Nikolsky's Sign

Posted by Elaine Moore Oct 29, 2006

Some autoimmune skin disorders are characterized by a condition of acantholysis, which is a loss of the normal adhesion of epithelial cells within the skin. This loss of adhesiveness prevents the skin cells from connecting. Acantholysis results in a blistering of the skin typically seen in the pemphigus and pemphigoid disorders. Because blistering may have other causes, diagnosis can be difficult. Nikolsky's sign is a clinical sign used to help differentiate some of the autoimmune skin disorders from one another. Nikolsky's sign can even be used to determine the prognosis of existing conditions.

The Russian dermatologist Pyotr Valilyewich Nikolsky first described Nikolsky's sign in 1896 in his thesis on pemphigus disorders. He initially described this sign as appearing after rubbing the skin of patients with pemphigus foliaceus, which caused a blistering or denudation of the epidermis with a glistening, moist surface underneath. The reason for this reaction, Nikolsky explained, was a weakening relationship and contact between the corneal (horny) and granular layers on all surfaces, even in places between lesions on seemingly unaffected skin. Nikolsky's observations were later confirmed in 1956 by the physician Lyell, who observed similar findings in patients with toxic epidermal necrolysis.

Use of Nikolsky's Sign Today

Although Nikolsky originally thought the sign only occurred in pemphigus foliaceus, later studies showed a positive response in all of the pemphigus disorders. Today, Nikolsky's sign is used to diagnose pemphigus. Pressure is applied with a finger or paperclip to the blistered skin, perilesional skin or normal skin in patients suspected of having pemphigus. A positive response, which can be very painful, is noted when there is extension of the blister and/or removal of the epidermis in the area immediately surrounding the blister or lesion. Nikolsky's sign is intended to be used on skin. However, there are reports of positive signs occurring on mucous membrane lesions, including esophageal blisters and erosions occurring on the cervical mucosa.

Nikolsky's sign is particularly useful in differentiating pemphigus vulgaris, which causes a positive sign, from bullous pemphigoid, in which the sign is usually absent. In one study, however, 13 percent of patients with bullous pemphigoid demonstrated a positive Nikolsky's sign. The sign has also been reported in toxic epidermal necrolysis, staphylococcal scalded skin syndrome, bullous impetigo, and epidermolysis bullosa. Nikolsky's sign is also seen in drug-induced pemphigus vulgaris.

In terms of prognosis, a wet or glistening Nikolsky's sign indicates active pemphigus disease. A dry base of eroded skin in the Nikolsky's sign is considered a dry sign and may indicate a regrowth of epithelial tissue, which could be considered a sign of healing or a favorable sign.

The true value of Nikolsky's sign is in differentiating internal causes of blistering, such as the autoimmune process in pemphigus, from localized, self-limiting, or external causes of bullous skin disease.

Resource:

Frank Urbano, Nikolsky's Sign in Autoimmune Skin Disorders, Review of Clinical Signs, Hospital Physician, January 2001.