Using Nikolsky’s original definition strictly, his eponymous sign is the physical splitting of the epidermis creating an erosion (partial loss of the epidermis) following the application of a shearing force to the surface of the skin seen in pemphigus foliaceus.
However, with time the use of the sign has broadened to include other intraepidermal disorders including pemphigus vulgaris and it has been used to differentiate them from subepidermal disorders. Historically it was a useful clinical sign, but it is now superseded by modern immunohistochemistry and specific antibody testing as knowledge of skin disease has grown since the first description.
The term “pseudo Nikolsky” sign or “Nikolsky’s test” has been applied to Stevens-Johnson syndrome/toxic epidermal necrolysis where the full epidermis is involved but a shearing force propagates the blister.
Pyotr Vasilyevich Nikolskiy (1858-1940) was born in Usman, Russia. He was Professor of Dermatology at Warsaw University, Poland, and later head of Department of Dermatology and Venereology at North-Caucasian University, Rostov-on-Don, Russia.
His doctoral thesis published in 1896 reported that when rubbing the skin of patients with pemphigus foliaceus “the skin shows a weakening relationship and contact among its layers… on all surfaces even in places between lesions (blisters and excoriations) on the seemingly unaffected skin”. He strongly emphasised a distinction between pemphigus foliaceus and pemphigus vulgaris. Nikolskiy stated that the level of the split was unique to pemphigus foliaceus and that only this disease elicits a positive sign.
He credits his teacher, Professor Mikhail Ivanovich Stoukavenkow of the University of Kyiv, for first recognising the sign.
His name was spelt Nikolskiy but the term Nikolsky is commonly used.
There are three methods to elicit Nikolsky’s sign:
