CONTACT DERMATITIS PATCH TEST Contact Dermatitis CD u

CONTACT DERMATITIS PATCH TEST

Contact Dermatitis (CD) u. An inflammatory skin reaction to direct contact with noxious agents in environment

Contact Dermatitis u Irritant Contact Dermatitis (ICD) u Allergic Contact Dermatitis (ACD) u Phototoxic or photoirritant contact dermatitis (PICD) u Photoallergic contact dermatitis (PACD)

Irritant Contact Dermatitis-Pathogenesis u. Exogenous Factors u. Endogenous Factors u. Sensitive Skin

Irritant Contact Dermatitis--Action u Horny layer u Cellular membranes u DNA synthesis u Epidermal metabolism u Blood vessels u Leukocytes u Mast cells

Irritant Contact Dermatitis--Types u Acute irritant dermatitis u Irritant reaction u Delayed acute irritant contact dermatitis u Cumulative irritant dermatitis u Pustular and acneiform irritant dermatitis u Mechanically induced irritant contact dermatitis u Subjective irritation

Irritant Contact Dermatitis--Morphology u Erythema, Edema, Vesicles/bullae, Papules, Dryness, Scale, Fissuring, Pustules, Comedones, Lichenification, Callus, Ulcerations, Folliculitis and acneiform lesions, Miliaria, Pigmentary alterations, Granulomas

Allergic Contact Dermatitis-Cellular Mechanism u Afferent Limbs (3 days to several weeks) u Binding of allergen to skin component- Langerhans cells (LCs) – IL-1 u Recognition of allergen-modified LCs by specific T cells –IL-2 u Proliferation of specific T cells in draining lymph node u Propagation of specific T-cell progeny u Efferent Limbs (1 -2 days)

Allergic Contact Dermatitis--Morphology u Acute, subacute, or chronic dermatitis u eczematous u Rare process in an unnatural distribution manifestation u erythema multiforme-like u purpuric eruption u lichen planus-like u pigmented reactions u granulomatous reactions

Distinction of ICD and ACD u Morphology u Onset of symptoms u Itching versus sting and burn u Vesicles u Generalized u Patch test

Occupational Dermatoses u Skin Disease: 24% of reported occupational disease u Contact Dermatitis: 95% of occupational skin disease u History and Physical examination u Plant Survey u Patch Test

Patch Test (PT)--History u Father of PT-- Josef Jadassohn (1863 -1936) u 1895 -1960 s-- nonconsensus u 1962 Scandinavian Committee for Standardization of Routine Patch Testing u 1967 International Contact Dermatitis Research Group (ICDRG)

Patch Test--Indication u History and clinical picture of CD u Hand, arm, face, leg eczema u Atopic dermatitis, seborrheic dermatitis, Nummular eczema (sometimes) u Before recommending alterations

Patch Test--Test System u. Original System u. Patches (chambers) utapes uallergens uvehicles u. Ready-to-use System (TRUE test)

Patch Test--Testing Materials u. Standard Series u. Special Screening Series u. Patients’ own working materials or skin care products

Patch Test--Reading u. Exposure u. When Time: 48 hrs to Read

Patch Test--Recording of Results (ICDRG) u ? + Doubtful reaction u+ Weak positive reaction u faint erythema only u erythema, u ++ infiltration, possibly papules Strong positive reaction u erythema, u +++ infiltration, papules, vesicles Extreme reaction u intense erythema, infiltration and coalescing vesicles u IR Irritant reaction u NT Not tested of different types

Patch Test--Recording of Results (NACDG) u 1 = Weak (non-vesicular) reaction; erythema, infiltration, possibly papules (+) u 2 = Strong (edematous or vesicular) reaction (++) u 3 = Extreme (spreading, bullous, ulcerative) reaction (+++) u 4 = Macular erythema only u 5 = Irritant morphology u 6 = Negative reaction (-) u 7 = Not tested u 8 = Not done

Patch Test--Interpretation of Results u Positive Reaction not always mean Allergic or Relevant u ACD versus ICD: no morphological way of distinguishing a weak irritation from a weak allergic reaction u Ring-Shaped Test Reactions (Edge Effect) 水溶液因外圈較濃，故反應較強 含steroid，會使中央inflammation減緩，外圈反應較強烈

Patch Test--False Positive u Concentration, Excess amount u Vehicle is irritant u Impurity or contamination u Current or recent dermatitis at test site u Current dermatitis at distant skin sites u Pressure effects, mechanical irritation u Adhesive tape reactions u Patch itself cause reactions u Artifacts

Patch Test-- False negative u Insufficient penetration of allergens u concentration, vehicle, amount, occlusion, duration of contact, location u Reading Time u Topical Corticosteroids, Irradiation u Systemic corticosteroids or Immunomodulators u Allergen is not in active form u Compound Allergy

Patch Test--Complications u Sensitization u Irritant reaction from nonstandard allergens or products brought by the patient u Flare of previous or existing dermatitis u Depigmentation, Pigmentation u Scars, Keloids u Anaphylactic reactions or shock u Infections

Other Tests u Open u Use Test (ROAT: repeat open application test); (PUT: provocative use test)

Testing Patient-Supplied Products-Reasons u Standard kits of allergens do not contain all possible allergens u Rapid change in new allergens u Little information on composition of most cosmetics, industrial and household products u Compound Allergy

Testing Patient-Supplied Products-Chemical Substance u check labels, confirm identity, exact nature or specific group u unknown substances u litmus paper to check p. H u open test or semi-open tests u patch test 0. 01%, 0. 1% X 1 day

Testing Patient-Supplied Products-Topical Pharmaceutical Products u Patch Test as is: most creams, ointments, gels u Usage Tests u Semi-Open Test: products contain irritant, e. g. iodine alcohol, antiseptics

Testing Patient-Supplied Products-Cosmetics u Patch Test u skin-care creams, lotions; makeup; deodorants u Usage Tests u Semi-Open Test u present of solvents or irritant substances u mascaras, hair dyes, nail varnish, shampoo, liquid soaps, permanent-wave solutions

Testing Patient-Supplied Products-Woods, Plants, Foods u Patch Test as is u most flower, stem, fruit or root of fresh plant; wood dust u Extract with water, alcohol, acetone, etc. then patch test

Testing Patient-Supplied Products-Household and Industrial Products u Never Test u strong detergents, paint stripper, abrasive powders, strong acids or alkali u Individual ingredients must be tested separately in appropriate diluted form u Open or Semi-Open Tests u products with solvents or emulsifiers such as paints, resins, varnishes, glues, waxes, cooling oils u Solids u scrapings, as is u extract with certain solvents

Testing Patient-Supplied Products-Clothing, Shoes, Gloves u Gloves: thin strips, as is u Shoes: pieces from area of dermatitis, as is u Textiles: u small fragments, moistened, as is u soaked in water 10 -15 min (finishes) u soaked in acetone or ethanol 30 -60 min (dye) u extract with boiling water or ethanol

Phototoxic Dermatitis (PICD) u Mechanism: u. Excited oxygen species cell damage u. Monoadducts DNA cross-linking u Clinical manifestation: u. Subclinical inflammation, hyperpigmentation u. Exaggerated sunburn

Phototoxic Dermatitis (PICD) u. Onset: u. Tar: quickly u. Furocoumarins or psoralen: delayed, 2 -3 days

Phototoxic Dermatitis (PICD) u Coal tar derivatives u Drugs: phenothiazines, sulfonamides u Dyes: anthraquinone, eosin, rose bengal etc. u Furocoumarins: u Therapeutic: psoralen u Fragrance materials u Plants: lime, lemon, celery, etc.

Photoallergic Dermatitis (PACD) u Sunscreens: PABA, benzophenone, cinnamate, dibenzoylmethanes u Fragrances: musk ambrette, 6 -methylcoumarin, sandalwood oil u Antibacterial agents: triclosan, chlorhexidine etc u Therapeutic agents: diphenhydramine, psoralen, thiazide, sulfonylurea, chlorpromazine, promethazine

Photopatch Testing u Day 1: u. Apply two sets of antigens u. Determine MED in UVA range u Day 3: u. Remove antigens u. Irradiate one set of antigens with UVA u Day 5: read patch and photopatch tests u Day 5+: second reading

Immediate Contact Reactions u Definition u Symptoms u Immunological (Ig. E-mediated) immediate contact reaction u Nonimmunological immediate contact reaction u Reported Agents: animal products, metals, plant, preservatives and disinfectants, Natural Rubber (Latex), miscellaneous

Skin Tests for Immediate Hypersensitivity u Skin Prick Test u Scratch-Chamber Test u Open Application Test u Rub Test

Skin Tests for Immediate Hypersensitivity-Suppressing Factors u Sedating H 1 antihistamine: 1 -3 days u Nonsedating H 1 antihistamine: u astemizole: 3 -4 weeks u others: 1 -4 days u Prednisolone: over 10 mg