I'll never get another covid vaccine.. it gave me psoriasis. this is from a study on the national institute of health. COVID-19 vaccination may be a triggering factor for psoriasis, indicated by the short intervals between vaccination and psoriasis onset in the absence of other significant factors. The potential for vaccines to trigger psoriasis has previously been suggested for other vaccines, including influenza, rubella, Bacillus Calmette-Guerin (BCG), tetanus-diphtheria, and pneumococcal polysaccharide vaccines [
50,
64–
67]. The development of psoriatic skin lesions involves various mechanisms. Koebner phenomenon, a characteristic development associated with psoriatic skin lesions, may occur at the site of skin injury associated with vaccination. IL-6 can be induced by various components, such as mycobacterial heat shock proteins, and the diphtheria toxoid present in BCG, tetanus-diphtheria, and influenza vaccines has been linked to the production of Th17 cells, which can further aggravate psoriasis [
65,
66]. In our study, no specific vaccine type was associated with a higher rate of new-onset psoriasis, but a large number of psoriasis flares was found after mRNA vaccines, including the Moderna and BioNTech/Pfizer vaccines. The most commonly administered COVID-19 vaccines rely on adenovirus vectors, mRNA, or virus-related proteins, which can trigger Th1 and Th17 responses [
1,
50]. The increased production of TNF-α and type I interferon (IFN-I) by CD4+ T cells and plasmacytoid dendritic cells (pDC) may also play roles in psoriasis activation [
68–
70]. We found that a large number of patients (23%) experienced psoriasis flares following the second vaccine dose. In addition, three patients in the new-onset group (9%) and seven patients in the flare group (3%) experienced psoriasis episodes after both the first and second vaccine doses. Only one patient in the new-onset group (3%) and six patients in the flare group (2%) experienced psoriasis events after the first vaccine dose but not after the second vaccine dose. However, we could not define any specific factors able to predict the occurrence of a psoriasis event due to a lack of detailed information provided by many articles. Further controlled studies are warranted to unravel the relationship between COVID-19 vaccines and psoriasis, including identifying the potential underlying immunologic reactions.
