Chronic itch is a frustrating experience. Sufferers of skin conditions like eczema know this all too well.
I know what you’re thinking. Why the hell is an osteopath writing about itch? Shouldn’t they stick to their scope of practice?
There are a few reasons:
- We treat people manually, usually to exposed skin, so we often come across people with skin conditions who aren’t managing them well, or are suffering from a persistent itch.
- Itching associated has a lot of parallels to pain. Both pain and itch are outputs of the brain and both can be caused by either peripheral causes (in the skin), central causes (in the nervous system), or a combination of both.
- Many of the general recommendations surrounding itch are within the scope of practice of an osteopath to recommend.
If you suffer from chronic itch, it is important to consult with your GP, and possibly a dermatologist, in order to get a diagnosis of your condition.
Your itch/skin condition could be the symptom of some underlying pathology that gets worse because you tried to self-treat.
We’ve all had an itch that needed scratching at some point in our lives.
Whether it was after being bitten by an insect or due to social contagion – like yawning, we tend to scratch ourselves when we see others doing it – or some other reason.
For some people though, itching is a daily occurrence, and the desire to scratch is often so strong that sufferers of chronic itch cause damage to their skin trying to find relief.
It used to be thought that itching was a sub-group of pain, but it’s now understood to be a separate entity, though they share many similar traits physiologically.
There are different mechanisms of itch, which we can classify as peripheral or central, just like pain.
This is an important concept to grasp, because most medical treatments are only directed at peripheral drivers of chronic itch.
There are 4 classifications of itch:
- Dermal or pruriceptive itch: refers to an itch that results from activation of itch receptors in the skin. This activation is often caused by histamine (which is also the main driver of hayfever).
- Neurogenic itch: is an itch that originates in the central nervous system, where itch-mediating pathways are activated. This can occur with the spinal application of opioid medications, or more commonly in skin conditions, inflammation within or affecting the central nervous system.
- Neuropathic itch: also originates in the central nervous system, but is caused by diseases of the nervous system.
- Psychogenic itch: is related to illusional states.
When it comes to itch associated with eczema and other similar skin conditions, we want to focus on dermal itch and neurogenic itch, as these are the mechanisms involved.
Why does it feel good to scratch?
Normally, when we are exposed to a scratching stimulus, we withdraw, as we perceive it as either painful or unpleasant.
However, when we are itchy, we welcome the scratching sensation as relieving.
When we scratch an itch, there are multiple brain areas that are active, including areas involved in both pleasure and pain.
Both active (scratching yourself) and passive (having someone else scratch you) forms of scratching have been shown to relieve itch.
Interestingly, scratching nearby to the site of the itch also relieves the itch, suggesting a central inhibitory effect, rather than a local effect from scratching.
Chronic Itch Is More Than Skin Deep
Dermal/pruriceptive itch is mostly mediated by sensory nerves that are embedded in the skin called C-fibres.
There are two kinds of dermal itch:
- Histamine mediated.
- Non-histamine mediated.
Histamine mediated itching
This typically occurs when we are bitten or scratched, and there is a release of local histamines as part of the immune response.
This also occurs with conditions like hayfever.
With chronic itch related to skin conditions, this is often managed with topical steriods and over the counter anti-histamine tablets (the same ones you would take for hayfever).
Non-histamine mediated itching
This occurs in people with certain diseases (cancer, HIV/AIDS, liver disease) and as a side effect of certain medications.
It is also a big feature of the itch associated with chronic skin conditions, like eczema, though it’s not commonly discussed.
This type of itching is a massive issue – it’s difficult to treat and causes lots of distress for the suffer.
One key feature of this form of itch seems to be neurogenic inflammation. Mentioned above, this is itch that originates in the nervous system.
Setting off positive feedback loops, this inflammation is self perpetuating, as long as the stimulus is in place.
Topical treatments don’t work well for this, which is why many eczema sufferers get short term relief from creams, but in the long term may continue to suffer.
In order to get lasting relief, the root cause of the neurogenic inflammation must be addressed.
This could be down to a number of factors (or combination of), including:
– Gastrointestinal distress
– Psychological stress
– Environment exposures
Considering the systemic nature of most chronic skin conditions, and their relationship to other conditions (such as asthma and hayfever in eczema sufferers), it makes sense that there is an underlying physiological dysfunction that is common to all.
One such proposal is the relationship between cellular energy and inflammation. Cellular energy is needed on a constant basis for our cells to function and reproduce optimally.
It is increasingly apparent that bioenergetic function and inflammation are interdependent processes. (2)
This simply means, when cellular energy is low, due to lifestyle factors or illness, inflammation results.
Without addressing lifestyle factors that could be contributing to chronic inflammation, most sufferers of chronic itch related to skin conditions will not get complete respite from their itch.
How To Treat Itch
The best approach to resolving a chronic itch associated with a condition like eczema would be multi-modal and address all the causative factors.
- Topicals as directed by a dermatologist, to provide symptomatic relief and manage flare ups.
- Anti-histamines to address the histamine component of the itch (usually in eczema the two kinds exist in tandem).
- Dietary modification: detection and elimination of dietary irritants, which can be determined by performing an elimination diet with the assistance of a dietitian other qualified health practitioner.
- Supplements as directed by a health practitioner based on testing, to address any nutritional deficiencies (commonly Vit D and magnesium when it comes to neurogenic inflammation).
- Meditation/mindfulness or relaxation to alleviate and manage psychological stress. Alternatively, go for a walk in nature, which has proven stress relieving effects.
Like most chronic conditions, there is no single cure-all for chronic itch, thus a multi-modal approach works best.
Whilst most medical approaches can work well for symptomatic relief, there is yet to be any treatment approach that delivers a change to the underlying pathology.
With this in mind, long term strategies to deal with neurogenic itch related to skin conditions should address factors related to both chronic lifestyle related inflammation as well as local skin irritation.
This blog post was written by Dr Nick Efthimiou (Osteopath), founder of Integrative Osteopathy.
This blog post is meant as an educational tool only. It is not a replacement for medical advice from a qualified and registered health professional.
(1) McMahon, S.B., et al, Wall and Melzack’s Textbook of Pain, Elsevier Saunders, Philadelphia, 2006