exogenous dermatitis contain Allergic & Irritant Dermatitis

1. In the Name of God
Contact Dermatitis
( Exogenous )
Milad Ghasrifard 8999001036

2. Content
ICD
Predisposing Factor
Pathogenesis
Diagnose
Treatment
ACD
Pathogenesis
Diagnose
Prevalence
Treatment

3. ICD
Definition
 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%

4. ICD
Predisposing 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%

5. ICD
Pathogenesis
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

6. ICD
Diagnosis
 Base Of History And Physical Exam
 Point : Patch Test Is Negative

7. ICD
Treatment
1. Avoid exposure to irritants by using protective equipment,
such as gloves
2. Topical steroids are used to initially control inflammation
3. 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.

8. ACD
Definition
 ACD defined as an inflammatory process affecting skin ( Epidermal Layer )

9. ACD
Symptoms
 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 Contact
 ACD be Change to systemic Eczema

10. ACD
Pathogenesis
 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.

11. ACD
Pathogenesis
 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

13. ACD
Diagnosis
 History And Physical Exam
 Patch Test

15. ACD
Other 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

16. Nicle Dermatit

17. ACD
Treatment 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

18. ACD
Treatment Secound Line
 PhotoTherapy
 PUVA
 Azathioprine & Cyclosporine

19. DDx Dermatitis
 Atopic Dermatitis
 Sebboric Dermatitis
 Psoriasis
 Fungal Infection
 Annular
 Asymmetrical
 KOH +
 Patch Test -
 PLE
 History Of Photoallergen
 Photo patch +
 Site of Light Exposure