【正文】 Eczema and Dermatitis 濕疹與皮炎 中山一院皮膚性病學(xué)教研室 章星琪 Xingqi Zhang. , . ? Contact Dermatitis ? Atopic Dermatitis ? Eczema ? Clinical features* ? Management* Eczema/dermatitis ? The terms are interchangeable – Denoting a polymorphic inflammatory reaction pattern involving the epidermis and dermis. – There are many etiologies and a wide range of clinical findings. ? Polymorphic inflammatory reaction – Acute: pruritus, erythema, and vesiculation。 – chronic: pruritus, xerosis, lichenification, hyperkeratosis, 177。 fissuring. ? Pathogenesis not pletely understood – Most of them caused by hypersensitivity – Insults may not be found Classification of Eczema/dermatitis ? Contact Dermatitis 接觸性 ? Atopic Dermatitis 特應(yīng)性 ? Eczema – Classical 經(jīng)典性 ? Site specific – Seboehrric Dermatitis/eczema 脂溢性 – Asteatotic Eczema 乏脂性 – Static Eczema 郁積性 – Autosensitized eczema自身敏感性 – Nummular Eczema 錢幣型 Contact Dermatitis ? Acute or chronic inflammatory reactions to substances that e in contact with the skin. – Irritant contact dermatitis (ICD) is caused by a chemical irritant – Allergic contact dermatitis (ACD) by an antigen (allergen) that elicits a type IV (cellmediated or delayed) hypersensitivity reaction. Irritant Contact Dermatitis ? ICD is caused by exposure of the skin to chemical or other physical agents that are capable of irritating the skin, acutely or chronically. – The hands are the most monly affected area – Mostly occupational accidents. ? Epidemiology – ICD is the most mon form of occupational skin disease, accounting for up to 80% of all occupational skin disorders. – Occupational Exposure – Individuals engaged in the following occupations/activities are at risk for ICD: ? housekeeping。 hairdressing。 medical, dental, and veterinary services。 cleaning。 floral arranging。 agriculture。 horticulture。 forestry。 food preparation and catering。 printing。 painting。 metal work。 mechanical engineering。 car maintenance。 construction。 fishing. Most Common Irritant/Toxic Agents ? Detergent: Soaps, waterless hand cleaners ? Acids and alkalis: hydrofluoric acid, cement, chromic acid, phosphorus, ethylene oxide, phenol, metal salts. ? Industrial solvents: coal tar solvents, petroleum, chlorinated hydrocarbons, alcohol solvents, ethylene glycol ether, turpentine, ethyl ether, acetone, carbon dioxide, DMSO, dioxane, styrene. ? Plants: Euphorbiaceae (spurges, crotons, poinsettias, machneel tree). Racunculaceae (buttercup), Cruciferae (black mustard), Urticaceae (tles), Solanaceae (pepper, capsaicin), Opuntia (prickly pear). ? Others: fiberglass, wool, rough synthetic clothing, fireretardant fabrics, NCR paper. Irritant Contact Dermatitis industrial solvent massive blistering on the palm. This airport worker had repeatedly spilled kerosene over his hands and developed acute bullous and extremely painful ICD 24 h later. Chronic irritant contact dermatitis in a housewife. There is erythema, hyperkeratosis, scaling, and fissures particularly on the finger tips in a patient with an atopic background. subacute/chronic Erythema, edema, scaling, fissuring, crusting of the palmar aspect of the hand and wrist。 a housewife, is atopic and has ignored instructions to wear gloves during work in the kitchen and to use lubricating creams. ICD ? Clinical features – Any one can have – With clear border – Resolved after removing of causative agent – Usually acute and can have bulla Allergen Contact Dermatitis Eczematous dermatitis due to reexposure to a substance to which the individual is sensitized. ? Epidemiology – Frequent: Accounts for 7% of occupationally related illnesses in the United States. – Occupation: One of the most important causes of disability in industry. ? Pathogenesis – A classic, delayed, cellmediated hypersensitivity reaction ? DTH, CMI – Contact allergens are diverse and range from metal sa