Sex: M
Vaccine: COVID19
Symptoms: Antibody test, Biopsy, Immunology test, Pemphigus, Physical examination
Clinical narrative: This is a literature report for the following literature source(s): "New-onset pemphigus vegetans and pemphigus foliaceus after SARS-CoV-2 vaccination: A report of 2 cases", JAAD Case Reports, 2022. A 25-year-old otherwise healthy man presented to the dermatology clinic with a 2-month history of an expanding, painful erythematous papule in his right axilla, which began 1 month after his second Pfizer mRNA BNT162b2 vaccination. Physical examination revealed a solitary macerated, erythematous to violaceous plaque with hyperkeratotic crust on the right axilla; no other mucocutaneous lesions were observed. Initial punch biopsy revealed dyskeratosis with a suprabasal epidermal split, brightly eosinophilic cytoplasm in keratinocytes, acantholysis, and prominent acanthosis. Given the isolated plaque on the axilla, the patient was initially given a diagnosis of benign familial pemphigus and was treated with clobetasol 0.05% ointment and intralesional injections of onabotulinum toxin, resulting in mild improvement. Six weeks after the initial evaluation, he developed flaccid blisters with erythematous rims scattered on the oral mucosa, face, trunk, genitals, and extremities. Direct immunofluorescence on a perilesional biopsy specimen revealed intercellular deposition of C3 and IgG on keratinocytes at all epidermal levels, with C3 mostly confined to the lower epidermis. Indirect immunofluorescence revealed elevated levels of IgG auto- antibodies against Desmoglein 1 (81 units/mL) and Desmoglein 3 (100 units/mL). Owing to the clinical findings of axillary lesions progressing to involve the trunk and face, in correlation with the initial biopsy revealing prominent acanthosis, the diagnosis was revised from benign familial pemphigus to PVeg, and the patient was started on oral prednisone (1 mg/kg/ d). Given a lack of clinical improvement at subsequent follow-up, the patient's prednisone dose was increased to 1.1 mg/kg/d, and adjuvant therapy with oral mycophenolate mofetil (1000 mg/d, up-titrated to 2500 mg/d over 6 weeks) was initiated. At the 6- month follow-up, the patient's blistering had ceased, and he was tolerating an ongoing steroid taper. Conclusion: New-onset pemphigus, including the less common variants PVeg and PF, may be associated with the administration of the Pfizer BNT162b2 and Moderna mRNA-1273 vaccines. In these 2 cases, patients successfully achieved remission of their pemphigus with treatment; however, the risk of disease relapse and optimal treatment regimen for vaccine-associated pemphigus remain unknown at this time. In addition, further research clarifying the relationship between messenger RNA SARS-CoV-2 vaccines and new-onset autoimmune diseases, including pemphigus, is warranted. Clinicians must weigh the benefits of vaccination given the severity of the ongoing COVID-19 pandemic against the risk, which may encompass new-onset pemphigus. Sender's Comments: As there is limited information in the case provided, the causal association between the reported event: "Pemphigus" and the suspect drug BNT162B2 cannot be excluded. The case will be reassessed once new information is available. The impact of this report on the benefit/risk profile of the Pfizer drug is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to Regulatory Authorities, Ethics Committees and Investigators, as appropriate.