This study had some limitations. First, although most of
the included studies were case reports with detailed docu-
mentation of patients’ clinical conditions, some of the stud-
ies were observational studies or data from retrospective
database collection that lacked detailed information. Some
of the results, including vaccine doses, other triggers, labo-
ratory studies, treatments, and disease outcomes, were not
reported by all studies, which prevented the determination
of any causal relationships between COVID-19 vaccines and
psoriasis. Second, severity scores, such as the PASI score,
NAPSI score, and BSA scale, are important parameters for
evaluating disease severity in psoriasis patients; however,
severity assessments were only reported in a limited num-
ber of studies. Detailed documentation of psoriasis disease
severity at pre-vaccination, post-vaccination, and post-treat-
ment time points is warranted in further studies. Third, a
limited number of cases reported whether the patient con-
tinued to receive vaccine doses in cases in which psoriasis
developed after the first dose, and reactions to later vac-
cines were rarely reported. Omicron, the new SARS-CoV-2
variant, has recently spread worldwide, and the necessity
of a third vaccine dose has been widely discussed [85, 86].
Various governments have promoted the administration of
a third booster vaccine dose to achieve better coverage and
protect against Omicron-mediated COVID-19 infection [87].
In the current study, only three cases with psoriasis flares
were reported following a third vaccine dose in the included
studies. Long-term follow-up of all patients who develop
psoriasis after vaccination and detailed documentation of
CAEs after the third COVID-19 vaccine dose are crucial
for exploring the relationship between COVID-19 vaccines
and psoriasis onset.