oh yeah, I also found that wearing a bit of powder makeup over the area (I used bare minerals and/or clinique powder foundation) for special occasions doesn't bother mine, just gently wash it off as soon as you can b/c it gets extra flaky after a while (gross), so it might be ok for others to wear powder over it too!
I am 23, and have the same symptoms (redness, bumps, flaky/dry, tender, etc.) around my nose since Dec 09 (I also had it about 4 years ago, and again 2 years previous to that) and just went to the derm today and she diagnosed me with perioral dermatitis and gave my a script for doxycycline and a steroid cream called Cutivate which is actually some type of fluoride steroid, so I am definitely NOT going to be using that... I was using hydrocortizone until mid-April then stopped from suggestions found online that steroid creams only make the dermatitis come back much worse. I found that using Eucerin Calming Cream works pretty well to help with the dryness and redness but doesn't eliminate it, and also Aveeno calming foam soap works nicely, and even though it hurts, I rub the area gently with a wet washcloth to get the flakiness off every couple of days, wash and apply the eucerin, and the next morning it looks a lot better for that day. I also found washing it with dial antibac soap kind of helps but it's really drying. Also apple cider vinegar, the raw/unfiltered kind, works pretty nice at smoothing the skin after using it 2X daily for about a week I saw results, but beware that it stings! and you probably shouldn't use it if the area is really raw and/or bleeding (at least I wouldn't). I'll let you know how the doxy goes. I am on it for one month.
I also have these systems and they started when I used Toms of Maine peppermint bright whitening tooth paste.
I went to the dermatologist and they prescribed Minocycline an oral antibiotic. Hopefully it works!
I was pissed at Toms of Maine and recently discovered that they were bought out by Colgate-Palmolive :http://www.organicconsumers.org/articles/article_17306.cfm. So they are not so "natural" after all. I have also read that topical fluoride was "pro-inflammatory" and may be a cause in this skin condition.
I have these same symptoms and I would have to say it also started around the age of 24 and i am now 26 and have found no solutions either by word of mouth or by the Dermatologist. Would like to know if you have had any luck since your post.