CRPS and Allergies: coincidence or causal?

It amazes me just how many people with CRPS subsequently develop an allergy or even multiple allergies. The most recent example I came across was a gentleman I was speaking to last week. It’s a little over two years since his CRPS diagnosis and for the first time in his life he’s found himself suffering with hay fever. In fact, the recent and well-publicised “pollen bomb” in the UK has, in his words, “absolutely floored me”.

But he seems to be only one among many and it doesn’t appear to be limited to just hay fever. Over the years, we’ve come across clients who have developed food allergies, pet/dust allergies and allergies to common medications – all after developing CRPS. Clients have also reported to us an apparent worsening of allergies they suffered prior to developing CRPS.

Of course, we mustn’t lose sight of the fact that all of us, whether or not we suffer with CRPS, can develop an allergy at any stage in our life. I know this from personal experience. Like the gentleman above, following an apparently allergy free childhood and adolescence, I developed hay fever as an adult in my 30s and for many years now, in the spring and summer, am never far from my antihistamines. However, the prevalence of ‘new’ allergies among CRPS sufferers does beg the question, is there a link?

Inappropriate response

Allergy UK very neatly describe an allergy as “the response of the body’s immune system to normally harmless substances, such as pollens, foods, and house dust mite. Whilst in most people these substances (allergens) pose no problem, in allergic individuals their immune system identifies them as a ‘threat’ and produces an inappropriate response.”

So, an allergy is the result of the immune system’s inappropriate, protective response to a perceived threat. Of course, it might be said that this is also a fairly neat, if somewhat simplistic, way of explaining the mechanism behind some of the symptoms of CRPS; research having demonstrated that inflammation related to CRPS is caused by the body’s immune response.

High levels of inflammatory chemicals known as cytokines have been found in the body tissues of people with CRPS. Cytokines, which are secreted by certain cells in the immune system, contribute to the redness, swelling and temperature changes which are, of course, among the typical symptoms of CRPS. It comes as no surprise then that researchers hoping to gain a better understanding of the mechanism behind the development of CRPS are studying, among other things, the activation of the immune system.

Common factor

So, the immune system is a common factor shared by allergies and many of the symptoms of CRPS. Interestingly, a study of CRPS Type I in orthopaedic patients suggested strongly that pre-existing allergies are a predisposing factor for the development of CRPS Type I in that particular group. But, from the other perspective, can CRPS cause allergies?

On the basis of the incomplete science alone, the answer seems to be ‘possibly’. However, if the anecdotal evidence is additionally factored in, I would say (boldly!) that the answer is ‘probably’. Ok, that’s not very scientific, but then I’m not a scientist! The point is though that like so many facets of this strange and devastating condition, the science is currently incomplete and that hard scientific evidence may always prove elusive. In the meantime, people living with CRPS need to be aware of everything the condition may throw at them, scientifically ‘proven’ or anecdotal.