1
The History of Onychomycosis

Bárður Sigurgeirsson

Department of Dermatology, Faculty of Medicine, University of Iceland, Reykjavík, Iceland

1.1 Introduction

The modern history of medical mycology is relatively short (Table 1.1). It was Agostino Bassi (1773–1856) who in 1836 described the muscardine disease of silkworms which was caused by a fungus that would be named eventually Beauveria bassiana in his honor [1]. The clinical aspects of dermatomycoses have been known for a much longer time. Aulus Cornelius Celsus (c. 25 BC to c. 50 AD) recognized inflammatory tinea and described the first kerion celsi, a name still used today [2]. At that time, no microscopic knowledge existed and therefore the study of diseases was purely based on clinical findings. Favus and sycosis were already known in ancient times (the word means tinea in Egyptian).

Table 1.1 Early development of medical mycology and onychomycosis.

Year

Author

Comment

References

1835

Bassi

Discovers that muscardine disease of silkworms is caused by a fungus

[1]

1837

Remak

Observes microscopic structures appearing as rods and buds in crusts from favic lesions. Does not publish his observations, but allows his findings to be cited in a doctoral thesis of Xavier Hube

Not published [3]

1839

Schönlein

Communicates the fungal nature of dermatomycoses

[4]

1841–1844

Gruby

Unware of Remek’s and Schönlein’s findings, he describes clinical and microscopic characteristics of the causative agent of favus

[5–8]

1853

Meissner

Discovers that onychomycosis is caused by fungi

[9]

1854

Virchow

First to use the name onychomycosis for this new disease

[10]

Johannes Schönlein was the first to understand the fungal nature of dermatomycoses [4]. Sabouraud began his scientific studies of the dermatophytes around 1890, culminating in the publication of his classic volume, Les Teignes, in 1910 [11]. No specific antifungal drugs existed until after World War II.

1.2 The History and Discovery of Onychomycosis

A German medical student, Georg Meissner (19 November 1829 to 30 March, 1905) was the first to describe the fungal nature of onychomycosis in 1853 (Figure 1.1) [9]. It was Meissner later who became famous for discovering the tactile instrument of the skin (Meissner’s corpuscle). Meissner described accurately both the clinical and mycological form of onychomycosis [9]. He also included drawings of the clinical appearance of the disease (Figure 1.2). He described how he softened the nail by using sodium hydroxide, and it is important that to remember that at that time microscopes were still very simple and dyes were not used. Meissner also described and drew filamentous fungi and spores (Figure 1.3).

Figure 1.1 The first page from Meissner’s paper where he describes his discovery of the fungal nature of onychomycosis.

Figure 1.2 Meissner’s original clinical drawings of infected nails.

Figure 1.3 Meissner’s original drawings of the microscopic appearance of onychomycosis.

Most scholars give Meissner the honor of having discovered onychomycosis [12], although the fungal nature of onychomycosis had been suspected earlier. In a letter to the editor of The Boston Medical and Surgical Journal(today N Engl J Med) “On Fungus Ulcer of the Toe, or That Disease Usually Styled Inverted Toe Nail”, J.P. Leonard describes various methods for treating onychomycosis [13].

Onychomycosis and tinea pedis usually go hand in hand. It is hard to imagine that the first case of tinea pedis was described only 129 years ago by an Italian dermatologist, Celso Pellizzari [14]. Most of the early reports on onychomycosis and tinea pedis are from Europe [15]. The first reported case of tinea pedis in the United States was noted in Birmingham, Alabama, in the 1920s [16].

World War I troops returning from battle may have transported Trichophyton rubrum to the United States [16]. The first case of toenail onychomycosis presented in the United States is from 1937, when Montgomery presented a 28‐year‐old woman with onychomycosis before the Manhattan Dermatologic Society on 14 December 1937 [17]. However “mycotic conditions of the nails” were described much earlier in the United States and Guy and Jacob in 1923 recognized hyperhidrosis as a risk factor for onychomycosis and tinea pedis. They also understood that “injury is a definite factor; mycotic conditions of the nails, especially, often date from injury” [18]. In a personal case series from 1927, White reported on 1013 patients diagnosed with “fungus diseases of the skin” between 1910 and 1925 [19]. Only three patients were diagnosed in 1910 and 147 in 1925. Out of these 1013 patients, 23 (2.3%) had onychomycosis and 341 (33.7%) had tinea pedis [19].

The history of onychomycosis is short and parallels that of tinea pedis and the invasion of dermatophyte T. rubrum into the Western world [20]. T. rubrum is today the major cause of onychomycosis worldwide [21].

T. rubrum originated from West Africa and the Eastern world. The native populations of these areas did not develop tinea pedis or onychomycosis, probably because they mainly walked barefoot [22]. When the colonialists and soldiers arrived, wearing boots, which caused hyperhidrosis and maceration of the feet, it was easy for T. rubrum to find a new home. During the late eighteenth and early nineteenth centuries, there was increased urbanization and traveling. The great wars (World War I and II and the Vietnam War) may have contributed further to the spread of T. rubrum. Modern lifestyle with leisure travel and the “health boom” with frequent use of gyms and shared bathing facilities may have helped further with the dramatic increase of onychomycosis that we have seen during the past 100 years.

1.3 The Early Epidemiology of Onychomycosis

Onychomycosis is so common today that every dermatologist examines several cases a week or even several a day. On the other hand, during the nineteenth and early twentieth centuries onychomycosis was a very rare disease.

Julius Heller, a German dermatologist (1864–1931), published a book on nail diseases which he simply named Diseases of the Nails (Die Krankheiten der Nägel). It was first published in 1900 [23], and a second edition came out in 1927 [24]. This book can be considered the bible of nail diseases at that time.

In his book, Dr. Heller writes: “I myself pay close attention to the nail diseases and have, despite large nail medical material, at most seen 7–8 cases between 1896 and 1923” (one case every 4–5 years). What a contrast to the modern dermatologist, who can see several cases in a single day. Despite this, Heller’s clinical description is impeccable and also includes photographs (Figure 1.4).

Figure 1.4 Clinical photographs of patients with onychomycosis.

Source:[24]. Reproduced with permission of Springer.

The famous dermatologist Jean Darier collected material from 3000 cases of dermatomycoses. In this material there were only three patients with onychomycosis [25].

Dr. Sabouraud, considered by many to be the father of modern mycology, noted in 1910 in his classic monograph that out of 500 patients with superficial fungal infections only one (0.2%) had onychomycosis [11]. This is in great contrast to recent laboratory series, where more than 50% of the subjects have onychomycosis [26].

In the United States, Dr. Milton Foster looked at immigrants in 1915 on Ellis Island and found 101 cases out of 521 366 (0.02%) immigrants examined with onychomycosis (cited in Heller [24]). White, in 1902, examined 485 patients with nail disease and found eight with onychomycosis, or 1.6%, [27]. This is far from the figures seen today where at least 50% of patients with nail diseases have onychomycosis.

Onychomycosis was rare at the start of the 20th century but has increased dramatically during the last century. Krönke comments in his thesis that onychomycosis rose sharply in Germany after World War I [28]. This is understandable and likely, because of poor hygienic conditions during the war and close‐quarter living [29].

Data on the changes in prevalence of onychomycosis do not exist. However, by examining the ratio between onychomycosis and all other mycoses, one can predict the changes in prevalence of onychomycosis. Also, in hospital series that exist, there is information about all cases seen at these hospitals and how many of these had onychomycosis. In Figure 1.5 the ratio over time of onychomycosis compared to all other superficial mycoses is shown. In this figure it is...