haemorrhagic bullae in the oral mucosa with gingival bleeding

A 56 year old woman presented with a 2 day history of multiple painless violet haemorrhagic lesions on her gums, tongue, and buccal mucosa (fig 1⇓). This was associated with gingival bleeding, but there was no relevant medical history of comorbidity, medications, or local trauma. She was diagnosed with multiple haemorrhagic bullae. Blood tests done...