Tuesday, November 16, 2010

Atopic Dermatitis


Atopic dermatitis is a pruritic disease of unknown origin. It is is an inflammatory, relapsing, non-contagious and pruritic skin disorder.

The disorder is characterized by eczematous lesions, dry skin, and thickening of the skin.


Atopic dermatitis may be associated with other atopic diseases such as asthma, allergic rhinitis, urticaria, acute allergic reactions to foods.

The skin affected by atopic dermatitis reacts abnormally to irritants, food, and the environment. The skin becomes red, flaky and itchy.

It is a familial and chronic disease and the symptoms can increase or disappear with time.

Causes:

Genetics -
A family history of atopic dermatitis is often common.

Infection - The skin atopic dermatitis is colonized by S aureus. This can cause a flare of atopic dermatitis.

Hygiene - Hygiene may be a cause for atopic dermatitis.

Climate - Atopic dermatitis flares occur in different climates. Heat and cold are poorly tolerated.

Differential Diagnosis:

Contact Dermatitis - A localized rash or irritation of the skin caused by contact with a foreign substance

Lichen Simplex Chronicus- A skin disorder that leads to chronic
itching and scratching


Nummular Dermatitis - A form of eczema that is characterized by round-to-oval erythematous plaques

Psoriasis - A common skin condition that causes skin redness and
irritation

Seborrheic Dermatitis - An inflammatory skin disorder that causes scaly, flaky, itchy, red skin

Tinea Pedis - A dermatophyte infection of the soles of the feet and the interdigital spaces


Lab Studies:

Skin scraping for pathological exam may be helpful to exclude tinea pedis.

Biopsy may be helpful to show an acute, subacute, or chronic dermatitis.


Medications/Treatments:

Anti-inflammatory agents provide relief of inflammation of eczematous lesions.

Topical steroids are the mainstay of treatment

Mild topical corticosteroid - Hydrocortisone ointment 1%

Medium strength topical corticosteroid - Betamethasone valerate

Immune Modulators are medicated creams that are used for the treatment of atopic dermatitis.

Tacrolimus


Pimecrolimus 1%


Moisturizing -
Patients usually benefit from lukewarm soaks followed by the application of a moisturizer.

Other treatments -

Both hydroxyzine and diphenhydramine provide relief from itching. Antibiotics are used for the treatment with infection caused by S aureus.