DISCUSSION:
This is the third case of LP following COVID-19 vaccination. In line
with literature cases, the patient developing LP recrudescence after
COVID-19 vaccination was a woman in her late fifties and was
successfully treated only with topical therapy, as the first reported
literature case.3,4
Of note, LP has already been associated also to COVID-19 infection,
other viral infections and anti-viral vaccinations. HBV vaccination is
the most frequently associated to LP and the first reported one, in
1990, followed by influenza and herpes zoster
vaccines.3,6-8
LP and LDEs occur uncommonly after anti-viral vaccinations and, as in LP
cases after COVID-vaccine, mainly affect middle-aged women, reflecting
increased risk of autoimmunity in adult females.8
The pathogenesis of LP triggered by anti-viral vaccines is not fully
understood. Activated auto-cytotoxic CD8 T-lymphocytes induce basal
keratinocytes’ death, increase of inflammatory cytokines, as IL-5 and
IFN-γ, and finally LP.8
Regarding the specific case of COVID-19 vaccine, only three associated
LP cases, comprising ours, have been reported up to date. The
association must be therefore considered as possibly just casual.
However, the present case and the first literature case, evidenced LP
reactivation in patients with dormant LP, possibly triggered by the
vaccine. This supports the thesis that vaccine-induced immune
dysregulation may reactivate LP, if not completely induce it.
Indeed, it has been reported that the BNT162b2 vaccine induces
upregulation of Th1 response which increases the levels of IL-2, IFN-γ
and TNFα, commonly known for being inflammatory cytokines directly
involved in the pathogenesis of LP.1,9 However, the
possible mechanism underlying LP (re)activation after Pfizer-BiotNtech
COVID-19 vaccination is still widely unknown and needs to be further
investigated.
In conclusion, it is important to stress that LP lesions, reported in
association with COVID-19 vaccination, are benign, successfully cured
with topical therapy and do not represent by any means a reason not to
undergo COVID-19 vaccination. Nonetheless, dermatologist should be aware
of this and all other possible cutaneous reactions associated to
COVID-19 vaccines, to promptly recognize and, if needed, treat them,
minimizing the patients’ discomfort and thereby encouraging the
population to undergo vaccination.10 Lastly, we
highlight the importance of reporting adverse reactions, in order to
promote vaccine safety through pharmacovigilance systems.
A cknowledgement:
The authors have no
acknowledgements to declare.