My four year old has always had sensitive skin. At times, she breaks out with a flat pink/red dry looking rash clustered mostly on her face, behind her knees, legs and in the folds of her arms on the front side of her elbows. Could it be pediatric eczema?

Eczema. It definitely sounds like eczema. Use dove soap when bathing, a thick moisturizer 2-3 times daily, and 1% Hydrocortisone twice daily for 1 week to any itchy areas.
This . This does sound like possibly atopic dermatitis, which is common form of eczema seen in children. I would consider using cerave hydrating cleanser (gentle, soapless cleanser), cerave cream to moisturize the skin everyday, and a possible trip to the dermatologist for good treatment options. For my patients, i often combine the above therapy with prescriptions such as Protopic ointment, desonide ointment, or Cutivate Ointment with pretty good success. I hope that helps! take a look at the link below for a picture of eczema that probably is similar to what you are talking about.
There . There are many options available to treat eczema. These include moisturizers (vanicream, cetaphil restoraderm, cerave to name a few), topical steroids (both over-the-counter and prescription), and calcinuerin inhibitors (pimecrolimus and tacrolimus). In general the mainstay of routine treatment should be with moisturizers and using as needed topical steroids. There is potential for skin lightening and thinning of the skin with topical steroids if used for long-term therapy or with the use of potent topical steroids. Food allergy can be involved in some cases of moderate-severe eczema. Other strategies include soak and seal wraps/dressings, bleach baths and other hydrating options. Would recommend you see your local provider to find out more information about these. It is also common for patients who have eczema to develop allergic rhinitis as well as asthma. I think that it is important to have your primary care provider/dermatologist/allergist work together to help provide the best results possible.
Rash. Rashes are hard to diagnose without seeing them. If it is eczema the key to eczema is moisturizing (more then you think is humanly possible) and controlling the itch if she's itchy. Here's a link to great information on eczema: http://eczemacenter.Org/familyresources.Htm.