I have oily skin, sometimes it veers towards combination, but generally it is oily.  However, I have eczema on my eyelids that flares up in times of stress, illness, and when I'm generally not looking after myself properly: the same goes for my lips.  I also have a nose that has decided it is dehydrated - a couple of weeks ago I could quite literally pull of skin in the same kind of way that I have done in years gone by with my eczema.
What this goes to show is that dry skin and dehydrated skin are most definitely not one and the same.  Any skin-type can be dehydrated.
There are a few products that I now keep in my skincare arsenal to aid me with these issues.
First of all, the eczema on my eyes: I try to prevent it by drinking enough water and using my holy grail eye cream - the Eucerin Aquaporin, which quite literally obliterates most of my eczema.  However, when it does flare up I use a prescription steroid - hydrocortisone - to rid myself of the condition within 1-2 applications.  It is a steroid, and as such does thin the skin, meaning I use it as little as possible, but it truly is the only thing that helps when my eyes erupt into painful redness.
In terms of lips, again, the amount of water I drink resonates directly onto my lips. I do always try and use a natural lip balm - favourites being Burt's Bees and Lanolips.
Skin always starts off with cleansing, and when my skin is dehydrated or out of balance, I get into a routine of using the Botanics Cleansing Balm, applying it to the face, and massaging it in for as long as I can stand to.  Doing this a couple of days in a row helps my skin to become radiant and supple fairly quickly.  I then tend to use a moisturising mask - this month's mask du jour is the La Roche Posay Hydraphase mask which I also use as an overnight mask, plus a plethora of serums: the best I have for dehydrated skin is the Estee Lauder Advanced Night Repair, which just has far too many positives to even mention, but trust me, EVERYONE needs a bottle of this in their lives!
The mixture of all these products generally cures any dehydration in around 2-3 days, and leaves my skin plump and healthy!
Love A.x