**5. Conclusions**

Nikolsky's sign is a simple nondiagnostic test that may suggest a need for biopsy diagnosis of autoimmune or other diseases in the oral mucosa. The gingiva is often a preferable site for performing the test for Nikolsky's sign especially if DG is present. A positive reaction of this sign is the basis for suspecting autoimmune bullous diseases such as MMP and PV. In that case, it is critical to conduct DIF testing in conjunction with histopathological examination to establish the final diagnosis. It is also important to remember that DG is a general descriptive term rather than a diagnosis. Oral healthcare providers have a great responsibility to remain suspicious of unexplained oral manifestations of systemic or unusual intraoral diseases and disorders. The presence of a positive oral Nikolsky's sign serves as a warning that careful evaluation is needed in search of the etiology of the sign. Once other causes have been eliminated, the clinician must remain aware that biopsy or referral for biopsy may be necessary to determine the current diagnosis. It is important to remember, however, that biopsy of tissue sites that feature Nikolsky's sign is not indicated because a positive Nikolsky's sign is indicative of friable epithelium and proper diagnosis is predicated on obtaining a biopsy from a site with intact epithelial surfaces. Nonetheless, this simple test for Nikolsky's sign may serve as a valuable indicator of underlying autoimmune or other diseases and lead to obtaining a correct diagnosis. In many instances patients with diseases or disorders featuring gingival Nikolsky's sign may require appropriate referral to other dental or medical specialists after identifying suspicious lesions. For the early diagnosis of autoimmune bullous disorders, oral healthcare providers should consider the use of this test that may ultimately lead to the early diagnosis of MMP and PV or other diseases or disorders.
