Dermoscopy Saga - A Tale of 5 Centuries.

The origin of dermoscopy can be traced back to the middle of the modern age and Borel's discovery (1655 - 1656) laid the foundation stone with important contributions from Ernst Karl Abbe, Unna, Muller, Saphier and others. However, the work done by Dr. Ronald Mackie (1971) for the early detection of melanoma marks the peak. The entire journey of evolution was eventful. This article is a brief overview on the history of dermoscopy and the contribution of various scientists leading to emergence of dermoscopy as an independent, dynamic field today. Copyright:

History

The old technique of dermoscopy has come a long way since its inception for non invasive evaluation of dysplastic changes in suspicious nevi in susceptible individuals.Nowadays, its a necessary tool for dermatologists given the fact tat its scope has expanded not only in the diagnosis of non melanocytic disorders of skin, hair, and nails, but is being exploited rightfully for a myriad of non diagnostic uses.

The origin of dermoscopy dates back to the middle of the modern age, even before the emergence of Dermatology as a science. The basic principle of dermoscopy is transillumination of a lesion and studying it with a high magnification to visualize subtle features barely visible to the human eye.[1]

Origin

Pierre Borel (Borrelius Petrus, 1620–1689) was a doctor, botanist, and French alchemist and author of several publications “De vero telescopii inventore” in 1655 and “Observationum microscopicarum centuriae” in 1656 was a pioneer in the use of microscope. He was the first to use this technique to observe the capillaries of the nail bed under a microscope the first time the technique we now call “capillary dermoscopy” was used).[23456]

These observations were reproduced eight years later in 1663 by Johan Christophorus Kolhaus. After a gap of approximately 200 years, in 1879, Carl (Karl) Hueter, a German surgeon, reported his studies of the capillaries of the lower lip with the help of a magnifying glass and under artificial light.[78910]

In 1878, Ernst Karl Abbe, a German optometrist and physician, and author of several works on refraction along with Carl Zeiss, a manufacturer of microscopes, telescopes, and other optical systems, devised the application of cedar oil instead of water (based on studies conducted by Abbe refraction) to increase the resolution of microscopes. With this improved immersion microscopy, sharp, bright, and higher magnification images could be obtained[101112] [Figure 1].

Figure 1

Binocular microscope by saphier with lateral lighting sources for the evaluation of normal and diseased capillaries (published with permission of the journal: Dermatologia Revista Mexicana)[1]

Unna published a paper in 1893 entitled “Diaskopie” describing how immersion oil was used together with a microscope for skin surface microscopy.[13] He recognized that the upper layers of epidermis blocked light from entering the skin and determined that skin could be made more translucent with water soluble oils and other fluids.

From 1916 to 1920, several monocular and binocular capillary microscopes were built according to the plans of Muller [Figure 2]. Binocular instruments were based on an apparatus developed by Greenough in 1892, with two separate oculars and objectives positioned 14 degree from each other. With this instrument, the skin surface could be viewed at a magnification of 10–172×.

Figure 2

Mononuclear capillary microscopy for the examination of finger designed by Muller[18]. (Published with permission of Journal of Sociedade Portuguesa da Dermatologia e Venereologia)[6]

Saphier then published several papers from 1920 to 1921, in which the term dermatoskopie was used for the first time [Figure 2].[14151617] After several years in Vienna with Reihl, Saphier continued his work with Von Zumbusch at the Department of Dermatology, Ludwig Maximilian University, Munich. He discussed the applications of skin surface microscopy in dermatology in four contributions. He used a binocular microscope with a weak lateral illumination source in contrast to light diodes in modern dermoscope such as Dermogenius basic. Saphier applied dermoscopy predominantly for the evaluation of skin capillaries under normal and pathological conditions. He tried to establish the criteria for discriminating between cutaneous tuberculosis and syphilis, a matter of great importance at that time. He also carefully investigated the morphological basis of skin color which, according to Unna, was composed of two components: the diffuse color of the epidermis and the pigment aggregations in rete ridges that form the different structures. Although Saphier did not extensively investigate the differential diagnosis between benign and malignant melanocytic lesions, he did study melanocytic nevi and was the first to describe pigment cells, a term still used in our rankings. In 1922, dermoscopy was applied for the first time in the USA by Michael, a Houston dermatologist familiar with Saphier's work.

In 1911, Lombar was the first to report the use of glycerine to the nail fold capillaries to make them more visible. From 1911 until 1922, the internist Otfried Müller laid the foundation for the construction of various microscopes to observe capillaries [Figure 3]. Earlier in the 20th century, Lombard, Muller, Schur, and Weiss introduced the clinical technique of capillary microscope. The practical impact of capillary microscopy on internal medicine was initially small. One exception was in Meersburg, Germany, where in the 1920s capillary microscopy was routinely employed allegedly to detect cretinism in newborns. According to Jaensch, the promoter of this approach, defects in intelligence and growth were associated with atypical capillaries. In 1927, Bettmann tried to define different constitutional types with capillary microscopy in a hope to explain predisposing factors for certain skin diseases. Although theses hopes were not achieved in the skin, Hinselmann used the principles of skin surface microscopy as he developed colposcopy for the diagnosis of cervical diseases during the 1930s. Today capillary microscopy is most often used for early detection of capillary vascular changes in the nail fold in systemic connective tissue diseases.

Figure 3

Various types of hand held instruments for skin surface microscopy[20]. Published with permission of Journal of Sociedade Portuguesa da Dermatologia e Venereologia)[6]

In 1922, Jeffrey C Michael was the first to use this technique in USA.[19]

In the 1950s, Lean Goldman applied this technique to the evaluation of melanocytic nevi and melanoma.[202122] He also investigated numerous pigmented melanocytic nevi and malignant melanomas using several devices. His studies were hindered by the weak light source of his monocular equipment. [Figure 4]. From 1952 in Germany, Franz Ehring and colleagues worked intensively in the field of surface microscopy and introduced the term “vital histology of skin.” J. Schumann, a member of the research team of Ehring, also studied pigmented tumors in 1970.

Figure 4

Vunliffe article using the microscope laptop. (Published with permission of the journal : Dermatologia Revista Mexicana)[1]

In 1958 and subsequently, Gilje Cunliffe et al. described the utility of surface microscopy in various diseases, predominantly in inflammatory conditions [Figure 5].[2324252627]

Figure 5

Binocular microscope by Dr. Ronald Mackie. (Published with permission of the journal : Dermatologia Revista Mexicana)[1]

However, despite all previous contributions, a real turning point in the history of modern dermoscopy was when Dr. Ronald Mackie, a Scottish born in Dundee, in 1971 first described the advantage of using surface microscopy for the preoperative diagnosis of pigmented lesions, mainly melanocytic nevi, and differential diagnosis of melanoma using a Zeiss stereomicroscope [Figures 6 and 7].[2829]

Figure 6

Dermagenius. (Published with permission of the journal : Dermatologia Revista Mexicana)[1]

Figure 7

Zeiss 1865. (Published with permission of the journal : Dermatologia Revista Mexicana)[1]

In the 1980s, several authors including Fritsch and Pechlaner, Pehmberger et al., and Soyer et al., published articles on dermoscopy.

In 1990, Kreusch and Rassner developed a portable binocular stereomicroscope that was easy to use, comfortable to hold, and capable of magnifications of 10–40×. Despite these advances, all the equipment mentioned had the disadvantage of being either expensive, cumbersome, and/or time consuming to utilize. To overcome these difficulties, our group developed the hand-held dermoscope. Owing to this broader use, a rapid increase in publications in this field could be observed.

Many different terms have been used in the literature for this technique. The term “dermatoscopy” was first used by Saphier. Other terms used include surface microscopy (Soyer and colleagues), incident light microscopy (Fritsch and colleagues), and epiluminescence light microscopy (Pehamberger and colleagues). In 1991, Friedman and colleagues introduced the term “dermoscopy” for this technique, which is currently used in USA.

In 1989, a consensus conference was held by the Committee on Analytical Morphology in Hamburg, Germany, to develop a standardized terminology for this technique. The results of this Consensus were then published by Bahmer et al. in 1990.[3031] Throughout the 1990s, several groups developed different diagnostic methods for analyzing dermoscopic images. In an attempt to refine this technique, a Second Consensus Net Meeting on Dermoscopy was held. The goals of this Second Consensus Meeting were to further refine the definitions of dermoscopic structures and to “prove the validity of a 2 step procedure for dermoscopic classifications of pigmented skin lesions.” From July until November 2000, 40 participants from various countries evaluated dermoscopic images transmitted over the internet. A training set of 20 cases was reviewed by each member first as a tutorial. Then each member evaluated 108 pigmented skin lesions for the presence of various dermoscopic features. Each of the following four methods of analysis were used to make a diagnosis: (1) pattern analyses, (2) ABCD rule, (3) Menzies method, (4) seven-point checklist.[31] The results of the Consensus Net meeting on dermoscopy were then presented at the First World Congress of Dermoscopy in Rome in February, 2011. The many improvements in digital camera technology, especially the introduction of charged coupled devices, have made possible adequate resolution at an affordable price so that videodermoscopy becomes widely available. The rapid expansion of the internet and the amazing advances in computers have made teledermoscopy possible, facilitating consultation and exchange of images and information. Cascinelli and colleagues performed the first pilot study with computer-aided dermoscopic images using digital slides in the late 1980s.[32]

Trichoscopy is hair and scalp dermoscopy using a hand-held dermoscope or polarized light videodermoscope.[3334] Historically, in 1993, in Kossard and Zagarella described spotted white dots in cicatricial alopecia in dark skin as the first dermoscopic finding in hair loss diseases, but the method has gained popularity in recent years.[35] In 2004, Lacrubba et al. first described videodermoscopic features of alopecia areata.[36] In 2005 and 2006, Rudnicka and Olszewska first used videodermoscopy for the evaluation of disease severity in androgenetic alopecia and for monitoring treatment efficacy.[37] In 2006, Ross et al.[38] specified videodermoscopic features of different acquired hair and shaft disorders. In 2006, the term “trichoscopy” for hair and scalp videodermoscopy in hair loss diagnostics was first used.[39] In 2007, Rakowska et al. showed that trichoscopy can easily replace trichoscopic evaluation of pulled hair in genetic hair shaft abnormalities such as monilethrix.[40] Since then, several trichoscopic hair and scalp abnormalities have been described, and trichoscopic criteria for diagnosing female androgenetic alopecia have been developed.[41] The first atlas of dermoscopy of hair and scalp was published by Tosti in 2008.[42] Since then volumes of work has been published on trichoscopy of hair and shaft disorders in various skin types.

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