The illness of Charles Darwin: a retrospective diagnosis.

The topic of this blog is the much debated illness of Charles Darwin. Firstly, an effective clinical history of his illness will be attempted, describing and classifying the symptoms. Then, possible explanations for his collection of symptoms will be addressed; including previous attempts to explain his illness.

Before 1837, Charles Darwin had, considering the poor level of medical knowledge and sanitation during the period he lived in, quite good health. He suffered from scarlet fever when he was nine and developed a mouth infection at college prior to his travels aboard the Beagle, both fairly inconspicuous illnesses for the time. Furthermore, during his five year round the world trip, he was taken seriously ill on only one occasion, which he attributed to food poisoning. It is surprising, when the extreme conditions he would have endured aboard the Beagle are taken into account that he did not suffer from illness more often during the five year voyage. There are those who claim that Darwin suffered from symptoms prior to his voyage on the Beagle and that there is evidence for a genetic disorder. However there is a far greater consensus that Darwin only began to experience the symptoms of his disorder after his return.

This good health contrasts sharply with Darwin’s health after 1837. It was at this time in his life, (when he was aged just 28) when he started to suffer from the collection of symptoms that would plague him until he died in 1882 (aged: 73.) They began with fatigue, malaise, stomach cramps and headaches, but worsened throughout his life: including worsening neurological symptoms like tinnitus, dizziness, sensitivity to temperature, further headaches, muscle spasms and tremors; as well as worsening gastrointestinal symptoms such as vomiting and colic. Furthermore, he developed cardiovascular and respiratory symptoms such as palpitations and shortness of breath. He also went on to develop dermatological symptoms such as blisters and ulcers. All of this was also accompanied by bouts of anxiety and depression.

In terms of the character and pattern of these symptoms, whilst it is true to say that the symptoms were most severe towards the end of Darwin’s life, it is not true to say they followed a progressive pattern of disease. It appears that Darwin’s symptoms took on a remitting/ relapsing character; where he had periods of relative health followed by months of illness so severe that he was bedridden and unable to work. Furthermore, stress appeared to exacerbate his condition. Indeed it is said his period of worst health was 1847-1851. This was a period of great stress. Both his father and “favourite” daughter (Annie) died; Annie aged just 10 at this time. In addition, within this period, his closest friend and scientific confidant, Joseph Hooker, left on an expedition to the Himalayas for three and half years. This was devastating news for Darwin who was relying on Hooker for fine tuning his book. Another noted exacerbating factor was preservative chemicals, Darwin’s health would tend to deteriorate when performing experiments (with chemicals). The one apparent alleviating factor was Dr. James Gully’s water cure establishment in Malvern. Darwin was persuaded to attend by his wife Emma, and stayed for four months instead of the proposed three weeks. The treatment was mainly homeopathic and probably had no effect, but another component of the ‘cure’ was a ban on alcohol, rich foods (including dairy) and tobacco as well as compulsory walks. This would have likely improved Darwin’s health.
Some have tried to explain Darwin’s illness as stemming from psychological problems, the eminent psychologist John Bowlby suggested that it was somatisation (psychological problems and emotional trauma being expressed as physical symptoms) caused by a suppressed grief for the loss of his mother. However, the extent to which Darwin suffered from the symptoms and his relative detachment to his mother, suggests that this is no the case. Another psychological explanation for Darwin’s illness was that it was mainly caused by stress that accompanied the guilt and internal conflict he felt towards his own work towards: ‘On the Origin of Species,’ as he was fully aware of its religious implications as well as how many of his colleagues and friends would react. There is support for this in the timing of the onset of his symptoms around the same time as he began work on his book. However, the severity of the symptoms he experienced surely cannot be accounted for by such a theory.

One possible suggestion for Darwin’s illness, which is based on the effect of the Malvern water treatment, is that he was lactose intolerant, as the improvement seen would have been caused by the dairy free diet at the establishment at Malvern. Furthermore, in this disease patients have chronic gastrointestinal symptoms if lactose is not removed from the diet, which chronically can cause malabsorption in the gastro-intestinal tract potentially causing neurological symptoms due to ion imbalance within the blood. However, even if we make a significant assumption in that the cardio-respiratory symptoms are caused by a separate environmental heart disease, it cannot explain the more severe of his neurological symptoms, his dermatological symptoms or indeed his fatigue.

Another, potential explanation also focuses on gastrointestinal disease. Some have blamed Crohn’s disease; the main strength of this argument is that it fully explains the gastrointestinal symptoms as well as explaining the relapsing/ remitting pattern of his disease. Furthermore, stress is known to have a role in the onset of an acute episode in Crohn’s sufferers, as is the case with Darwin’s symptoms. In terms of the dermatological symptoms Crohn’s can typically cause apthous ulcers of the mouth and other skin disorders. However, this explanation also falls down in effectively explaining the cardio-respiratory symptoms as well as the neurological symptoms. Unless as with above they are attributed to stress or other incidental disease.

A further, much popular hypothesis (endorsed by Sir Peter Medawar), is that he contracted a parasite that caused chronic Chaga’s disease after being bitten by the Triatoma Infestans bug. This disease may have gastrointestinal manifestations as well causing heart problems and the neurological symptoms could be explained as being secondary to the other symptoms or indeed a response to chronic disease. However, the dermatological symptoms described are less easily attributed to Chaga’s, although they could potentially be linked to the immune response that is believed to cause most tissue damage in Chaga’s. There is further evidence against Chaga’s, in that usually, chronic exposure to the bug’s faeces is needed to cause an infection. A factor not present in Darwin’s case.

Perhaps the most important factor to draw from these attempts to diagnose Darwin is that the more popular explanations are all linked to the immune system, and produce their effects at least in part by an inappropriate immune response. This has lead some to believe that Darwin suffered from multiple allergies, Fabienne Smith the foremost among them. This is supported by the fact that much of Darwin’s family had some sort of allergy and the death of his daughter Annie appears to be a total immune collapse. In addition the stress and chemicals that exacerbated his symptoms are typical in an allergic condition.

In conclusion, whilst there are many compelling arguments for different causes of Darwin’s symptoms, and a significant volume of information on his symptoms, and eventually there may be a popular consensus as to his illness; it will never be possible to make a definitive diagnosis.

Bibliography:
http://www.darwin-legend.org/html/darwins-illness.htm
Campbell AK, Matthews SB. Darwin's illness revealed. Postgrad Med J. 2005 Apr;81(954):248-51.
The Rough Guide to Evolution by Mark Pallen
Darwin: A Life in Science by John Gribbin and Michael White
Kumar and Clark Clinical Medicine by Kumar and Clark