Reply to 'Nail psoriasis: A rare mRNA COVID-19 vaccine reaction' by Lamberti A et al.

Dear Editor,

We have read with great interest the article recently published by Lamberti et al. reporting the case of a 45‐year‐old woman developing nail psoriasis following the vaccination for Covid‐19 with Pfizer mRNABNT162b2. Herein, we report our experience about the correlation between COVID‐19 vaccination and nail psoriasis. Particularly, we observed five cases (n = 3, 60.0% males) with a mean age 52.2 ± 9.4 years, developing nail psoriasis following COVID‐19 vaccination with Pfizer mRNABNT162b2 (n = 4, 80.0%) and Moderna mRNA‐1273 (n = 1, 20.0%) from February 2021 to May 2022 (Table 1). Particularly, three patients experienced a worsening of nail psoriasis [Nail Psoriasis Severity Index (NAPSI) at last follow‐up before vaccination: 2.7 ± 3.4], and two patients developed de novo nail psoriasis following the vaccination. Interestingly, the patients reported experiencing an exacerbation of both nail psoriasis and psoriasis of other sites (Table 1). Of note, one patient with plaque psoriasis undergoing treatment with apremilast experienced de novo nail psoriasis, whereas the other patient reporting de novo nail psoriasis had no previous psoriasis history and/or treatment. All the patients developed nail psoriasis exacerbation after the second dose of vaccine, with a mean time from the vaccination of 19.6 ± 3.6 days. As regards the severity of nail disease, mean NAPSI was 22.4 ± 7.1, with only one patient reporting toenails involvement. Topical corticosteroids and topical keratolytics were added to current therapy in one patient treated with secukinumab; methotrexate was prescribed in one patient, while biological therapy (both switch or first prescription) was administered in the remaining cases (Table 1).

Table 1

Nail Psoriasis flares after COVID‐19 vaccine

	Sex	Age	Vaccine/dose	Days	Psoriasis personal History	PASI a	NAPSI a	PASI b	NAPSI b	Toenails	Previous treatment	New treatment
1	M	55	mRNABNT162b2/2	19	Yes	4	4	8	13	No	None	MTX
2	F	47	mRNABNT162b2/2	17	No	0	0	11	25	No	None	Ixekizumab
3	M	66	mRNA‐1273/2	21	Yes	4	0	14	23	No	Apremilast	Ixekizumab
4	M	41	mRNABNT162b2/2	16	Yes	3	7	16	32	Yes	Adalimumab	Brodalumab
5	F	52	mRNABNT162b2/2	25	Yes	2	2	2	19	No	Secukinumab	Secukinumab + TCS and TK

Abbreviations: Dose, number of doses after which psoriasis flare occurred; F, female; M, Male; mRNA‐1273, Moderna mRNA‐1273; mRNABNT162b2, Pfizer mRNABNT162b2; NAPSI, Nail Psoriasis Severity Index score; PASI, Psoriasis Area Severity Index; TCS, Topical Corticosteroids; TK, topical keratolytics.

PASI and NAPSI at last follow‐up before the psoriasis flare.

PASI and NAPSI at presentation in our department following the psoriasis flare.

Several cutaneous adverse drug reactions have been reported following COVID‐19 vaccination with both mRNA and vector‐based vaccines. , , Fortunately, most of these are self‐limited or required minimal treatment. As regards the possibility of nail psoriasis exacerbation after vaccination, data from current literature are scant. However, nail involvement seems to be clinical evident several days after vaccination compared with cutaneous psoriasis flares.

Lamberti et al. experience and ours showed the possibility of nail psoriasis development following COVID‐19 vaccination. Furthermore, our case series reported that psoriasis exacerbation following COVID‐19 vaccine may also develop in patients already receiving biological treatments.

Although the exact pathway behind the reported psoriasis exacerbations after COVID‐19 vaccination is still not clarified, these may be related to a stimulation of Th‐1 and Th‐17 pathways, which are reported to be hyper‐activated in psoriatic skin lesions, induced by an increment of Th 17 and IL‐6 levels, caused by vaccination. ,

In conclusion, clinicians must keep in mind the possibility of nail psoriasis worsening after COVID‐19 vaccination, especially in the first two‐third weeks following vaccination. However, several treatments are available for nail psoriasis and all the patients who developed this condition following vaccines improved following treatment. Thus, vaccination should not be discouraged.

AUTHOR CONTRIBUTIONS

All authors read and approved the final version of the manuscript.

ACKNOWLEDGEMENT

The patients in this manuscript have given written informed consent to publication of their case details.

FUNDING INFORMATION

None.

CONFLICT OF INTEREST

The authors have no conflict of interest to report.