1. Pemphigus

2. an autoimmune mucocutaneous disease characterized by intraepithelial blister formation.
An autoimmiun reaction to intercellular
keratinocyte protein (desmoglein3)
This results from break down or loss of intercellular adhesion,…….
epithelial cell separation known as Acantholysis .

3. painful ulcers preceded by bullae.
the ocular lesions of pemphigus do not tend to produce scarring and symblepharon formation
The first signs appear in the oral mucosa in approximately 60% of cases.
Nikolsky`s sign +

5. the oral lesions …….."the first to show, and the last to go."

7. Histopathology
Intraepithelial clefting with keratinocyte acantholysis.
Loss of desmosomal attachments and retraction of tonofilaments result in free floating, or acantholytic, Tzanck cells.
Bullae are supra basal and basal layer remains attached to the basement membrane.

9. Confirmation of diagnosis by DIFexamination of fresh perilesional tissue or tissue submitted in Michel's solution.
IIF is also typically positive in 80% to 90% of cases ,