B14 Exogenous eczema hand out - funlivestreaming.com

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Exogenous eczema

Pranee Svetvilas, MD. Somdech phra Debaratana Medical Centre, Division of Dermatology

Ramathibodi Hospital, Mahidol University

Eczema

Endogenous Exogenous

Exogenous eczema or Contact dermatitis

The inflammation of the skin induced by external agents

Outlines

• Irritant contact dermatitis

• Allergic contact dermatitis

• Photo contact dermatitis

Contact dermatitis

Irritant contact dermatitis (80%) • Direct damage of epidermal cells to various substances

• Can occurred to anyone

Allergic contact dermatitis (20%) • Delayed type IV hypersensitivity to external substances (allergens)

• Only occurs in susceptible individuals who have been sensitized

ACD and ICD may co‐exist in the same patient

ICD ACD

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Irritant contact dermatitis

ICD

Introduction

• Nonspecific, nonallergic response of the skin • Direct damage to the stratum corneum by chemicals or physical agents

• Occurs faster than the skin is able to repair itself

• Can be acute or chronic • Anyone can develop ICD • Well‐demarcated, typically confined to the area of contact with the irritant

• Most common cause of hand eczema

Mechanisms of ICD:

• Disruption of epidermal barrier

• Damage keratinocyte cell membranes

• Cytotoxic effect on keratinocytes

• Cytokine released from keratinocytes

• Activation of innate immunity

Clin Rev Allergy Immunol. 2019 Feb;56(1):99–109.

The irritants

• Chemical agents • Alkaline and acid solutions, organic solvents, tensides, croton oil

• Physical agents • UV radiation, x‐rays, other ionizing radiation, laser rays, heat, cold and mechanical factors

• Food stuffs • Asparagus, mustard, fruit juices

• Plants • Agave, anemones, many others

• Chemical warfare agents

Acta Clin Croat. 2018 Dec;57(4):713‐20.

Common irritants

Detergents Surfactants

Disinfectants, antiseptics

Cosmetics

Dusts Water and

Wet work

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Water and wet work

Contact Dermatitis. 2011 Jul;65(1):3‐12.

The criteria for wet work are loosely defined, and include:

(1) Hands regularly in a wet environment for > 2 h per day

(2) Frequent hand washing (> 20 times/day)

(3) Use of hand disinfectants 20 times in a working day

(4) Use of protective gloves for > 2 h per day or change of gloves > 20 times/day

High risk occupations of ICD

• Medical personnel

• Hairdressers • Metalworkers

• Food worker • Construction and cement workers

J Am Acad Dermatol. 2020 Dec;83(6):1730‐7

Predisposing Factors‐ ICD

The Host

• Age: elderly patients, children

• Sex: women

• Body region: face, dorsal aspect of hands, and finger webs

• Atopy

The Irritant

• The nature of the irritant

• Amount of exposure

• Concentration

• Duration

• Repetition

The Environment

• Temperature

• Airflow

• Humidity

• Occlusion

Atopic dermatitis

• Filaggrin mutations

• Early‐onset dermatitis

• Greater reactivity to the irritant

• Flexural areas develop frictional irritant dermatitis

• Leads to allergic contact dermatitis

Lancet. 2016;387(10023):1109‐22.

Clinical features

• Acute ICD • Contact with a strong acid or alkali

• Mimics a chemical burn • Erythema, blisters, pustules, hemorrhage, crusts, scales, erosions and ulcers

• Pruritus or pain • Sharply bordered in the areas of contact

• Chronic ICD • Most common type • Repetitive exposure to a weak or marginal irritant over years

• Poorly defined erythematous scaly patches, dryness of skin, lichenification and desquamation

Acta Clin Croat. 2018 Dec;57(4):713‐20.

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Flexural accentuation

• Important sign of irritant dermatitis

• Common areas for irritant dermatitis are folds • Eyelid, neck

• Antecubital fossae, volar wrist

• Finger webs and creases

• Intertriginous folds

Diaper rash • Common example of irritant dermatitis

• Occur with wet‐to‐dry cycles, irritation from stool

• Decreased with the use of disposable diapers • Superabsorbent

• Prevent hyperhydration of the skin

Pediatr Dermatol. 2018 Mar;35 Suppl 1:s10‐s18.

Pustular and Acneiform Irritant Contact Dermatitis

• Workers in the mechanical industry due to contact with cutting or grinding oils

Bolognia, J.(2018) Dermatology. Philadelphia: Elsevier Saunders.

Management

• Identification and avoidance of the underlying cause • Use of personal protective equipment

Management

Topical treatment

• Regular use of emollients

• Topical corticosteroids • Topical tacrolimus or pimecrolimus

Systemic treatment

• Acute phase or severe • Systemic corticosteroids:

• Severe • PUVA, NBUVB

• Systemic immunomodulators • Methotrexate, cyclosporine and targeted biologic therapy

Prognosis

Hardening

• ICD resolves spontaneously even with continuous exposure • The exact mechanisms are still unclear

Poor prognosis

• Previous history of atopy • Female gender

• Presence of allergic contact dermatitis

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Allergic contact dermatitis

ACD


• T‐cell–mediated delayed‐type hypersensitivity reaction

• Occurs after skin exposure to a specific hapten in previously sensitized individuals

IL‐10 T reg

IL10 IL‐10 T reg

IL10

Clinical features

• A pruritic, eczematous dermatitis

• Localized to the primary site of allergen exposure

• Geometric, linear, or focal patterns of involvement‐ suggestive of exogenous etiology

• Acute/ subacute/ chronic phase • Can develop disseminated eczema (autosensitization dermatitis)

Wolff, K., Goldsmith, L., Katz, S., Gilchrest, B., Paller, AS.,& Leffell, D. (2019). Fitzpatrick's Dermatology in General Medicine, 8th Ed. New York: McGraw-Hill.

Common allergens


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Nickel • Most common allergen (20% of population)

• Strong silver‐colored metal

• Sources to consider • Jewelry/Everyday products

• Oral Ingestion: nut, grain, chocolate, fish, tap water

• Medical devices

• Concomitant reactions to nickel and cobalt

• Sweating can increase the amount of metal leached from a product

To prevent development of nickel sensitivity

• Regulated the amount of nickel that may be released from objects with direct and prolonged skin contact to < 0.2 μg nickel/cm2/week

Dimethylglyoxime test

• Identifies objects that release nickel using a pink color indicator • 1% Dimethylglyoxime + 10%AlOH2

• Detect nickel conc. 1:10,000

Fragrance

• 4% of the population are allergic to fragrances • Found in

• Personal care products

• Scents and flavorings for foods and drinks

• Masking fragrance • Used to mask an unpleasant odor

• Labeled as ‘unscented’

Fragrance • Fragrance mix I

• Fragrance mix II

• Myroxylon pereirae (balsam of Peru)


Preservatives

• Action against micro‐ organisms • Anti‐ fungal

• Anti‐ bacterial

• Prevention of degradation of products • Antioxidants

Methylisothiazolinone allergy

Caused by

• 75% cosmetic products (preservatives)

• 25% paints, cutting oils, etc.

• Allergen of the year 2013

Dermatitis. 2015 Mar‐Apr;26(2):99‐102. Puangpet P1, Chawarung A, McFadden JP.

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• MI was combined with methylchloroisothiazolinone (MCI) in a ratio of 3 : 1 in rinse‐off products, and its concentration was <3.75 ppm.

Methylisothiazolinone (MI)

• Wipes

• Lotions

• Liquid soaps

• Shampoos

• Deodorants

• Glue in slime

Parabens (non)allergen of the year

• Parahydroxybenzoates

• Used safely in cosmetic products, pharmaceuticals, and foods for more than 70 years

• Inexpensive, effective biocides

• Very rare cosmetic sensitizers

Dermatitis. 2019 Jan;30(1):3–31.

Dermatitis. 2019 Jan;30(1):3–31.

Neomycin Sulfate

• Antibiotic (topical>systemic)

• Found in over‐the‐counter (OTC) preparations • Antibacterial ointments, hemorrhoid creams, and otic and ophthalmic preparations

• Co‐reactivity is commonly observed with neomycin and bacitracin.

Paraphenylenediamine (PPD)

• Most commonly used permanent hair colorant

• Involves primarily the forehead, neck and scalp

• Once fully oxidized, the disperse dye is no longer allergenic • Also found in some temporary tattoos

Ann Dermatol Venereol. Aug‐Sep 2018;145(8‐9)

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2‐Methoxymethyl‐ para ‐phenylenediamine (me‐ PPD)

• A less allergenic alternative for para ‐phenylenediamine.

• An alternative hair dye for primary prevention

• Cross‐elicitation responses can occur in PPD‐allergic subjects

Nail cosmetics (Acrylates)

• Nail aesthetics • Dental aesthetics

• Hair/eyelash extension (glue)

• Other cosmetic products

ACRYLATES 0.1% pet Esters or salts of acrylic acid

METHACRYLATES 2% pet Esters or salts of methacrylic acid

CYANOACRYLATES 10% pet Esters or salts of cyanoacrylic acid

Poly/ mono

Cross‐linked alkyl acrylate polymers

cyanoacrylates do not cross‐react with (meth)acrylates

Nail cosmetics


• Periungual • Fingers‐ PULPITIS • Hands‐ palms

• Wrist/ forearms

• “airborne”

Occupational (60%)

Consumers


• Pain/paresthesia • Onycholysis • Nail fragility/ dystrophy/ nail loss • Subungual hyperkeratosis

Contact Dermatitis. 2016 Feb;74(2):120‐2

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Acrylates • Medical dressings

• Incontinence pads • Surgical glues • Diabetic devices • Other devices

Contact Dermatitis. 2017 Dec;77(6):367‐373. Contact Dermatitis. 2018 Apr 10. doi: 10.1111/cod.12995.

Patch Testing

• The GOLD STANDARD for diagnosing allergic contact dermatitis.

• Diagnosing contact allergy– a delayed type of hypersensitivity (type IV reaction)

• Do not test pregnant women

Indications for patch testing

• Cases of contact dermatitis

• Other types of eczema and dermatoses • superimposed contact allergy is suspected

• recurrent and nonresponsive to treatment

• “Predictive testing” of alternative products such as gloves, skin care products, medicaments

• Tests delivered in ready‐to‐use packages • US FDA approved • Panels with pre‐impregnated allergens: 35 allergens

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Irritant reactions

• Wrinkling

• Desquamation

• Pustule • Poral reaction‐ Cobalt • Edge effect

Management

• Identification and avoidance of the underlying cause

• Use of personal protective equipment

Management

Topical treatment

• Regular use of emollients

• Topical corticosteroids • Topical tacrolimus or pimecrolimus

Systemic treatment

• Acute phase or severe • Systemic corticosteroids:

• Severe • PUVA, NBUVB

• Systemic immunomodulators • Methotrexate, cyclosporine and targeted biologic therapy

Photocontact dermatitis

UV + Chemical agents Photocontact dermatitis Nutrients . 2018 Mar 24;10(4):403.

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Exogenous photosensitivity

Phototoxicity

• Direct tissue and cellular injury following UVR‐induced activation of a phototoxic agent

• Exaggerated sunburn‐like reaction

• Usually caused by medications

• Can be induced in any individual

Photoallergy

• Delayed‐type hypersensitivity response

• Presents with eczematous lesions

• Most commonly related to topical photoallergens

• Confirmed by photopatch testing


Interpretation of photopatch tests

Non radiated with UVA Radiated with UVA

‐ + Photo ACD

+ ++ Photo ACD + ACD

+ + ACD


Phytophotodermatitis • Phototoxic reaction • After skin contact with plants containing furocoumarins plus subsequent exposure to UVA in sunlight.

• Parsley, celery, lime, yarrow, and fig

• Linear postinflammatory hyperpigmentation is a classic finding.

Conclusions

Irritant contact dermatitis • Direct damage of epidermal cells to various substances

• Can occurred to anyone

Allergic contact dermatitis • Delayed type IV hypersensitivity to external substances (allergens)

• Only occurs in susceptible individuals who have been sensitized

• Diagnosed by patch testing

Photocontact dermatitis • Both UV + chemical induced skin rash

• Diagnose by photopatch testing

B14 Exogenous eczema hand out - funlivestreaming.com

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