EXOGENOUS ECZEMA CONTACT DERMATITIS DR ANWAR ISSA 25102018

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). • • Examples of ICD are house wife dermatitis & napkin dermatitis. • Ddx : thermal burn , ACD & Atopic dermatitis /treatment : primary avoidance of irritant. ICD; can acute with erythema, oozing, vesiculation or even erosions in sever cases or chronic with dryness , scale and painful fissure. ICD; more common in persons with dry skin , old people, industrial workers and atopic patients.

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 1. 2. Exogenous : irritant contact dermatitis & allergic contact dermatitis. 3. Infection : tinea or superimposed bacterial infection e. g. S aureus. Endogenous : psoriasis, atopic dermatitis & others like dyshidrotic eczema. • 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 4 hypersensitive 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 : 1. Ear lobe dermatitis ; nickel ( most common allergens)allergy due to earrings. 2. Cement dermatitis; potassium dichromate allergy. 3. Shoe dermatitis ; leather or rubber allergy. 4. Eyelid dermatitis ; nail varnish, local medication, cosmetics &air born demerititis 5. 6. 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 : 1. 2. 3. 4. + : erythema &papule (weak). ++ : erythema , papules & vesicles (strong) +++ : spreading bullous reaction. - : negative reaction.

PATCH TEST

ALLERGIC CONTACT DERMATITIS • Treatment of allergic contact dermatitis: 1. 2. 3. 4. 5. 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.

• Irritant contact dermatitis • Allergic contact dermatitis • examples • Water, soap, acids, solvents& • Nickel, fragrance, hair dye. detergents (many) • (few) • Distribution of reaction • localized • May spread beyond area of maximal contact & may become systemic • Concentration of agent needed to elicit reaction • high • low • Time course • Immediate to late • Sensitization in 2 weeks, next elicitation need 48 -72 hr. • Immunology • Population • Nonspecific • All • Specific type 4 hypersensitive reaction. • Genetically predisposed persons • Diagnostic test • None • Patch 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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