Generalized pustular psoriasis flare in a patient affected by plaque psoriasis after BNT162b2 mRNA COVID-19 vaccine, successfully treated with risankizumab.

Conflicts of interest

A. Narcisi has served on advisory boards, received honoraria for lectures and research grants from Almirall, Abbvie, Leo Pharma, Celgene, Eli Lilly, Janssen, Novartis, Sanofi‐Genzyme, Amgen and Boehringer Ingelheim. A. Costanzo has been consultant and/or speaker for AbbVie, Almirall, Amgen, Janssen, Leo Pharma, Eli Lilly, Galderma, Boehringer, Novartis, Pfizer, Sandoz and UCB; R.G. Borroni has been consultant for Almirall and speaker for Abbvie.

Funding sources

None.

Data availability statement

Additional data are available on request to the corresponding author.

Editor,

With the widespread use of COVID‐19 vaccines, several cutaneous adverse reactions are emerging, including flares of pre‐existing dermatoses , : we describe the case of a 47‐year‐old female patient, affected by plaque psoriasis since 2001, who presented to our Emergency Department with an exacerbation of psoriasis after the second dose of BNT162b2 COVID‐19 vaccine. The patient referred the rapid worsening of her psoriasis, starting from 10 days after the vaccination (Second dose inoculated on 23 May 2021). She was on treatment with ustekinumab 90 mg since 2016, and she skipped the scheduled administration in May 2021. She was also affected by obesity and psoriatic arthritis; she was previously treated with infliximab, discontinued for intolerance. On physical examination, we observed wide erythematous plaques confluent to both the trunk and the four limbs, covered by large scales. The PASI was 29.8 and the involved body surface was more than the 30% of the total area. She had fever (38.2 °C) and arthralgias; blood examinations showed 11 000/mm3 white cells, C‐reactive protein 14.56 mg/dL. After the hospitalization, blood cultures at the febrile peak returned negative; and 2 days later, we observed numerous small pustules surrounding the erythematous scaling plaques, although the pustular eruption was particularly intense on the cutaneous folds. The clinical appearance was suggestive for a flare of generalized pustular psoriasis (GPP) superimposed on a plaque psoriasis, and we supposed the relationship with the second shot of BNT162b2 COVID‐19 vaccine. During the hospitalization, the pustules became larger, coalescent and thicker, involving also patient’s palms and soles; few patches began to ulcerate and the scaly plaques involved also the face and the scalp (Figs. 1 and 2a,b). Tumour markers for malignancy were negative. Having considered the risk of a superimposed infection, the comorbidities and the severity of the psoriasis, we therefore decided to start therapy with risankizumab 75 mg/fl with two subcutaneous injections, while an oral therapy with daptomycin 850 mg/day was prescribed. One week after the first dose of risankizumab, the pustular eruption disappeared and after 2 weeks of hospitalization the plaques improved, with only slight erythema. She received the second dose of risankizumab and to date she is still on therapy, having achieved the complete disease control (PASI 0) at Week 16 (Fig. 2c).

Figure 1

GPP flare presenting in our 47‐year‐old patient: wide erythematous and scaly plaques surrounded by small non‐follicular pustules spreading on the abdomen, both legs and forearms. Scaly and hyperkeratotic plaques involving the face and the scalp.

Figure 2

Clinical presentation at the first access in our Emergency Department (a), at the baseline before starting treatment with risankizumab 75 mg/fl (b) and finally after 16 weeks (c): for each time point both the anterior and posterior surface of the body are shown.

Flare‐up of plaque psoriasis in the setting of SARS‐CoV2 infection and after COVID‐19 vaccines is widely described in literature, usually resolving after few weeks but, sometimes, needing rescue therapies. , , D. Pesqué et al. suggested a relevant role of COVID‐19 vaccines in the re‐activation of inflammatory pathways underlying a pre‐existing plaque psoriasis. B. Awada et al. hypothesized that COVID‐19 vaccination (or infection) may lead to an IFN‐I‐mediated immune response by stimulating the plasmacitoid dendritic cells. It has also been suggested the role of Sars‐CoV‐2 infection as a trigger to an IFN‐driven inflammatory disorder such as GPP in genetically susceptible individuals. D. Perna et al. also reported a GPP flare in a patient affected by plaque psoriasis who received the first dose of BNT162b2 vaccine, treated with acitretin. Regarding the therapy, we prescribed risankizumab, a IL‐23 inhibitor, since our patient was intolerant to infliximab, previously on optimal therapy with ustekinumab, affected by severe obesity and at risk of superimposed infections. In conclusion, we described GPP flare and exacerbation of psoriasis in a patient who previously received BNT162b2 vaccine: this could probably be a rare adverse reaction related to COVID‐19 vaccine, in a patient who interrupted the biological therapy. Since the high rate of comorbidities in psoriatic patients, the vaccination should be strongly recommended in this population. On the other hand, dermatologists should keep in mind the possibility of rare flare‐up of pre‐existing dermatoses or the onset of new cutaneous manifestations in genetically predisposed patients. No guidelines are currently available concerning the management of a GPP flare after COVID‐19 vaccine, and further cases should be collected to deepen our knowledge.