologic signs.…”