Patients with rosacea might have increased risk of dementia—in particular Alzheimer’s disease, researchers cautioned in the Annals of Neurology online ahead of print (Apr. 28, 2016). This connection follows a report from the same group linking rosacea and Parkinson’s disease [Derm.city (Apr. 5, 2016)].
This study comprised a total of 5,591,718 Danish citizens aged ≥ 18 between Jan. 1, 1997 to Dec. 31, 2012, including 82,439 patients with rosacea.
Rosacea is characterized by elevated expression of certain proteins—including matrix metalloproteinases and antimicrobial peptides—that are also involved in various neurodegenerative disorders such as Alzheimer’s disease and other forms of dementia. Because of this potential link, a team from the University of Copenhagen in Denmark investigated the association between rosacea and dementia in Danish registers.
Findings revealed that a total of 99,040 individuals developed dementia, of which 29,193 were diagnosed with Alzheimer’s disease. According to the investigations, after adjustments for potential confounding factors, patients with rosacea had a 7% increased risk of dementia and a 25% increased risk of Alzheimer’s disease compared with individuals without rosacea.
Additional, data showed that women had a 28% increased risk of Alzheimer’s disease and men had a 16% increased risk if they had rosacea. When results were stratified by age at study entry, the risk of Alzheimer’s disease was only significantly increased in individuals ≥ 60 years (who had a 20% increased risk).
Interestingly, the authors reported that when analyses were limited to patients with a diagnosis by a hospital dermatologist of rosacea only, the increased risks of dementia and Alzheimer’s disease were 42% and 92%, respectively.
“A subtype of patients have prominent neurological symptoms such as burning and stinging pain in the skin, migraines, and neuropsychiatric symptoms, suggesting a link between rosacea and neurological diseases,” explained lead investigator, Dr. Alexander Egeberg, of the department of dermato-allergology at Herlev and Gentofte Hospital, in Copenhagen, Denmark.
“Indeed, emerging evidence suggests that rosacea may be linked with neurological disorders including Parkinson’s disease and now also Alzheimer’s disease. There are certain mechanistic overlaps between rosacea and Alzheimer’s disease that may explain the observed association, albeit the pathogenic links between these conditions are still unclear,” added Dr. Egeberg, who was quoted in a press release.
Dr. Egeberg noted that it is important for patients to remember that having rosacea does not necessarily mean that they will develop dementia; however, the results may provide new insights into the link between the skin and neurodegenerative disorders. Further research is warranted to examine whether treating rosacea may also modify patients’ risk of developing dementia.