A n a M G i m é n e z A r n a u

D e p a r t m e n t o f D e r m a t o l o g y a n d V e n e r e o l o g y .

H o s p i t a l d e l M a r . U n i v e r s i t a t A u t ò n o m a . B a r c e l o n a . S p a i n

Patch Testing T-cell mediated diseases: Principles and Practice

a.g.a Erlanguen 2013

• Contact Dermatitis is an inflammatory skin reaction to direct contact with noxious agents in the environment

• This entity was recognized as disease in ancient times. Early recorded reports include Pliny the Younger who, in the first century A.D., noticed individuals with severe itching when cutting pine trees

• The history of contact dermatitis in the twentieth century is indistinguishable from the history of patch testing, which is considered the main tool for discover the etiology being a chemical or a protein involved

Contact Dermatitis How important is in your daily practice

Contact Dermatitis. Fifth Edition .

Eds Jeanne Duus Johansen, Peter J Frosch , Jean-Pierre Lepoittevin.

Springer-Verlag Berlin Heidelberg 2011. a.g.a Erlanguen 2013

• Dermatitis means inflammation of the skin

• Eczema, from Greek, term ekzein, “to boil over”,

relates to the spongiotic vesiculation of the

epidermis characteristic of some stages

Dermatitis and Eczema Are these synonyms or do they mean distinct entities?

There are not a disease in itself,

but comprises a group of skin disorders exhibiting a

common pattern of histological and clinical findings which

vary depending on the stage of the disease

Contact Dermatitis. Fifth Edition .

Eds Jeanne Duus Johansen, Peter J Frosch , Jean-Pierre Lepoittevin.

Springer-Verlag Berlin Heidelberg 2011. a.g.a Erlanguen 2013

Eczema

Greek, term ekzein, “to boil over” - vesicle

Hospital del Mar.

• Itchy cutaneous

inflammation

• erythema

• vesiculation,

• exudation,

• crust and

• lichenification.

Acute

Chronic a.g.a Erlanguen 2013

Eczema Greek, term ekzein, - spongiosis and exocytosis

• acanthosis

• espongiosis

• exocytosis

• dermal

inflammatory

infiltrate

a.g.a Erlanguen 2013

Hospital del Mar.

Eczema vesiculation / espongiosis and exocytosis - types

• contact

• irritant

• allergic

• photo allergy

• photo toxicity

• atopic

• nummular

• drug induced

• dishidrotic

• microbial

a.g.a Erlanguen 2013

• There is difficult to establish the prevalence or incidence of contact

dermatitis in general population from clinical epidemiology

• Prevalence of hand eczema, contact sensitivity and contact dermatitis in

general population from cross-sectional studies,

• lifetime prevalence of hand eczema of 9%

• 1-year period prevalence of 7.3%

• point prevalence of 3.2%

• The point prevalence of contact allergy was 15%

• Most common contact allergens nickel (8.6%) & fragrance mix (1.8%)

Contact Dermatitis Epidemiology

Mortz cG, Lauritsen JM, Bindslev-Jensen C, Andersen KE. Contact allergy and allergic contact dermatitis in

adolescents: prevalence measures and associations. The Odense adolescents Cohort Study on Atopic

Diseases and Dermatitis (TOACS). Acta Derm Venereol 2002;82: 352-358 a.g.a Erlanguen 2013

• eczema • erosions,

• ulcerations,

• urticaria,

• erythema multiforme,

• purpura,

• lichenoid eruptions,

• exanthemas,

• erythroderma,

• allergic contact granuloma,

Contact Allergens Clinical patterns

• lymphocytoma,

• sarcoidal reactions,

• toxic epidermal necrolysis,

• pigmented contact

dermatitis,

• contact leukoderma,

• nodular lesions

• photosensitive reactions

• generalized symptoms

• contact urticaria may

become anaphylaxis.

Assess type of eczema and suspected trigger factor

Assess active principle and excipient

Repeat Open Application Test, ROAT

Immediate Delayed

Open patch test

Occluded patch test

Scratch test

Prick test

Intradermal test

Photo patch test

Photo Prick test

Occluded patch test

Semioccluded patch test

Scratch test

Intradermal test

Subcutaneous test

Diagnosis Allergic Contact Dermatitis

• First introduced by Jadassohn in 1896

• Is the gold standard method for the detection of the causative contact allergens

• The positive patch test reproduces an experimental contact dermatitis on a limited area of the skin

• A good patch test indicates contact sensitization of past or present relevance

Diagnosis Allergic Contact Dermatitis - Patch Test

• Negative (-)

• Doubtfull (+/-):

• Mild erythema

• Positive mild (+):

• erythema, infiltration, papule

• Positive (++):

• erythema, infiltration, papule, vesicles

• High Positive reaction (+++):

• erythema, infiltration, papule, vesicles, bullae

• No desirable : Necrosis

Allergic Contact Dermatitis Diagnosis – reading 2, 4 and 7 days

Hospital del Mar.

Active or widespread dermatitis

Excessive sun exposure

Systemic steroids (> 20 mg, > 1 month)

Topical steroids at the site of patch test

Systemic immunosuppressant

Pregnancy

Allergic Contact Dermatitis Patch test contraindications

Dermographism

Hospital del Mar.

Likely to develop in patients with a longer duration of the primary dermatitis

Causes, strongly positive reaction or skin hyper-reactivity

Later sequential testing with each substance alone is recommended

Allergic Contact Dermatitis Patch Test Complications

Ungry Back

• Irritant reactions,

• Test only normal appearing skin

• Do not prepare skin by cleansing with soap or solvents

• Avoid testing with non-standardized materials

• Don’t patch test if widespread dermatitis or status eczematicus

• Flare of ectopic dermatitis

• Koebner phenomenon

• Persistent reaction , > 1 month e.g. gold

• Alteration of pigmentation, avoid hydroquinone

• Anaphylactoid reactions, e.g. ammonium persulfate

• Edge efect, habitually dissapear

• Pustular reaction

• Pressure effect

• Bacterial and viral infection

• Necrosis, scars and keloids

• Pseudolymphoma (gold and metals)

Allergic Contact Dermatitis Patch test complications

• Positive patch test 7 or more days later with no early positivity

• Interactions of residues of allergen with newly sensitized tissues

• Detection:

• Positive patch test 14 days after application (flare-up)

• 2 – 4 days after later repetition of patch test

• Most common cause:

• Use of too high concentration of the test substance

• Active sensitization is rare with standard allergens

• Causative allergens: e.g. Paraphenylenediamine (PPD)

Active sensitization

Allergic Contact Dermatitis Patch Test Complications

1. Patient with suspected allergic contact dermatitis

2. To confirm the offending antigen even if obvious

3. Atopic dermatitis exacerbated by ACD

4. Preexisting dermatitis superimposed by ACD (e.g.: stasis dermatitis)

5. Occupational contact dermatitis

6. Chronic hand dermatitis

7. Photodermatitis (sunscreens, topical NSAIDs)

8. Contact Urticaria (latex, metals, epoxy resins)

9. Protein contact dermatitis (amylase, rat hair, crab meat)

10. Adverse drug eruption (AGEP, maculopapular, FDE, erythroderma)

11. To identify potential health hazards of newly introduced potential allergens for the medical community and industrial hygienist

Allergic Contact Dermatitis Patch Test indications

• Patch test all the patients with hand eczema

longest than three months or at least two

acute forms per year, with the objective to

identify the role of contact allergens in its

pathogenesis

• Clinical relevance of contact allergens is

independent from the clinical pattern and its

severity

Allergic Contact Dermatitis Semiocclusive Patch test

Dooms-Goossens A (1995) Patch testing without a kit: In Guyin JD (ed) Practical Contact Dermatitis . McGraw-Hill , New York , pp 63-74

. Direct application on the skin, with a cotton Q-tip, of an amount

(1 to 2 µl) of a liquid on a skin surface of about 1 cm2

. After complete evaporation of the liquid (the excess can be

removed with a paper filter or another Q-tip)

. The completely dry test site is then covered with acrylic tape

. Also diluted products (e.g. 1-2 % aqueous) tested this way

. Reading of the skin test is performed as regular patch testing

• High prevalence

• Model pathogenesis needs further inside

• Broad spectrum of trigger factors

• Improve diagnostic tools

• Quality of life impairment

• Occupational relevance

• Multidisciplinary approach

• Work in Networks

• Human health hazards

• New therapy

• Preventive measures

• Regulatory affairs

Allergic Contact Dermatitis How important is in our daily life ?