In the Name of GodContact Dermatitis( Exogenous )

Milad Ghasrifard 8999001036

Content ICD

Predisposing Factor Pathogenesis Diagnose Treatment

ACD Pathogenesis Diagnose Prevalence Treatment

ICDDefinition Contact dermatitis is an eczematous dermatitis caused by

exposure to substances in the environment. Environmental factors including concentration, mechanical

pressure, temperature, humidity, pH, and duration of contact The most commonly affected sites are exposed areas such as the

hands and the face, with hand involvement in approximately 80% of patients and face involvement in 10%

ICDPredisposing Factor Age, race, sex, pre-existing skin disease Patients with darkly pigmented skin seem to be more resistant to

irritant reactions The most commonly affected sites are exposed areas such as the

hands and the face, with hand involvement in approximately 80% of patients and face involvement in 10%

ICDPathogenesis Acute Phase

Influence penetrating through the barrier Minor injury The release of inflammatory mediators

Chronic Phase Damage to lipids in the stratum The loss of adhesion Chorneocyte Desquomation Increased water through the epidermis

ICDDiagnosis Base Of History And Physical Exam

Point : Patch Test Is Negative

ICDTreatment1. Avoid exposure to irritants by using protective

equipment, such as gloves2. Topical steroids are used to initially control

inflammation3. Moisturizers used generously and frequently increase

skin hydration, and their lipid component improves the damaged skin barrier

4. Cool compresses are used for acute inflammation. They suppress vesiculation and decrease inflammation.

ACDDefinition ACD defined as an inflammatory process affecting skin ( Epidermal

Layer )

ACDSymptoms

Typical Symptom is Eczematic Prurient Rash With Fine border Acute

Bright red edematous skin May have clear fluid-filled vesicles or bullae

Chronic Scaling , skin fissuring , and lichenification but only minimal edema.

Reaction Occur in Site of Allergen ContactACD be Change to systemic Eczema

ACDPathogenesis Sensitization phase

Hapten penetrates skin Biochemically transformed by epidermal enzymatic processes Conjugated with a carrier protein to become immunogenic Captured by antigen presenting cells (APCs), particularly Langherans cells Processed, bound to class II MHC molecules, and exposed on cell surface Cytokines produced by keratinocytes and APCs Langherans cells migrate towards locoregional lymph nodes Specific effector and memory T lymphocytes selected and clonally

proliferated  Enter bloodstream and reaches to skin and subject is sensitized to hapten.

ACDPathogenesis Elicitation phase

New contact penetration of skin Substance undergoes chemical changes Recognized and processed by Langherans cells Specific T lymphocytes are recalled at skin level and, together with

keratinocytes, release numerous cytokines Amplify inflammatory response Give rise to skin damage

ACDDiagnosis History And Physical Exam Patch Test

ACDOther Allergen

Nickel sulfate (various metal alloys) Potassium dichromate (cements, household cleaners), Chromate (leather products) Lanolin (emollients) Formaldehyde Ethylenediamine (dyes, medications) Mercaptobenzothiazole (rubbers) Thiram (fungicides) Paraphenylenediamine (Hair dyes, Henna, photographic chemicals) Balsam of peru (fragrance) Fragrance Cobalt Chloride

Nicle Dermatit

ACDTreatment First Line Identify and remove the etiologic agent Wet dressings with cloths soaked in Burow's solution changed every 2 to

3 hours just for 1-3 first day Emollients

Emollients may be used as adjuncts to moisturize dry skin in subacute and chronic contact dermatitis

Must be Without 1. Paraben 2 . Lanolin 3 . Fragrance Antihistamines Topical glucocorticoid ointments/gels (classes I to III) for early

nonbullous lesions Systemic glucocorticoids: Severe & Exudative lesions

Prednisone, initial 70 mg (adults), tapering by 5 to 10 mg/d over a 1- to 2-week period

ACDTreatment Secound Line PhotoTherapy

PUVA Azathioprine & Cyclosporine

DDx Dermatitis

Atopic Dermatitis Sebboric Dermatitis Psoriasis Fungal Infection

Annular Asymmetrical KOH + Patch Test -

PLE History Of Photoallergen Photo patch + Site of Light Exposure