UCSF

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.