Itchy Back or Arms

Itchy back or arms are a common skin complaint in my dermatology practice. The classic and most common cause of an itchy back is a term called notalgia paresthetica. This can also happen on the arm where it is called brachioradial pruritus. It can happen on the scalp where it is called cervical dysesthesia and it can happen in the groin where it is called gentile pruritus. The causes are all similar - they are neuropathic itch syndromes! 

What is notalgia paresthetica?

• Itching in one side of the back, often between the spine and the shoulder blade.
• The itchy skin is well localized and usually the size of a tennis ball.
• 10% of people will develop notalgia paresthetica at some point in their life.

What causes notalgia paresthetica itching on the back?

• It is caused by spinal degenerative disease and resultant nerve root impingement of a sensory nerve the innervates the itching area of the skin.
• It usually begins in adulthood, as do the spinal degenerative changes.
• The nerve impingement is small and not associated with pain or other symptoms. It is often due to spasm of a muscle near the location of the spinal degenerative disease.
• There is nothing wrong with the skin, the itch is neuropathic, meaning of nerve origin.
• The skin is hyperesthetic meaning highly sensitive. Anything touching the skin will start the itch, including fabric. Flakey dry skin is especially itchy. 
• Over time, scratching will lead to scars and hyperpigmentation of the skin where the itch sensation is perceived. 
• The itch is vexing because it really can’t be satiated with scratching. Scratching is temporarily distracting but does not relieve the itch.

What is brachioradial pruritus?

• Itching in a specific area of one or both arms, often the forearm near the elbow, though any area on the arm, upper back, and neck can be affected. 
• It is caused by nerve root impingement of the cervical spine.
• It usually begins in adulthood, as do the spinal degenerative changes. 
• Like notalgia paresthetica, the itch is neuropathic, meaning it is of nerve origin and it is not caused by anything on the skin.
• Itch is a burning, prickling or stinging itch.
• Skin is hyperesthetic meaning hypersensitive; tactile stimulation will start the cascade of intense itch. Even light touch or flakey dry skin can lead to itch.
• Over time scratching leads to scarring and hyperpigmentation of the skin
• Sun damage of the skin plays a role, though we don’t know how. Also, sun will start the itching. The driver side arm is usually itchier. 

I’ve described these itch syndromes to my patients as a “ghost itch” for years. The itching is vexing because scratching the skin does not stop the cause of the itch. It does, however lead to scarring, skin hyperpigmentation and more itching!

What is the best treatment for notalgia paresthetica and brachioradial pruritus?

This is what I do with my own notalgia paresthetica, and what I instruct the patients in my dermatology practice to do to help control theirs:

• Always keep the skin well moisturized and free from flakes and dryness. This is really important. Dry skin flakes act like feathers to tickle you into itching!
• 
  AHA moisturizers and cleansers with exfoliation work best for my dermatology patients. AHA’s, such as glycolic acid, help prevent flakey skin scale. They also change the structure of the dead skin cell layer, effectively polishing it so that is less likely to be stimulated by tactile sensation. I have my patients use my Ultra-Fast Body Smoothing Triple Action Kit. It’s what I use myself.  You will need a Back Applicator to apply the lotion generously to your back. 
  
• 
  When not using the AHA cleanser and moisturize, be sure to only use gentle cleansers, such as my Naturally Best Bar Soap with your exfoliating shower cloth, sponge or mitt. Always apply a rich moisturizer after every bath or shower. Ideal options are my Natural Lotion.
  
• Sun protection of the itchy skin is important. Sun damage plays some role in the problem. It can also start the cascade that leads to itch. Use sun protective UPF 50 clothing or broad spectrum SPF 30+ sunscreen on exposed skin daily. 
• Avoid heat because heat makes the itching worse.
• Use cool water compresses or an ice pack to soothe itch.
• Wear soft fabrics on the hyperesthetic skin of these neuropathic itch syndromes. 
• Avoid scratching! Yep, this is important. Scratching leads to a thickening of the nerves and you don’t need any more nerve signaling of sensation and itch. 

What are other causes of an itchy back?

Another common cause of itchy back is overgrowth of Pityrosporum yeast and the rashes that result including

• Tinea versicolor, 
• Back seborrhea (dandruff), 
• Pityrosporum folliculitis.

For this reason, the ingredient zinc pyrithione products, such as my Foaming Zinc Cleanser will help if this yeast is the cause of your back itch. I have included pyrithione zinc cleansers and acne kits in the products listed below.

Are there other treatments for notalgia paresthetica and brachioradial pruritus beyond skin care?

Yes, there are medical, surgical and complementary treatments for these neuropathic itch syndromes. Options include oral medications, injections, prescription topical medicines, surgery, nerve stimulation and more. There is also massage, acupuncture and complementary medical treatments. If your neuropathic itch does not respond to skin care as I have described here then talk to your doctor about an evaluation and treatment plan. In my practice, I always start with skin care because of the risk to benefit ratio and the fact that it is a good foundation upon which to build other treatments until we get relief.