This is very interesting.
We have previously written blog posts dealing with the connection between melanoma and Parkinson’s disease. And now, there is new research providing a new link between another skin condition and Parkinson’s disease.
What is Rosacea?
Rosacea is a chronic skin condition, classically characterized by a redness of the face. This is the result of dilation of blood vessels in the facial skin, and is usually accompanied by pustules and swelling. Rosacea is indiscriminate in which age group it afflicts and there are four subtypes: three specifically affecting the skin and another affecting the eyes (ocular rosacea).
An example of Rosacea.Source: Medscape
Rosacea is diagnosed in women almost three times more than men. It is also more common in people between the ages of 30 and 50, and appears to have a preference for Caucasians of northwestern European descent (hence it’s nickname: the “curse of the Celts”).
What has this skin condition got to do with Parkinson’s disease?
Well, back in 2001 this study was published:
Title: Skin function and skin disorders in Parkinson’s disease.
Authors: Fischer M, Gemende I, Marsch WC, Fischer PA.
Journal: J Neural Transm. 2001;108(2):205-13.
In this study, the researchers were investigating seborrheic dermatitis (similar to rosacea, this is an inflammation condition that presents itself as flaky, itchy, and red skin) and hyperhidrosis (abnormal increase in sweating) in Parkinson’s disease. They measured these afflictions in 70 people with Parkinson’s disease and 22 matched control subjects. Almost 20% of the people with Parkinson’s disease had seborrheic dermatitis and half of the Parkinson’s population had hyperhidrosis. The researchers also found that half of the Parkinson’s group also had abnormal sebum levels – sebum being a waxy substance produced by the skin (interestingly, we have previously mentioned sebum in a post about a lady who can smell Parkinson’s disease).
This was an interesting result, but it was never really followed up…until this last week, when another study was published:
Title: Exploring the Association Between Rosacea and Parkinson Disease: A Danish Nationwide Cohort Study.
Authors: Egeberg A, Hansen PR, Gislason GH, Thyssen JP.
Journal: JAMA Neurol. 2016 Mar 21. [Epub ahead of print]
The size of this new study is amazing: the researchers looked at data from an national database which includes all Danish citizens 18 years or older from January 1, 1997 to December 31, 2011. That is a reference population of 5.4 million individuals!
Of these, 22 387 individuals (43.8% women) received a diagnosis of Parkinson disease between 1997 -2011, and 68 053 individuals (67.2% women) had a history of the skin condition rosacea.
The general population rate of Parkinson disease was 3.5 cases per 10 000 person. But in the population that had a history of rosacea the rate of Parkinson’s disease was 7.6 cases per 10 000 people – almost twice as high as the general population. Interestingly, when they looked at the subtypes of rosacea, the researchers found that there was a more than 2-fold increase in the risk of Parkinson disease in patients who had a history of ocular rosacea.
Even more interesting: treatment with tetracycline – an antibiotic – appears to have reduced the risk of Parkinson’s disease. The researchers also noted that people with severe rosacea have the same risk of developing Parkinson’s disease as do those who have more moderate rosacea.
This is an interesting study, further indicating a connection between the skin and Parkinson’s disease. Whether the relationship indicates anything causal or simply occurring in parallel is yet to be determined. But given similar previous association, we obviously need to take a closer look at skin.