Exogenous eczema Contact dermatitis - PowerPoint Presentation

Slide1

Exogenous eczema

Contact dermatitis

Dr. Anwar Issa

25/10/2018

Irritant contact dermatitis

ICD

; is localized non immunological cutaneous inflammatory reaction , secondary to direct contact toxin effects e.g. acids & alkali or cumulative exposure to the irritant substance e.g. detergent ,solvents ,kerosene ,soap and water .

ICD

; account about 80% of all contact dermatitis ( 20% allergic contact dermatitis).

ICD

; can acute with erythema, oozing, vesiculation or even erosions in sever cases or chronic with dryness ,scale and painful fissure .

Examples of ICD are house wife dermatitis & napkin dermatitis.

ICD

; more common in persons with dry skin ,old people, industrial workers and atopic patients.

Ddx

: thermal burn ,ACD & Atopic dermatitis /treatment :primary avoidance of irritant.

Irritant contact dermatitis

house wife dermatitis

; usually affect both hand ,but sometimes only dominant hand affected , with chronic eczematous lesion on the palmer surface even painful fissures ,due to exposure to the detergent &excessive use of soap and water.

House wife dermatitis can affected planter surfaces of feet.

Complication ;

chronic irritation lead to loss of cuticle of the fingers nail which provide portal entry to the microorganisms e.g. bacteria cause acute paranochyia(painful) or fungi cause chronic paranochyia (painless).

Treatment: avoidance of irritation by regular use of hypoallergic gloves and emollient ,topical corticosteroids cream only for short time& treatment of infection.

Other namoculature mechanical hand or dirty hand

House wife dermatitis

DDx of hand eczema

Exogenous : irritant contact dermatitis & allergic contact dermatitis .

Endogenous : psoriasis, atopic dermatitis & others like dyshidrotic eczema.

Infection : tinea or superimposed bacterial infection e.g. S aureus.

How can differentiate between them ?

paranochyia

Irritant contact dermatitis

Napkin dermatitis

; common type of irritant dermatitis affect about 50% of infant , due to dampness ,irritation effect of urine and feces with prolong use of diaper (occlusion, mosturization and irritation).

C/F; red ,glazed erythema with erosions , even pseudoverrucous lesion in the diaper area well demarcated ,favor convex surface (skin folds are spared). why?

Complication; coexisting candidiasis is common .

DDx candidiasis, allergic CD, psoriasis, seborrheic dermatitis& atopic dermatitis.

Treatment: frequent change of diaper ,use of highly absorbable one ,regular use of barrier cream with each diaper change e.g. zinc oxide cream ,topical corticosteroids& topical antifungal creams (for candidiasis).

Allergic contact dermatitis

ACD : less common type of contact dermatitis ,account about 20% of CD ,is immunologically mediated cutaneous inflammatory reaction due to exposure to certain type of allergens.

ACD ; occurs at site of contact allergens and may extended to other site .

ACD: characterized by itchy erythema with acute vesiculation or

bullea

and oozing.

ACD : local and systemic type .

ACD ; its type 4hypersensitive reaction ,mediated by T lymphocytes.

ACD ; diagnosis by Patch test .

ACD; need sensitization before develop so occurs after 2-6 week from first exposure to the allergens.

Allergic contact dermatitis

Examples of ACD :

Ear lobe dermatitis ;nickel ( most common allergens)allergy due to earrings.

Cement dermatitis; potassium dichromate allergy.

Shoe dermatitis ; leather or rubber allergy .

Eyelid dermatitis ;nail varnish, local medication, cosmetics &air born

demerititis

Hair dye dermatitis ; paraphenelydiamine

PPD.

Phytophotodermatitis; plant dermatitis; e.g. poison of ivy, oak &sumac

Allergic contact dermatitis

Example of allergic contact dermatitis to the leather

ACD

EXAMPLE OF ACD IS

PHYTOPHOTODERMATITIS

Allergic contact dermatitis

Patch test

; is confirmatory not diagnostic test in ACD.

Its depend on immunological reaction to the applied allergens ( delayed type hypersensitive reaction T cell mediated reaction).

Technique ;fixing allergens to the patient's back using scanpor tape , then removal of tape after 48 -72

hr

, marking allergens upon removal of scanpor tape.

Grading :

+ :erythema &papule (weak).

++ : erythema ,papules & vesicles (strong)

+++ : spreading bullous reaction.

- : negative reaction.

Patch test

Allergic contact dermatitis

Treatment of allergic contact dermatitis

:

Avoid allergens .

Topical corticosteroid creams.

Systemic antihistamine to itching .

Treatment coexisting infections with topical and systemic antibiotic.

Sever cases and systemic ACD treat with short course of systemic steroids.

Allergic contact dermatitis

Irritant contact dermatitis

Nickel, fragrance,

hair dye.

(few)

Water, soap, acids, solvents

& detergents (many)

examples

May spread beyond area of maximal contact & may become systemic

localized

Distribution

of reaction

low

high

Concentration

of agent needed to elicit reaction

Sensitization in 2 weeks, next elicitation need 48-72hr.

Immediate

to late

Time

course

Specific

type 4 hypersensitive reaction.

Genetically predisposed persons

Nonspecific

All

Immunology

Population

Patch test

None

Diagnostic test

Radiation dermatitis

Radiation dermatitis

is a side effect of external beam ionizing radiation. It is also called radiodermatitis, x-ray dermatitis, radiation skin damage or a radiation burn. Most commonly, radiation-induced dermatitis is caused by radiotherapy for underlying malignancies

.

Acute and chronic type , localized to site of irradiation .

Burn, mild pink color with itching or pigmentation .

Treatment : mild cases aloe Vera cream ( emollients) after radiotherapy sections.

Course : mild cases heal within 2-4 weeks ,sever cases need months to heal

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