These characteristically have a superficial perivascular inflammatory infiltrate and can be classified by type of cell infiltrate:Lymphocytic (most common)
Lymphoeosinophilic
Lymphoplasmacytic
Mast cell
Lymphohistiocytic
Neutrophilic

Terminology
There are several types of dermatitis including atopic dermatitis, contact dermatitis, stasis dermatitis and seborrhoeic dermatitis. Many authors use the terms dermatitis and eczema synonymously, and various dictionaries that treat the terms as differentiable nonetheless do not provide explicit criteria for differentiating them, as the aspects of inflammation, pruritus, and either exogenous or endogenous provoking agent all can apply to either term, and thus autoimmune components are not excluded from either. Others use the term eczema to specifically mean atopic dermatitis. Atopic dermatitis is also known as atopic eczema. In some languages, dermatitis and eczema mean the same thing, while in other languages dermatitis implies an acute condition and eczema a chronic one. Common types
Diagnosis of types may be indicated by codes defined according to International Statistical Classification of Diseases and Related Health Problems (ICD). Atopic
Atopic dermatitis is an allergic disease believed to have a hereditary component and often runs in families whose members have asthma. Itchy rash is particularly noticeable on the head and scalp, neck, inside of elbows, behind knees, and buttocks. It is very common in developed countries and rising. Irritant contact dermatitis is sometimes misdiagnosed as atopic dermatitis. Stress can cause atopic dermatitis to worsen.
In severe cases, oral or injectable corticosteroids may be used. While these usually bring about rapid improvements, they have greater side effects. Long term use of topical steroids may result in skin atrophy, stria, telangiectasia. Their use on delicate skin (face or groin) is therefore typically with caution. They are, however, generally well tolerated. Red burning skin, where the skin turns red upon stopping steroid use, has been reported among adults who use topical steroids at least daily for more than a year. Antihistamines
There is little evidence supporting the use of antihistamine medications for the relief of dermatitis. Sedative antihistamines, such as diphenhydramine, may be useful in those who are unable to sleep due to eczema. Second generation antihistamines have minimal evidence of benefit. Of the second generation antihistamines studied, fexofenadine is the only one to show evidence of improvement in itching with minimal side effects. Immunosuppressants
Topical immunosuppressants like pimecrolimus and tacrolimus may be better in the short term and appear equal to steroids after a year of use. Their use is reasonable in those who do not respond to or are not tolerant of steroids. Treatments are typically recommended for short or fixed periods of time rather than indefinitely. Tacrolimus 0.1% has generally proved more effective than pimecrolimus, and equal in effect to mid-potency topical steroids. There is no link to increased risk of cancer from topical use of 1% pimecrolimus cream.When eczema is severe and does not respond to other forms of treatment, systemic immunosuppressants are sometimes used.