8. Dupuytren diathesis

8.1 Introduction

Of the utmost importance in counselling patients with Dupuytren's disease is the expected outcome of treatment. Beside the quality of the surgery, certain characteristics of the patients certainly play a role.

Hueston (1985c, 1990a) has observed that certain features of Dupuytren's disease dictate a more aggressive course of the disease as well as a greater tendency for recurrence after operation. He thinks that the patients showing those features have a greater expression of the disease or diathesis. Quoting the Oxford English Dictionary, he defines the diathesis as "a permanent condition of the body which renders it liable to a special disease". He ascribes, rather empirically, the appearance of new Dupuytren's tissue either in an operatively cleared zone (recurrence) or beyond the area of operation (extension) to the strength of the diathesis. It is therefore manifestly important to assess as well as possible the factors indicating that strength.

Beside a racial factor, he recognises four signs of a strong diathesis: an early onset of the disease, bilaterality, a positive family history and the involvement of other areas.

8.2 Race

Except the extremely rare reports of Dupuytren's contracture in isolated African (eight cases) (Furnas, 1979; Plasse, 1979; Zaworski et al., 1979; Mennen, 1986), Indian (ten cases) (Srivastava et al., 1989) and Vietnamese (one case) (Maes 1979), the disease had not been seen in non-Europeans until the recent reports in Japanese by Egawa et al. (1985, 1990). Even within Europe there seems to be wide variations not only in the incidence but also in the strength of the manifestations.

The incidence in northern Europe is higher than in the Mediterranean basin. In Italy there is a far higher incidence in the north than below Naples. This is consistent with the introduction of a genetic predisposition in the north-west from French and in the north-east from Austro-Hungarian invasions (Hueston, 1990a). Hueston (who worked in Melbourne) reports that despite the fact that Australia has the greatest Greek population outside Greece, he has seen only one Greek male with very mild Dupuytren's disease who on questioning revealed that his mother was Irish!

An explanation of this north-west European dominance of Dupuytren's disease has been that it was in the genetic spectrum of the Celts. More likely, in view of their wide raiding patterns, it could be regarded as a Viking disease (Hueston, 1985c; Whaley et al.,1993).

8.2.1 A Nordic Origin?

Medical historians have not identified any condition of the hand resembling Dupuytren's disease in exhaustive examinations of the medical writings of the Greeks and Romans (Whaley et al.; 1993). Therefore, by a process of elimination, the current prevalence of the disease in Europe dictates that the other great colonial power in recent history, i.e. the Norsemen, were responsible for its spreading. The Norse incursions on Europe in the Viking Age would have been a suitable vector for the disease.

The Nordic origin of the disease was first suggested by Early (1962) who made a comparison of its incidence in various countries and found that it was highest in Denmark. He also suggested that "if one postulates the condition as having arisen in one particular racial group then the variable distribution in other parts of the world might be explained on the basis of migration from that group". The identification (Whaley et al., 1993) of four miracle cures in the Icelandic sagas, which constitute a large part of the written tradition of mediaeval Scandinavia, in which the condition of the hand which was healed bears a resemblance to Dupuytren's disease suggest that the Norsemen may have suffered from the contracture. A study by Brouet (1986) in Toulon has noted a striking difference in the incidence of Dupuytren's disease in the dark-eyed Mediterraneans and that in the blue-eyed population of Nordic origin. A far stronger diathesis was observed in the Toulonese of Nordic than of local Mediterranean origin. Beside the observations of Brouet, the Nordic theory of origin is further supported by the apparently high incidence of the condition in those parts of Great Britain which faced the Norsemen, namely north-east England and the north and west of Scotland both of which were invaded and subsequently colonised, the former permanently and the latter for nearly 500 years (Elliot, 1988a).

The high incidence of the disease in Canada and the United States can easily be explained by the migration from the British Isles. The same Scottish and Irish predominance in the early white settlers in Australia and New Zealand explains the incidence in these countries as well.

8.2.2 Other isolated genetic events?

James (1985) reviewing the genetic pattern of Dupuytren's disease stated "It would seem probable that Dupuytren's does not occur among the Negroes, Chinese or Asiatic Indians of pure stock, or if later cases become known, they will be exceptional since they are unknown at present to surgeons working amongst these races". Since then cases have been reported in South African Negroes (Mennen, 1986), in Indians (Srivastava, 1989) and Chinese (Yih Liu, 1991). Yih Liu who observed 41 cases between 1970 and 1988 reports an increased prevalence since 1982 that he attributes to two factors. First, Dupuytren's contracture being more common in the older age groups, as the life span of people in Taiwan is increasing, the rate of prevalence would grow likewise. Second, it is possible that the patients took more care of this non-life-threatening disorder as a result of a steady increase in personal income in later years. This points out two possible bias in epidemiological studies of Dupuytren's disease in Third World countries.

In Japan, the demography of the condition has not yet been precisely established but from Egawa's results it seems that the disease is as prevalent in Japanese people as in Australian, British or Norwegian populations (Egawa, 1990). Egawa noted, however, that either the progression of the disease is slower in Japanese than in European people, or that the disease has a later onset in the Japanese population. Few Japanese patients progress to surgery for correction of the deformity.

The presence of the disease in races other than those of obvious North European descent probably represents isolated genetic events and has no bearing on the argument as to whether most cases today arise within the gene pool disseminated by the Norsemen. Indeed, the disease in Europe must have arisen earlier in history by the process of mutation.

8.3 Involvement of other areas and bilateral disease

In knuckle pads, plantar fibromatosis and penile fibromatosis the histo-pathological changes are identical to those observed in Dupuytren's disease. Hueston (1990a) interprets the presence of these ectopic deposits of fibroplastic tissue as an index of the strength of the diathesis because patients with knuckle pads are younger and develop more recurrences than those without. He does not publish statistics to support his assertion but McFarlane (1990b; McFarlane et al., 1990b) has been able to show that patients with ectopic sites of the disease have more recurrences and extensions after surgery.

For Hueston, a bilateral disease would also suggest a stronger diathesis but McFarlane found that this factor, acting alone, had no effect on the course of the disease.

8.4 Early onset of the disease

Determining the age of onset of a slowly progressing disease like Dupuytren's contracture is certainly a difficult undertaking because the recollection of elapsed time is at best imprecise. Hueston nevertheless states that an early onset of the disease is a sign of a stronger diathesis and McFarlane et al. (1990b) found that patients whose disease has started before the age of 45 develop more recurrences.

8.5 Family history

While a positive family history supports the assessment of a stronger diathesis, its absence should not lead into presuming a low penetration of the disease. In fact, Hueston states that a negative family history is the most unreliable of the factors outlined above in the evaluation of the strength of the diathesis.

As pointed out by McGrouther (1990c), this is hardly surprising in a non-lethal condition which often has an onset in later life and when many, perhaps most, of those affected do not seek treatment. Moreover the patients are often unaware of early signs of the disease and it would be surprising if relatives were more sensitive.

The most detailed analysis of the familial nature of Dupuytren's disease is that of Ling (1963) who examined 832 relatives of 50 patients in Edinburgh. He noted that the number of affected relatives rose from 16 % on history taking to 68 % after examination of relatives thus demonstrating the little statistical value that can be placed on the familial incidence as suggested by history alone. Ling's conclusion, corroborated by James (1985) who reports a study made by Thieme, was that a single gene, behaving as autosomal dominant, was likely to be involved.

Ling and Thieme, however, made their studies in Edinburgh were the incidence of Dupuytren's disease is high. None of the cases reported by Egawa (1990) in Japan, Mennen (1986) in South African negroes, Srivastava (1989) in Asiatic Indians or Yih Liu (1991) in Chinese of Taiwan had relatives affected by the disease.

8.6 Conclusion

Many studies have noted Dupuytren's disease in several members of a family, but the exact nature of the relationship remains unclear. As emphasised by McGrouther (1988), heredity was shown to be of great significance in Edinburgh where the disease is common but not in other countries where it is probably much less frequent. A population study with repeated assessment of family members over many years is certainly needed to clarify that question of heredity.

The idea of a Dupuytren diathesis, the term expressing a predisposition, is hard to define and has done little to clarify the situation. An index of the severity of the disease partially based on such proven unreliable factors as the existence of a positive family history or an early onset of the disease, cannot be very useful to establish the most appropriate treatment. We clearly need more objective data because as stated by McGrouther (1988) "all of these rather empirical views highlight the muddled thinking which prevails on pathogenesis and treatment".