Do you suffer from intensely itchy arms? In my dermatology practice, I see many patients who suffer from intense, and seemingly inexplicable, itchy arms and localized areas of their skin such as their mid-back. Until now, we doctors haven’t been able to explain why this happens. But, at last there's a conclusive answer. Like notalgia paresthetica, the problem with inexplicably itchy arm skin is apparently caused by a nerve impingement in the spine!
For me, this answer is one of my highlights from the American Academy Of Dermatology’s Annual meeting in New Orleans; when science figures out the cause of some mystery condition that I treat every day, I'm thrilled.
The Diagnosis for itchy arms is called Brachioradial Pruritus
It’s another one of those strange conditions where a precise part of the skin itches intensely, but it looks entirely normal. Patients with brachioradial pruritus can actually draw on their skin exactly where the itchy area stops and starts. I’ve been able to give my patients the name of the condition, but it’s been frustrating for all of us because I haven’t been able to give them a good explanation for the problem. Now, I can.
Of course, there are many other reasons why arm skin can itch, but usually there’s a rash on the arm and possibly on other parts of the body, too. Common examples include: dry skin, a contact allergic reaction like poison oak or wool allergy, psoriasis, etc.
When you have brachioradial pruritus, the intensely itchy skin looks completely normal before you start scratching. My right arm has the itch of brachioradial pruritus so I get to "observe" the condition daily. (There are other conditions where it's possible to have total body itching with no visible rash on the skin. But, in brachioradial pruritus, the itching is mainly limited to the arms.)
How do you know if you may have Brachioradial Pruritus?
Brachioradial pruritus usually begins in adulthood, especially if the skin on your arms is sun damaged.
In fact, sun exposure may also trigger the onset of itching. The skin looks normal unless you’ve been scratching. Unlike notalgia paresthetica, the central back itch, your arms are right there for you to scratch, and the itch is almost irresistible.
Years of scratching will cause a callusing and roughness of the skin, ultimately leading to white, red, and brown scars. These are "secondary skin changes" because they’re due to scratching. There are no primary changes (changes due to a rash) because the underlying skin is actually normal.
Both arms are usually affected, but often, the driver’s side arm is worse. The most common area of your arms to be involved is the forearm near the elbow, but any area on the arms, upper back and neck can be affected.
Itching is usually described by patients as a burning, prickling, or stinging sensation. Like notalgia paresthetica, the involved skin is hypersensitive to touch. Even light touch can set off the itching process. Sunlight can start it up too.
What is the new information about nerve impingement as an explanation for itchy arms?
We've suspected nerve impingement to be the cause of both brachioradial pruritus and notalgia paresthetica, but now it's conclusive!
Since the arms are involved, the impinged nerves are coming out of the cervical spine, so it’s cervical spinal abnormalities that cause the nerve impingement. Also, like notalgia paresthetica, the spinal abnormalities don’t need to be severe; they can be just a slight bulge of a disk, calcium spurs coming of the vertebrae, or other spinal changes that accompany aging.
There also seems to be a role for sun damage in brachioradial pruritus. It may be that both the nerve impingement and the degenerative changes in the skin that occur from sun damage are both necessary to cause the problem.
How do you stop the arm itching of brachioradial pruritus?
Treatment is tricky because the skin is actually normal and the message of "itch" emanates from the nerve near the spine, but there are things we can do to lessen the itch.
Why is sun protection of your arm skin so important with brachioradial pruritus?
We know that the sun plays a role in the problem, so, of course, sun protection is important. The best protection comes from wearing sun protective shirts that cover your arms. If that's not possible, then the mineral zinc oxide sunscreens are best. This is because, unlike chemical sunscreens, heat is not created when the UV rays hit the active sunscreen ingredients. Heat can make the itch worse.
One of my favorite zinc oxide sunscreen for the arms is Solbar Zinc Sunscreen. I've used this sunscreen in my practice for more years than I can count. In 2012 a customer said this about how it helped her brachioradial pruritus:
"Thank you, thank you, thank you."
"My arms began itching about three years ago during the summer. The condition seemed to worsen during the following years. My dermatologist prescribed topical lotions and an antihistamine which helped, but I continued to need ice daily to ease the unbearable itching.
A friend recommended your website as a resource. I began using AmLactin after each shower and Solbar before going outdoors. I’ve only used ice once or twice during the last three months.
I continue to use my prescription for Pramosone 2.5% lotion occasionally when I feel an itch coming on, but I’m now practically itch free." Linda M. A August 2012
It is actually not the Solbar Zinc that is important, it is the broad spectrum zinc oxide sun protection of your itch-prone arm! My current favorite zinc oxide sunscreens are my Sheer Strength Pure Physical Sunscreens because they use the latest invisible zinc oxide technology and contain no chemical sunscreen UV filters. The Sheer Strength Sprays are what I use on my arms when not wearing UPF 50 clothing in the sun.
Why is it important to keep your arm skin well moisturized and free of flaky, dry scale when you have brachioradial pruritus?
Tickling dry skin scale sets off the itch so moisturizing is really important. (Think of dry skin scale like tiny feathers brushing over your skin and tickling you.) I described my moisturizing recommendations in my post on notalgia paresthetica.
If your skin is really dry and irritated, you will need to start with bland, rich moisturizers. My top choice is my Natural Body Butter Cream with healing avocado, sunflower, apricot and jojoba oils, aloe vera, glycerin, shea and cocoa butters. It's magically soothing - trust me and my brachioradial pruritus and notalgia parestietica! Apply it daily after bathing. Eventually, glycolic acid products will work the best to control flaky scale. My favorite way to keep itchy arm skin well-moisturized and free from tickling dry scale is my Ultra-Fast Triple Action Body Skin Smoothing Kit.
The products are used to keep your skin from becoming scaly so that the scale won't tickle your skin into the cascade of unending itch. They are highly effective at doing the job!
What can you do when your arms start to itch?
- I tell my patients to slap an ice pack on the itchy skin because when the nerve is so busy telling you your skin is cold it can’t tell you that your skin itches.
- I also stress the importance of not scratching! Scratching causes skin nerves to thicken up and send even louder itch-messages to your brain in the future.
- Anti-itch creams with pramoxine or menthol sometimes help and can be used on an as-needed basis numerous times during the day. If you keep them in the fridge, they are cool, too, providing additional benefit for your itch.
Scratching also eventually causes scarring and uneven pigmentation. This can be disfiguring so we need to find some other solution for the itch. If sun avoidance, moisturizing, anti-itch creams, and the occasional ice pack don’t control the itch, then I prescribe a topical cortisone cream to apply while a patient is going through an itchy spell.
If none of this provides sufficient relief from itchy arms and skin, then just like notalgia paresthetica, there are strong oral medicines that can help block nerve signals. They have a lot of side effects, and I only prescribe them for my patients as a last resort. (If you think you have this diagnosis and need prescription treatment, you must discuss your situation with your personal doctor.)