Aphthous ulcers are self-limited, non-scarring, and recurrent, whereas MMP causes persistent, scarring erosions.
While causing oral and genital ulcers, the ulcers of Behcet's are typically "punched-out" and non-scarring, unlike the large, scarring erosions of MMP.
Mucositis from chemotherapy is an acute event directly related to drug administration, not a chronic, autoimmune blistering disease.
An FDE is a recurrent erosion in the exact same spot triggered by a drug, a different pattern than the progressive scarring of MMP.
Primary herpetic gingivostomatitis is an acute, self-limited viral infection, whereas MMP is a chronic autoimmune disease.
Neutropenic ulcers are associated with a low white blood cell count, a finding not inherent to MMP.
Pemphigus vulgaris also causes severe oral erosions, but it is an intraepidermal split, leading to more fragile, non-scarring blisters, whereas MMP is a subepidermal split that leads to significant scarring.
SJS is an acute, severe, widespread mucocutaneous reaction to a drug, whereas MMP is a chronic, slowly progressive disease.
The mucous patches of secondary syphilis are painless, greyish-white plaques, not the painful, raw erosions of MMP.
