Eponymous dermatological signs in bullous dermatoses.

Clinical signs are evolved by clinicians through their careful clinical examination. Medical professionals are generally familiar with these signs because of the emphasis given to them by the teaching faculty while they were students. Some of these signs are eponymously named after the clinicians giving credit to their observation. Eponymous signs in vesiculobullous diseases such as Nikolsky sign and Asboe Hansen sign (Bulla spread sign) are well known and were described during the 19th and 20th century, respectively. Cerebriform tongue in pemphigus vegetans was described by Premalatha (1981) three decades ago and is well recognized and cited in several text books and articles in leading journals. All these signs are revisited below with an emphasis on cerebriform tongue in pemphigus vegetans which could eponymously be called as Premalatha sign.

What was known?

In vesiculo bullous diseases, clinical signs such as Asboe Hansen sign or “bulla spread sign” and Nikolsky sign are well known to us eponymously. Dermatologists are also aware of cerebriform tongue in pemphigus vegetans described by Premalatha.

Introduction

“Eponymous dermatological signs” are those that usually named after the astute dermatologists, who described the sign first or occasionally named after a famous patient in whom the sign was first described.

The eponymous signs are not coined by self or by the authors concerned. Initially, they are labeled based on the morpholology, simile or mechanism. These signs become “eponymous” in course of time when they are given importance and cited in standard text books and articles of reputed journals. They are also strikingly remembered by the members of the specialty concerned. For example, the finger pebbles- “Pebble sign” in diabetes mellitus based on the morphology is also called as “Huntley papules” or Huntley sign’ named after the author Huntley AC. “Bulla spreading sign” based on the “mechanism” has also become eponymous and called as “Asboe-Hansen sign” named after the author Asboe - Hansen.

The two old eponymous signs Nikolsky sign and Asboe-Hansen signs in Bullous dermatoses are revisited in this article.

In addition, “Cerebriform tongue”- a clinical sign in pemphigus vegetans also has been revisited.

This tongue sign in pemphigus vegetans first described by Premalatha was labeled as “cerebriform tongue” based on the morphology.

This sign has become eponymous nowadays, as it has been quoted in many standard major text books and articles of reputed journals following her first report of this clinical sign in 1981.[1234567891011]

Though the morphology and physical characteristics are important in these dermatologic signs, the eponymous nature of these signs highlights the richness of history of dermatology.[12]

Asboe-Hansen sign

This “bulla spread sign” refers to the extension of a blister to adjacent unblistered skin when pressure is put on the top of the bulla.[13] This sign is named after Gustav Asboe-Hansen (1917-1989), a Danish physician.[14] The Asboe-Hansen sign in fact could be considered as a variation of the bulla spread sign. It applies to smaller, intact, tense bullae where the pressure is applied to the center of the blister.

In the traditional “bulla spread” sign also called Lutz sign, the margin of an intact bulla is first marked by a pen. Slow and careful unidirectional pressure applied by a finger to the bulla causes the bulla to extend beyond the marked margin. While a regular rounded border is observed in bullous pemphigoid and other subepidermal blistering disorders irregular angulated border is seen in pemphigus vulgaris. The sign may also be elicited on a burst blister if an adequate portion of the roof is intact.[15]

The bulla spread sign is positive in all varieties of blistering diseases like the pemphigus group of diseases and many cases of subepidermal blisters, including bullous pemphigoid, dermatitis herpetiformis, epidermolysis bullosa acquisita, cicatricial pemphigoid, dystrophic epidermolysis bullosa, bullous drug eruptions, Stevens-Johnson syndrome and toxic epidermal necrolysis.

Both Asboe Hansen and Nikosky sign have been demonstrated in acute bullous lichen planus.[16] Due to fragility of the roof of the blister Asboe Hansen sign is usually negative in Hailey-Hailey disease and staphylococcal scalded skin syndrome.[15]

Asboe-Hansen is also eponymously remembered for Asboe-Hansen's syndrome, which is the initial phase of the Bloch-Sulzberger syndrome.

Nikolsky sign

This is a clinical dermatological sign, named after Pyotr Nikolsky, a Russian Physician (1858-1940). The sign is present when slight rubbing of the skin results in exfoliation of the outermost layer, forming a blister within minutes. The credit of the finding “Nikolsky sign” should also go to his teacher M.I. Stukovenkov (a Russian Dermatologist (1847-1897) who pointed out this observation in pemphigus foliaceus. However, the sign was well described by his brilliant student P.V. Nikolsky in his thesis and popularly came to be known as Nikolsky sign.

The sign indicates intra epidermal cleavage and can also be elicited on the mucosal surface. When the sign is elicited in the normal looking skin in the vicinity of the blister it is called marginal Nikolsky sign and if it is elicited away from the blister it is called direct Nikolsky sign. The sign also predicts the activity of the disease while on therapy.[15]

Nikolsky's sign is useful in differentiating pemphigus vulgaris (where it is present) from bullous pemphigoid (where it is absent). Also present in Scalded Skin Syndrome caused by the exfoliative toxin of Staphylococcus aureus.[17]

Pseudo Nikolsky sign or epidermal peeling sign is positive in Stevens-Johnson syndrome, toxic epidermal necrolysis, in some cases of burns and bullous ichthyosiform erythroderma. Although the method and mechanism of elicitation of the sign are the same as for Nikolsky sign, this could be elicited only in the involved erythematous areas, since the underlying pathology in these diseases is necrosis of the cells in contrast to acantholysis in pemphigus group.[15]

Premalatha sign

Cerebriform tongue showing the typical sulci and gyri pattern over the dorsum of the tongue is a characteristic clinical sign in pemphigus vegetans which can precede, coincide or follow the skin lesions of pemphigus vegetans.[1]

Out of 108 cases of pemphigus attended the skin department, Madras Medical College and Government General Hospital during the years 1968-1979, 12 cases were pemphigus vegetans proved by clinicopathological correlation. Six cases of Neumann type (50%) showed the characteristic tongue sign. Biopsy from the tongue lesions showed typical features of pemphigus vegetans.[1] Two of the cases also had “cerebriform scalp” and skin biopsy was consistent with pemphigus vegetans. The papillomatous hyperplasia present in pemphigus vegetans may be the cause for both cerebriform scalp and cerebriform tongue.[1]

The term “cerebriformt tongue” was coined by the author based on the morphology still holds good and self-explanatory. This sign first described by Premalatha has become eponymous also nowadays, as there are about 17 citations in the world literature, quoted both in the standard major text books and many articles of reputed journals, added to its awareness among the members of our speciality-“Dermatology” Recently published by Wiley Online Library also on 29th July 2006.

Conclusion

Clinical signs always give a clue to the probable/possible diagnosis of the disease in many conditions. These signs are evolved by the careful observation by good clinicians. Naming the signs after these clinicians is considered as a mark of recognition of their invaluable work in addition to creating a mark in the history of the specialty. Therefore, cerebriform tongue in pemphigus vegetans which has been accepted and cited by many authors world over should hither to be referred eponymously as “Premalatha sign.”

What is new?

Since cerebriform tongue described by Premalatha is yet another newer clinical sign in vesiculobullous diseases with many citations, her observation could be called eponymously after her name as Premalatha sign.