There are several different types of dermatitis. The different kinds usually have in common an allergic reaction to specific allergens. The term may describe eczema, which is also called dermatitis eczema and eczematous dermatitis. An eczema diagnosis often implies atopic dermatitis (which is very common in children and teenagers) but, without proper context, may refer to any kind of dermatitis
Types of dermatitis are classified according to the cause of the condition.
Contact dermatitis is caused by an allergen or an irritating substance. Irritant contact dermatitis accounts for 80% of all cases of contact dermatitis . It  is inflammation of the skin that occurs when skin come into contact with a particular substance and causes red, itchy and scaly skin, and sometimes burning and stinging. Contact dermatitis is a type of eczema that cause dry, irritated skin. 

Atopic dermatitis is very common worldwide and increasing in prevalence. It affects males and females equally and accounts for 10%–20% of all referrals to dermatologists. The atopic dermatitis triad includes asthma, allergies (hay fever), and eczema. There is a known hereditary component of the disease, and it is seen more in some families. The hallmarks of the disease include skin rashes and itching. Individuals who live in urban areas with low humidity are more prone to develop this type of dermatitis.