Case Studies:The term “eczema” is derived from the Greek word ekzein which literally means “to boil out”. In patients with eczema where the condition flares up (“boils out”) periodically. Flares may be precipitated by irritation of the skin, infection and stress. The term “dermatitis” refers to inflammation of the skin analogous to “appendicitis”, inflammation of the appendix, “hepatitis”, inflammation of the liver, etc. The terms ‘dermatitis’ and ‘eczema’ are nowadays generally regarded as synonymous. Some authors still use the term ‘dermatitis’ to include all types of cutaneous inflammation, so that all eczema is dermatitis, but not all dermatitis is eczema. The term ‘dermatitis’, however, should be used with care, as some patients regard it as implying an occupational cause. Unfortunately, there is still no international agreement on the use of these terms. Ackerman has argued that, as the term eczema cannot be defined in a way that meets with universal approval, it should be dropped from dermatological parlance. There seems to be a consensus that the term still serves a useful purpose for the clinician. Much energy has been needlessly wasted in debating which term should be used. Geographically there is unexplained preference for one or the other. Acute eczema / dermatitis is characterized by edema, erythema, vesiculation, exudation, and, crusting. Chronic eczema / dermatitis is characterized by lichenification. Lichenification refers to thickening of the skin with exaggeration of the normal markings. Enclosed are flat-topped, shiny, quadrilateral coalescing papules. Subacute eczema / dermatitis shows features overlapping with acute and chronic eczema/ dermatitis. Lesions are commonly slightly elevated, red, brownish or purplish in color with variable scaling. Generally physicians most commonly encounter the subacute presentation of eczema / dermatitis. The commonest forms of eczema / dermatitis are atopic-, seborrheic-, primary irritant-, photoallergic-, phototoxic-, nummular-, asteatotic-, stasis-, and dyshidrotic eczema/ dermatitis. Eczema / dermatitis associated with infection (e.g. dermatophyte) or infestation (e.g. scabies), so-called “ide” reactions, are additional variants. The term “atopy” was first coined in medicine in 1923 by two allergists, Coca and Cook. They defined atopy clinically as a proclivity to develop allergic rhinitis, allergic asthma, and allergic urticaria. Patients who they considered to be atopic possessed a distinctive antibody, named by them “reagin’ or “skin sensitizing antibody” because intradermal skin tests to a variety of inhalant allergens, e.g., trees, weeds, grasses, dust, moulds, and danders, elicited wheals at sites of some injections. When Sulzberger, in the early 1930s, encountered atopic patients with skin lesions that favoured antecubital and popliteal fossae, he initially called the disorder “neurodermatitis of atopic type”, then “atopic eczema” and, finally, “atopic dermatitis”. The word “atopy” is defined as “a clinical hypersensitivity state which is subject to hereditary influences; included are hay fever, asthma, and eczema”. Atopic dermatitis, allergic rhinitis, and asthma are atopic diseases that develop on a complex genetic background, the so-called atopic diathesis. The term atopic eczema or just “eczema” is frequently used in the UK, whereas atopic dermatitis is used more in the US. The word atopic in the term atopic eczema is simply an indicator of the frequent association with atopy and the need to separate this clinical phenotype from the other forms of “eczema” such as irritant or allergic contact eczema, which have other causes and distinct patterns. The terms atopic eczema and atopic dermatitis are synonymous. The morphology, distribution and evolution of eczema / dermatitis in atopic eczema / dermatitis are highly characteristic. During the infant phase (birth to two years) red scaly lesions develop typically on the cheeks usually sparing the perioral and perinasal areas. The chin is typically involved and cheilitis is common. A small but significant number of infants develop a generalized eruption. Involvement of the scalp is not uncommon. The diaper area is often spared. Sometimes the cubital / popliteal fossae or other parts of the limbs are involved. During the childhood phase (2 – 12 years) eczema / dermatitis involves the flexural areas (i.e. the antecubital fossae and popliteal fossae) but also the neck, wrist and ankles. During the adult phase (12 years to adult) lesions involve similar areas as during the childhood phase. Additionally hand eczema / dermatitis, periocular eczema / dermatitis, and, anogenital eczema / dermatitis are common. Morphologically, lesions may be acute, subacute or chronic. Importantly, for the clinician, the diagnosis of atopic eczema / dermatitis is based on the aforementioned criteria, namely age of the patient, distribution of the rash, and, morphology of the rash. Atopic eczema is a difficult disease to define, as the clinical features are highly variable in morphology, body site and time. There is no specific diagnostic test which encompasses all people with typical eczema that can serve as a reference standard. Diagnosis is, therefore, essentially a clinical one. According to the position paper from the European Academy of Allergology and Clinical Immunology nomenclature task force, the term “Atopic eczema / dermatitis syndrome” (AEDS) should be used as the “umbrella” term to cover the different subtypes of atopic dermatitis (AD). The new nomenclature (AEDS) underlines the fact that AD is not one, single disease, but rather an aggregation of several diseases with certain clinical characteristics in common. Intrinsic AD (nonallergic AEDS = NAAEDS) fulfills the most commonly used diagnostic criteria for AD (20%). These patients have no associated respiratory diseases, such as bronchial asthma or allergic rhinitis, show normal total serum IgE levels, no specific IgE, and negative skin-prick tests to aeroallergens or foods. Extrinsic AD (allergic AEDS = AAEDS) is commonly associated with respiratory allergies such as rhinitis and asthma, a high level of serum IgE, specific IgE and positive skin-prick tests to aeroallergens or foods (80%). Immunologic differences between the IgE-associated type of AD and the nonallergic type can be found in the cell and cytokine pattern in peripheral blood and in the affected skin, and also by phenotyping characterization of epidermal dendritic cells. The current explanation of this distinction is based on differences in genetics and / or environmental conditions. The classification into AAEDS and NAAEDS at each stage of life, i.e., infancy, childhood, teenage, and adult, is essential for the allergological management of patients as to allergen avoidance, secondary allergy prevention, and immunotherapy. The risk of an “atopy march” is significantly lower in children with the NAAEDS. The subdivision of allergic vs nonallergic atopic dermatitis is currently controversial. Cases may transform from one type to the other. This division may not be applicable to adults. A major development in describing the main clinical features of atopic eczema was the Hanifin and Rajka diagnostic criteria (1980). These criteria provide some degree of confidence that researchers in clinical trials are referring to a similar disease when using these features. These criteria were developed on the basis of consensus, and their validity and repeatability is unknown in relation to physician’s diagnosis. Some of the 30 or minor features have since been shown not to be associated with atopic eczema, and many of the terms, which are poorly defined, probably mean something only to dermatologists. Scientifically developed refinements of the Hanifin and Rajka diagnostic criteria, mainly for epidemiological studies, have been developed by a UK working party, and these criteria have been widely used throughout the world. These are shown in Box X. It is quite possible that there are distinct subsets of atopic eczema, for example those cases associated with atopy and those who have severe disease with recurrent infections. Until the exact genetic and causative agents are known, it is wiser to consider the clinical disease as one condition. Perhaps sensitivity analyses should be done within clinical trials or those who are thought to represent distinct subsets, for example those who are definitely atopic with raised circulating IgE to allergens, and those with severe disease and associated asthma DefinitionsAtopy = clinically defined atopy is a proclivity to develop allergic rhinitis, allergic asthma, and allergic urticaria. Patients posses a distinctive skin sensitizing antibody, (“reagin”). Intradermal skin tests to a variety of inhalant allergens, e.g., trees, weeds, grasses, dust, molds, and danders, are positive.
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