My first rosacea flare up happened when I turned 40 (14 million Americans over the age of 30 suffer from rosacea). I looked like Mrs Angry until I was given some 0.5% Desonide, a low potency cortisone cream. Since then I've worked out how to prevent seeing red (at least most of the time): click here for some of my rosacea management tips. None of it is rocket science, but now researchers seem to be getting closer to understanding the root cause of rosacea and treatments that don't involve steroids.

In 2007, Dr Richard Gallo of the University of California discovered that peptides known as cathelicidins and the proteolytic enzymes that activate cathelicidins in the skin are abnormal in patients with rosacea. Cathelicidins are antimicrobial peptides and the enzymes in the skin of rosacea sufferers cause them to produce these peptides in an abnormal form. This revelation turned out to be a breakthrough and sent a whole bunch of scientists off in a new direction. Gallo himself has now done follow up research and he thinks that rosacea patients' innate immune systems, overall, are abnormal.

A study in Belgium of all the research in the last couple of years has made a connection between the regulation of cathelicidins and vitamin D. This is because there is what they call "a previously unknown and unexpected link between innate immunity and the vitamin D system".

Interestingly, one in four Americans are vitamin D deficient and medical researchers believe that low levels of vitamin D are responsible for a whole range of ills, from muscular weakness to autism. The best way to get your daily dose of vitamin D is to spend 30 minutes a day exposed to sunlight. Failing that, there oral supplements available, specifically vitamin D3. A synthetic form of vitamin D is available in a cream called Calcipotriene. It may also help to control sebum production and, therefore, provide some relief for acne sufferers. Apparently, vitamin A interferes with D, so avoid retinols if you decide to give this therapy a go.