Eczema is a type of dermatitis where there is an inflammation on the epidermis (outermost layer) of the skin. The condition is marked by itchy, erythematous and crusting patches on the surface of the skin. Generally a chromic dermatitis is referred as eczema. The basis of eczema has been attributed to a dysfunction of the immune system. The common symptoms of eczema include swelling of the skin, itching, dryness, blistering and cracking of the epidermis of skin. Eczema may be classified according to location, morphology or aetiology. For example eczema can occur in hands, may be discoid in shape or may have a possible cause like varicose eczema. Eczema can be allergic or non allergic in nature. Based on this, The European Academy of Allergology and Clinical Immunology has classified allergic eczemas into atopic and allergic contact eczemas.
Eczemas can present in various forms of dermatitis. In Xerotic eczema the skin becomes so dry that it gets cracked down and represents eczema of serious nature. This form is induced by cold weather and occurs in older people. Dyshidrosis or housewife’s eczema occurs mainly on palms, soles as tiny bumps or vesicles and occurs in warm weather. Discoid eczema has a microbial basis and is marked by round spots of oozing found often in lower legs. Venous eczema or static dermatitis occurs in individuals having compromised circulation in conditions like varicose veins or deep vein thrombosis. Auto- eczema occurs when there is an allergic reaction to an infection with parasites, fungi or bacteria or viruses. The disease is curable and the inflammation occurs at a site distant from the site of infection. Eczema herpeticum represents eczema that occurs from viruses and eczema from underlying disease like lymphoma may also occur.
Atopic dermatitis is a type of allergic eczema that is attributed to hereditary occurrence. This form of dermatitis is often manifested in persons, whose family members suffers from asthma. The symptoms of atopic dermatitis includes itchy rash specifically on head, scalp, inside of elbows, behind knees and buttocks. This form of dermatitis is prevalent in developed countries and has been on the rise. Hence Atopic dermatitis is a sub class of eczema, but all eczema is not forms of atopic dermatitis.
The basis of eczema or atopic dermatitis can have a environmental or genetic basis. The hygiene hypothesis speculates that eczema develops from exposure to unusually clean environments, from birth. This cleanliness may initiate inappropriate immune response from birth leading to an increased probability of eczema. Various genes like filaggrin, OVOL1, ACTL9 and IL4-KIF3A has been associated with increased probability of eczema.
Management of eczema is mainly done through application of moisturizers to prevent the dryness of the skin and reducing the brittleness. Corticosteroids are also recommended in suppressing the symptoms of eczema in flare up cases. Immunosuppressant like tacrolimus and pimecrolimus have shown encouraging results in preference to steroids specifically on attributes like toleration profile for the management of eczema. A brief comparison of eczema and atopic dermatitis is represented below:
Eczema | Atopic Dermatitis | |
Description | Dermatitis of any origin allergic or non allergic. Includes contact allergic dermatitis and atopic dermatitis too. | Specific type of dermatitis having a definite hereditary basis. Does not include non allergic eczema or contact allergic eczema. |
Symptoms | Varied according to the types of eczema and in general is marked by itchy skin, cracking skin and erythematous swelling | itchy rash specifically on head, scalp, inside of elbows, behind knees and buttocks |
Demography | Prevalence all across the globe | Mainly in developed countries |
Age group affected | Child to elder individuals | Children |
Basis of Disease | Environmental and Genetic | Mainly Genetic |
Types | Varicose eczema, Xerotic eczema and others | Only single type |
Causative agent | Viral, bacteria and fungi | Idiopathic |
Management | Moisturizers, steroids and immunosuppressant | Moisturizers mainly |