The first case report of Pityriasis lichenoides chronica following COVID-19 mRNA vaccination

Pityriasis following COVID-19 vaccinations: a systematic review

In the wake of a global COVID-19 pandemic, where innovations in vaccination technology and the speed of development and distribution have been unprecedented, a wide variety of post-vaccination cutaneous reactions have surfaced. However, there has not been a systematic review that investigates pityriasis eruptions and the associated variants following COVID-19 inoculations. A PubMed search using Preferred Reporting Items for Systematic Reviews and Meta-Analyses was performed to find case reports from the earliest record through November 2022. Data including types of vaccination and pityriasis were extracted and a quality review was performed; 47 reports with 94 patients were found: 64.9% had pityriasis rosea (PR), 3.2% PR-like eruptions, 16.0% pityriasis rubra pilaris, 7.4% pityriasis lichenoides et varioliformis acuta, 3.2% pityriasis lichenoides chronica, and 5.3% had reactions described as atypical. The top three COVID-19 vaccinations reported were Pfizer-BioNTech (47.9%), Oxford-AstraZeneca (11.7%), and Moderna (8.5%). Pityriasis reactivity was reported most frequently after the Pfizer-BioNTech vaccination, with pityriasis rosea being the most common variant. A large difference was additionally found between the ratio of post-vaccination pityriasis reactions following Pfizer and Moderna vaccinations (5.63), and the ratio of Pfizer's usage in the United States as of December 28, 2022 relative to that of Moderna (1.59). Further studies with adequate follow-up periods and diagnostic testing will thus need to be performed to elucidate the root of this discrepancy and better characterize the association between different pityriasis reactions and COVID-19 vaccinations.

Pityriasis Lichenoides Following SARS-CoV-2 Infection/Vaccination

Purpose of Review

Pityriasis lichenoides (PL) is a spectrum of dermatological conditions involving polymorphous lesions. Natural history of the condition ranges from acute to chronic. Cases of PL following SARS-CoV-2 infection/vaccination have been reported, but not yet comprehensively reviewed. Hence, the objective of this article is to review and summarize cases of PL following SARS-CoV-2 infection/vaccination in order to guide clinicians in its diagnosis and management.

Recent Findings

PubMed, Embase, and Web of Science were searched for relevant articles. Thirteen articles, consisting of 14 cases of PL following SARS-CoV-2 infection/vaccination, were identified. Males represented 64.3% of cases, and the average age of those affected was 41.4 years. The majority of cases (N = 9, 64.3%) were following SARS-CoV-2 vaccination, the most commonly implicated being Pfizer-BioNTech (n = 8/10, 80%), while four (28.6) followed infection. The overall latency period ranged from 5 days to 1 month. Treatments varied greatly. However, at the time of follow-up, 12/14 patients (85.7%) had either marked improvement or complete resolution of lesions.

Summary

This review cannot determine causality. However, a temporal association was observed with the case reports, and one case of PL followed SARS-CoV-2 infection and recurred with subsequent vaccination, suggesting an association. Nevertheless, risk of developing PL following SARS-CoV-2 infection/vaccination is likely extremely low. There is also the possibility these cases are purely coincidental. Still, clinicians should be aware of this possible etiology when diagnosing a new or exacerbated case of PL. Finally, given that the majority of patients had marked improvement or complete resolution of lesions at the time of follow-up, clinicians should provide reassurance to their affected patients.

Pityriasis Lichenoides et Varioliformis Acuta as a Complication of COVID-19 Infection

Pityriasis lichenoides is an acute and/or chronic skin disease associated with recurrent erythematous papules that self-resolve. While its etiology is unknown, preceding viral infection may play a role. We present an atypical case of a 40-year-old woman with pityriasis lichenoides et varioliformis acuta as a complication of a COVID-19 infection.