Parkinson’s disease (PD) can cause a whole host of non-motor symptoms, including symptoms related to the skin. This week we take a closer look at these problems.
Seborrheic dermatitis — patches of scaly, irritated skin
Seborrheic dermatitis is a common skin condition in the general population, but even more commonly found in people with PD. It causes patches of scaly, red skin and dandruff, primarily on the scalp and on the oily parts of the face such as the sides of the nose. In PD, it is thought to be caused by over-secretion of oils from the sebaceous glands in the skin. In much the same way that dysfunction of the autonomic nervous system (the nerves that control automatic body functions) cause non-motor symptoms in PD such as blood pressure dysregulation and urinary abnormalities, autonomic dysfunction of the nerves that control the oil glands of the face can cause seborrheic dermatitis.
A study demonstrated that seborrheic dermatitis in the general population was associated with a small increased risk of developing PD and may precede diagnosis, much in the same way that smell loss, REM behavior sleep disorder and constipation may precede PD diagnosis. Of course this does not mean that everyone with seborrheic dermatitis will go on to develop PD but it suggests that in some people, the nerve damage that leads to seborrheic dermatitis is a harbinger of PD.
Seborrheic dermatitis usually can be controlled with lifestyle changes or topical creams. Wash your skin regularly and avoid harsh soaps and products that contain alcohol. If the condition does not clear up, an over-the-counter mild corticosteroid cream may help. If simple changes are not effective, then consult with a dermatologist who may want you to try a prescription cream.
Sweating issues and abnormalities
Another common skin-related non-motor symptom of PD are sweating abnormalities, or sweating dysregulation. In its most pronounced form, people with PD describe episodes of sudden, profuse sweating that necessitate a change in clothing. But it could also mean reduced sweating for some people. These episodes can profoundly affect quality of life and can be understandably frustrating and embarrassing. 
Sweating dysregulation (like seborrheic dermatitis) is also caused by autonomic dysfunction, more specifically the inability for your body to regulate its temperature correctly. In people with PD, there can be pathologic changes in the parts of your brain that regulate temperature, as well as in the nerves that regulate the sweat glands. People with PD may experience increased or decreased sweating, or a combination of both. One common pattern is reduced sweating in the body with increased sweating in the face. Another temperature regulation symptom that some people with PD experience is the sensation of cold hands or feet.
Sweating dysfunction is being investigated as a biomarker of PD. A sudoscan is a medical device which can measure sweat gland function. It has been suggested as a potential diagnostic tool for Parkinson’s. More research needs to be done but it is encouraging whenever potential biomarkers are discovered because they may eventually help us diagnose PD earlier and more accurately.
Suggestions to alleviate excessive sweating
In some cases, episodes of profuse sweating take place as a medication dose is wearing off or during a period of dyskinesias. If the sweating episodes appear to be related to medication timing, then treatment may revolve around changing medication timing or dosages to reduce OFF time or dyskinesias. (This webinar addresses the issue of OFF time and dyskinesias.)
In other cases, the episodes occur at random, or occur primarily during sleep. Basic lifestyle recommendations to aid in the management of excessive sweating include:
- wearing light, airy clothing
- taking cool or lukewarm showers
- drinking ample water
- using moisture wicking and cooling sheets, pajamas, clothing and socks. These products are made of materials that absorb more water and dry faster than standard fabrics and can be helpful for some people with excessive sweating
- avoiding sweat triggers including spicy foods, caffeine and alcohol
If these simple suggestions are not effective, and often they are not, additional strategies are available. The following are treatments recommended for those suffering from excessive sweating in the general population, and have not been tested specifically in people with PD. In addition, these treatments are generally focal (applied to a particular area) and may not be as effective if sweating is widespread. Discuss these options with your physician:
- Prescription-strength anti-perspirant – Almost all anti-perspirants available over-the-counter use an aluminum-based compound as their active ingredient. If these are not effective, there are anti-perspirants with a higher aluminum content that are available by a prescription. Both over-the-counter and prescription strength anti-perspirants can be used in sweaty areas other than under the arms, such as the soles of the feet
- Topical glycopyrrolate – This is a gel (it also comes in the form of a medication-infused cloth) containing an anti-cholinergic medication that can be applied to areas that are typically sweaty. Anti-cholinergic medications can have side effects, including dry mouth, constipation and blurry vision, particularly as people age. However, a topical medication is thought to have fewer side effects than an oral pill whose impact is more widespread in the body
- Oral medications – Despite the fact that side effects may occur, oral anti-cholinergics (such as oral glycopyrrolate) to control sweating may be appropriate for certain people with PD
- Botulinum toxin injections of the underarms and palms are an effective treatment of excessive sweating in those areas
- A variety of procedures are available to reduce sweating. These include:
- Iontopheresis – used for excessive sweating primarily of the hands and feet. This is a medical device that applies a current across the skin which increases the permeability of the skin, or the ability of substances to pass through the skin. Treatments, conducted by placing the hands and feet in tap water and applying a current, have been shown to decrease sweating. If this is not effective, sometimes an anti-cholinergic medication is added to the water. Treatments must be repeated frequently (about once a week), but after an initial period, can be done at home
- MiraDry is a handheld device that delivers microwave energy to specific areas of the body thereby destroying the underlying sweat glands. Laser treatments can be used for this purpose as well
Skin cancer and Parkinson’s disease
Melanoma is a type of skin cancer consistently linked to PD. People who have had melanoma are at an increased risk for PD and people who have PD are at an increased risk of melanoma. Epidemiological studies have shown an increased risk of non-melanoma skin cancers in PD patients as well. Always be sure to talk to your doctor about any skin concerns.
Tips and Takeaways
- Non-motor symptoms such as sweating dysregulation and seborrheic dermatitis can be symptoms of PD
- Seborrheic dermatitis can usually be treated with lifestyle changes and over-the-counter creams. Sometimes prescription-strength creams are necessary
- Although many treatments have been developed for excessive sweating, they have not been tested specifically in people with PD. Discuss with your doctor to find out if any are a possibility for you.
- There is a link between PD and melanoma which you can read about in a prior blog.
- If any symptom is causing you discomfort or interfering with the quality of your daily life, be sure to discuss it with your doctor as it may be something that can be improved with treatment or modifications.