Dermatitis is a general medical term referring to inflammation of the skin. Dermatitis comes in many forms, although it usually involves skin that is swollen, irritated, or other related symptoms. Some cases are simply known as rashes. Most types of dermatitis also share the distinction of coming by way of allergic reaction, although the allergens themselves may be unique.

Certain dermatitis types include:

Atopic dermatitis
Contact dermatitis
Cradle cap
Dandruff
Diaper rash
Dyshidrosis (dyshidrotic eczema)
Eczema
Erythroderma
Lichen simplex chronicus
Nummular dermatitis (discoid dermatitis)
Pityriasis alba
Prurigo nodularis
Pruritis ani
Seborrheic dermatitis
Stasis dermatitis (varicose eczema)
Toxicodendron dermatitis (from urushiol)


Causes of dermatitis vary depending upon type. With that in consideration, some of the potential dermatitis causes include:

Allergen contact (allergies)
Dry skin
Immune system dysfunction
Irritant contact
Oily hair
Oily skin
Poor circulation (legs)
Tissue fluid accumulation

Likewise, different types and cases of dermatitis may have differing symptoms. Some frequent symptoms experienced in dermatitis include:

Blisters
Bumps
Crusty skin
Irritation
Itching
Lesions
Rash
Redness
Scales
Swelling