What causes itching in the middle of the back?
10% of people will develop an intense itch in the middle of their back over their lifetime! Many of my patients have an itchy back and it makes them crazy. Typically I can see the spot where there is a darkening of the skin indicating that they have reached back and scratched there for years. It's usually between the spine and one of their shoulder blades. The itchy area is well localized and usually about the diameter of a tennis ball. When anything touches the skin it starts the itching. This includes fabric, a tag in a garment, the clasp on a bra, or simply the scales of dry skin.
This itchy phenomenon is called notalgia paresthetica, and there hasn't been agreement on what causes it until now - making the Itch Seminar an exciting highlight from my 2011 American Academy of Dermatology meeting!
It's now agreed that notalgia paresthetica is caused by nerve impingement in a spinal nerve. As the nerve exits the spine, a small branch curves around to innervate the skin. It travels through a big muscle to reach the skin and on its journey it gets squeezed. The squeeze usually happens in or around the spine. It doesn't necessarily mean there is anything severely damaged in the spine. The impingement can come from something as simple as a spinal calcified spur, which we all get as we age. It's why this frustrating mid-back itch comes with age. When you have an itch that happens at a spinal level it's called neuropathic itch or, more precisely, neuropathic pruritus. The skin is normal and not the cause, it's simply "downstream" from the problem and you perceive it as the itchy spot. The "downstream" skin is hypersensitive though because its nerve is "tweaked." This means that minor sensations, like dry skin scales, can set it off. It can also be triggered by rough clothing, scratchy tags on garments, etc. The best treatment, in my opinion, is to keep the itchy back skin very well hydrated using an alpha hydroxy acid containing moisturizer such as Am Lactin Cream (which is available over the counter) or, better yet, my Anti-Aging Body Skin Care Kit with professional strength glycolic acid to condition and hydrate itchy and scaly skin.
These products not only hydrate the skin, treating dryness, but the alpha hydroxy acid also removes dead skin scale, which acts like tiny feathers to stimulate the mid-back itch. I also recommend that my patients wear soft fabrics on this part of their skin and remove those itchy clothing tags. When simply moisturizing and wearing soft fabrics doesn't work, the next step is to throw an ice pack on the itchy back skin. Ice sends a very loud temperature message up the poor little impinged nerve and this really does override the itch message. Think of it like the way loud music drowns out your conversation at a concert. Temperature and itch travel on the same nerve pathway, thank goodness, so we can use cool to override itch. Don't use heat; it will actually increase the itch because of its local effect on the skin. Scratching is much less effective than an ice pack at giving you relief for notalgia paresthetica. Plus, it will cause your skin nerves to thicken up over time and thick nerves can send even louder itch messages. When I see a darker tan color on the itchy area of my patient's skin it usually indicates that they've resorted to scratching and it tells me that the nerves are probably thickening up. I find that prescription cortisone creams can also give my patients some relief when they are going through a really itchy spell. Ask your doctor if you think this might help you. Lastly there are oral medicines that doctors use for neuropathic pruritus. Most of these medicines have complex side effects, so they are a last resort and any discussion of them needs to happen with your doctor. Don't forget things like acupuncture and biofeedback, which can be safer options that I've found can work for some people. If you found this post interesting, you may also want to read some of my other articles on common skin conditions: What's the Best Way to Remove Skin Tags? Intertrigo: The Red Rash of Skin Folds Cracked, Dry, Brittle, and Splitting Fingernails: Dermatologist's Tips