Is it 2.7% or over 10% of people in Ireland that are affected by Rosacea?
Articles based on new research (published in the July issue of the Journal of the American Academy of Dermatology) suggest that only 2.7 per cent of the population of Ireland are affected by rosacea, whereas internet and other sources frequently indicate that over 10% of the population affected. Why is this?
A recent study in Ireland identified the prevalence of ‘papulopustular rosacea’ was 2.7% of population; reports on the internet say the incidence of Rosacea in Ireland is perhaps four times larger. In simple terms there are four types of rosacea, and ‘papulopustular rosacea’ is only one of these.
In order that the recent study could be more scientifically accurate in relation to identifying the effect of UV on ‘the incidence’ of rosacea, it concentrated on papulopustular rosacea. However there are various types of rosacea, in technical language these are called rosacea subtypes and were defined by a committee and panel of worldwide medical experts:-
Subtype 1 (erythematotelangiectatic rosacea), characterised by flushing and persistent redness, and may also include visible blood vessels.
Subtype 2 (papulopustular rosacea), characterised by persistent redness with transient bumps and pimples.
Subtype 3 (phymatous rosacea), characterized by skin thickening, often resulting in an enlargement of the nose from excess tissue.
Subtype 4 (ocular rosacea), characterized by ocular manifestations such as dry eye, tearing and burning, swollen eyelids, recurrent styes and potential vision loss from corneal damage.
Therefore the total number of people suffering from all types of rosacea will be much higher than those suffering only from Subtype 2 (papulopustular rosacea).
Does UV exposure play a causative role in the skin disorder or not?
It is widely reported that UV exposure and exposure to the sun plays a causative role in Rosacea, and persons at risk are advised to keep out of the sun, wear a sun hat or wear sun block.
The recent study says “the 2.8% prevalence of papulopustular rosacea identified in ‘outdoor workers’ in Ireland subject to high UV exposure was not significantly different from the 2.6% rate among hospital workers, thereby dispelling the notion that UV exposure dermaroller figures prominently in the etiology of rosacea.”
Again this figure applies only to one subtype of rosacea (papulopustular rosacea) and the previous statement should be “thereby dispelling the notion that UV exposure figures prominently in the etiology of papulopustular rosacea”.
It is probable that subtype 1, (erythematotelangiectatic rosacea), characterised by flushing and persistent redness, (typically includes visible blood vessels) is more likely to be made worse by exposure to the sun and weather elements.
Various people who have subtype 1 (the rosy cheeks with visible blood vessels) would not have been included in this study. Therefore although UV exposure does NOT figure prominently in the etiology of papulopustular rosacea, it may figure more prominently in other rosacea subtypes.
The statement gender is not tied to rosacea risk may also be misleading. It is suggested that the following wording should be used; the disease prevalence also proved unrelated to gender or family history of papulopustular rosacea.
Women will typically be more concerned at a visible increase of tiny blood vessels near the surface of the skin (e.g. the cheeks) causing ‘those Irish Bosco Cheeks’. This type of rosacea is typically subtype 1 (erythematotelangiectatic rosacea) and was not included in the study and so the conclusions of the study do not apply to this type of rosacea.
Conclusion: The statement (or an article with the title) ‘UV exposure, gender not tied to rosacea risk’ could be misleading to the unscientific layman because it is based on research that used only one of the four rosacea subtypes. An alternative statement or article title could be ‘UV exposure, gender not tied to papulopustular rosacea risk’
The study was on the incidence of subtype 2 papulopustular rosacea; a person may have a very mild form of subtype 1, which would normally go unnoticed, however exposure to the sun, together with triggers would cause it to become a noticeable form of ‘rosacea’. Therefore whilst UV and sun exposure may not affect the incidence of subtype 2, they could affect the severity and noticeable incidence of other subtypes.