NEW YORK (Reuters Health) - Danish researchers have linked the common facial skin disorder rosacea to the most frequent type of primary brain tumor in adults.
"Rosacea may be associated with an increased risk of glioma. However, it is important to note that the absolute risk is still low," Dr. Alexander Egeberg, of the University of Copenhagen, told Reuters Health by email. "Whether this is a causal link is not known, but there appears to be an overlap in the pathogenesis of rosacea and glioma."
"However, if patients develop neurological symptoms - such as headaches, memory loss, seizures, loss of muscle control, visual symptoms, dysarthria, cognitive decline, and personality changes - referral to relevant specialists may be appropriate," he said.
Dr. Egeberg and colleagues hypothesized that the shared pathogenic mechanisms dependent on increased matrix metalloproteinase (MMP) activity "could provide a link between rosacea and glioma," they explain in an article online January 27 in JAMA Dermatology.
They analyzed data in Danish population registries to identify nearly 5.5 million individuals who did not have rosacea or glioma on January 1, 1997, and followed up until the end of 2011. Maximum individual follow-up time was 15 years. More than 21,000 developed glioma and some 68,000 developed rosacea.
The researchers defined as reference population those who received a diagnosis of glioma after baseline but who had not been diagnosed with rosacea. They then calculated glioma incidence rates for the reference population and the rosacea population.
The incidence of glioma was 3.34 per 10,000 person-years in the reference population and 4.99 per 10,000 person-years among individuals with rosacea, with men having a higher glioma incidence rate in the rosacea population.
In analyses adjusted for age, sex, and socioeconomic status, the incidence rate ratios of glioma for individuals with rosacea was 1.36 overall (p<0 .001="" 1.27="" 1.47="" and="" for="" men="" p="" women="">
"Notably, the rosacea-associated increased risk for glioma was greater in men than in women, whereas gliomas and rosacea were generally more common among women," the researchers wrote. The overall cohort was split about evenly between women and men.
The researchers acknowledge that the results may not be generalizable to other populations because the Danish population is primarily white.
They concluded, "Rosacea is associated with a significantly increased risk for glioma. This association may be mediated, in part, by mechanisms dependent on MMPs."
"A subgroup of patients with rosacea have so-called neurogenic rosacea, with prominent neurological symptoms such as burning and stinging pain from the skin, migraine, and neuropsychiatric symptoms," Dr. Egeberg told Reuters Health. "This could suggest a link between rosacea and neurological diseases, and research in this area is warranted."
The LEO Foundation, the Novo Nordisk Foundation, and the Lundbeck Foundation supported this research. Dr. Egeberg is a former employee of Pfizer and one of his co-authors reported financial ties to Galderma.
JAMA Dermatol 2016.0>