 This case study reports a patient who was diagnosed with autoimmune bullish disease, AIBD. The patient had IgG and IgM autoantibodies against the Epidermal Basement Membrane Zone, BMZ, which caused recurrent mucocutaneous lesions after being administered the COVID-19 mRNA vaccine. This is the first reported case of AIBD with IgG and IgM autoantibodies where the mucocutaneous lesions reappeared after receiving the vaccine. It is important for physicians to be aware of this potential risk when treating patients with AIBD. This article was authored by Satoko Minakawa, Satoko Minakawa, Yasushi Matsuzaki, and others.