What Is Hand, Foot, and Mouth Disease (HFM)? Hand, foot, and mouth disease (HFM) is a common viral infection that causes painful red blisters in the mouth and throat, and on the hands, feet, and ...

Erythema multiforme is an immune-mediated skin condition that may develop inside the mouth. Oral symptoms can include lesions on the lips and blisters and erosions on the gums and palate.

If it occurs along the maxillary nerve, blisters can develop on the palate and gums of the upper teeth. In addition to the interior of the mouth, it is not uncommon for blisters to form on the ...