Treating pain as a disease and not just a symptom
http://www.pharmaphorum.com/2009/08/26/treating-pain-as-a-disease-and-not-just-a-symptom/

The treatment of chronic pain is recognised as one of the largest unmet needs in the medical community. Neuropathic pain, a form of chronic pain, is caused by lesions to the nervous system resulting from trauma/compression, infection, metabolic disease, toxic chemicals, or other insults that generate prolonged abnormal changes in the nervous system function (Costigan et al 2009). Common symptoms of neuropathic pain include spontaneous, burning pain and pain hypersensitivity. This manifests as either an exaggerated response to a mildly painful stimulus (hyperalgesia) or pain resulting from a normally non-painful input (allodynia). Current treatment options remain inadequate either due to low efficacy or significant side effect burden. Over the last 20 years, no new pain targets have been successfully exploited to treat this debilitating condition, despite massive investment from the pharmaceutical industry.
Now is the time to look at pain and its treatment in a different way. Pain is traditionally associated with medical conditions like diabetes, cancer and neurological dysfunction and treatments are largely aimed at symptom relief. As a result, less attention is made to the pathological processes that underlie pain, its initiation and development. Over recent years, it has emerged that damage to peripheral or central nerves results in changes that alter neuronal plasticity and nociceptor pathways, all ultimately responsible for pain and sensory amplification. Furthermore, multiple mechanisms are implicated in the manifestation of neuropathic pain, including genetic and environmental factors, so that identification of novel approaches to treating chronic pain requires careful evaluation of these multiple inputs. The role of glial cells in chronic pain has emerged over the last 10 years and has brought a new level of complexity to pain biology. The knowledge, however, that highly integrated neuro-immune interactions in the central nervous system play a key role in the cellular mechanisms responsible for the development of chronic pain has opened up additional opportunities for new medicines. Mapping a way through these complex processes is essential in the quest for new treatments. Translational research, linking pain in humans to preclinical pain models, is an essential component of drug discovery and should lead to the identification of new medicines to treat this underserved medical need.

As physicians, we are motivated to find the etiology (cause) of any condition. However, as pointed out by Dr Suske, the symptom can be be classified as a disease if no cause can befound. The classic example is fibromyagia. There are many symptoms, yet no measurable findings.
However, we can classify pain. We can use many modifiers to compare it. And the International Cassification Of Diseases has a code classification for it

338.2 Chronic pain
Excludes:
causalgia (355.9)
lower limb (355.71)
upper limb (354.4)
chronic pain syndrome (338.4)
myofascial pain syndrome (729.1)
neoplasm related chronic pain (338.3)
reflex sympathetic dystrophy (337.20-337.29)

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338.4 Chronic pain syndrome
Chronic pain associated with significant psychosocial dysfunction

Hi Frank. I found your question interesting also. Traditionally, pain has been viewed as an acute symptom of some other injury or disease. What we have been learning about chronic pain over the last couple of decades has broadened that considerably. If an individual suffers with pain for a period of time and in spite of visits to professionals, is not examined or treated beyond the injury or disease underlying the pain, it can give rise to a whole new disorder, i.e. chronic pain. With this knowledge in hand, it is important for physicians to be as aggressive in dealing with pain, as they are with other symptoms/disorders. What I believe we are seeing so much more of is patients who started with pain and after a period of time with inadequate treatment, the pain appears to change the brain's chemistry in ways that contribute to "chronic pain states."

With this knowledge in hand and research increasing, there is an opportunity to 1) adequately reduce the patient's pain in the beginning and 2) potentially thwart a situation which allows the brain chemistry to become so altered that this patient must rely on stronger medications to achieve a quality of life.

Somewhere in that time period, pain becomes a sydrome (or medical disease) in and of itself.

This is a timely question on so many levels. There are patients who fear asking for help in the early stages of pain. Some are fearful that they may be viewed as "drug-seeking" or maybe they heard the news about a famous person who lost their life to some form of pain medication. In addition, there appear to be physicians who discount the importance of the information they receive from their patients about the significance of the pain on the ability to work, to play an to plan. Other times, it comes down to a lack of clarity on what types of treatments work best for pain from different sources. Perhaps, this is augmented by less time to keep up with the research.

From a human standpoint, I would assert that pain is always a state of disequilibrium, or dysfunction in the body. Although it may provide an important clue to some other health issue, by the very fact that it causes a degree of suffering, it should be reduced (treated) to help the patient to channel his/her energy towards recovery, if that is a viable option.

Finally, there is the issue of cost. If patients were encouraged to communicate their pain as early as possible to a trusted physician, and that physician managed the pain aggressively and appropriately, there would be one instance of potentially reduced costs in future chronic pain treatment. Consider the numbers of patients who are diagnosed with chronic pain in this country (I am sorry that I cannot recall the number. It is very high). If these patients were aggressively treated for their pain, before the brain chemistry began malfunctioning, a lot of money could be used elsewhere in healthcare.

Thanks for the opportunity to add my perspective. I am not a physician. I did work in health care for twenty-five years. I now have a chronic pain problem of my own (neuralgia), which was discounted for four years before I was properly diagnosed. Individuals who experience life-altering conditions have a lot to offer the medical industry. That is why I am here.

My best to you,

Victoria Grove

I agree with many of the comments regarding chronic pain as a disease in itself - to me it seems entirely logical that if we can have dysfunction of the pancreas and end up with diabetes, or dysfunction of indeed any other tissue, organ or system, it makes just as much sense that dysfunction of the pain 'systems' can also occur.

On the other hand, I also think that pain can get the blame for long-standing problems when actually it's not the pain per se, but the attitudes and beliefs about the pain that create the problems (or disability). There are many people living well in the community despite having ongoing pain - and have no disability associated with it at all, while there are others with little or no reported pain intensity but significant disability that seek help for their pain - is it the pain, or the disability that needs attention?

While I'm certainly keen to see people attend to acute pain as quickly and comprehensively as possible, I'm cautious about this. It's not simply about abolishing the pain in order to minimise the likelihood of central sensitisation and/or other peripheral problems from contributing to ongoing pain. It's also about addressing other mechanisms, both micro and macro, that contribute to disability. This usually seems to mean addressing psychosocial factors such as how the individual makes sense of or interprets his or her experiences, and the other contingencies operating in the person's life.

My concern is that in the rush to 'find the cause' or 'abolish the pain', advocates of these biomedical approaches will find it difficult to incorporate these psychosocial and functional aspects that the literature has repeatedly found important.

So, to answer the question, is chronic pain a disease in itself? I'd say yes - but not a disease with a single 'cause'.