CONTACT DERMATITIS
Martín GraciaFacultad de Medicina Universidad Nacional de Colombia.Dermatología.
DEFINICIÓN
Alteración inflamatoria frecuente Exposición a varios antígenos e irritantes
Mecanismos distintos tipos Eczema de contacto o dermatitis de contacto alérgica
(reacción de hipersensibilidad de tipo IV)
Dermatitis de contacto irritativa (de causa no alérgica)
Fotodermatitis de contacto (reacción de tipo IV)
Urticaria de contacto (reacción de hipersensibilidad de tipo I)
DEFINICIÓN
Presentación clínica Vesículas y bullas localizadas sobre una piel eritematosa
estadios agudos
Placas eritematosas liquenificadas estadios crónicos
Diagnóstico Localización – erupción
Historia – exposición
Pruebas epicutáneas - aplicación alergeno producirá inflamación
DEFINICIÓN
Tratamiento eliminación – agente uso de cremas esteroides antiinflamatorias antihistamínicos
casos graves corticosteroides orales
Eczema de contacto o dermatitis de contacto alérgica
Eritema
Eczema de contacto o dermatitis de contacto alérgica; fotodermatitis de contacto
Eritema, excoriación, descamación, liquenificación y edema
Eczema de contacto o dermatitis de contacto alérgica
Eritema, excoriación, liquenificación y costras
Eczema de contacto o dermatitis de contacto alérgica
Eritema, fisuras y descamación
Eczema de contacto o dermatitis de contacto alérgica
Eritema y costras
fotodermatitis de contacto (reacción de tipo IV)
Eritema, hinchazón y vesículas
Dermatitis de contacto irritativa (de causa no alérgica)
Eritema, edema, ampollas
Dermatitis de contacto irritativa (de causa no alérgica)
Eritema, edema, ampollas, vesiculas, hinchazón
Dermatitis de contacto irritativa (de causa no alérgica)
Descamación, erosiones, escoriaciones, costras
Dermatitis de contacto irritativa (de causa no alérgica)
Eritema, vesiculas, descamación y edema
Epidemiology
the most common occupational disease in the United States
90% skin disorders workplace 6 million chemicals
3000 have been known to cause allergic contact dermatitis (ACD)
New chemical sensitizers are introduced annual cost $250 million
Lost productivity medical care disability payments
Epidemiology
Allergic contact dermatitis (ACD) does occur in children and infants
Allergic versus irritant contact dermatitis
Distinguishing allergic and irritant triggers Clinical and histologic examination
Allergic versus irritant contact dermatitis
Both forms of contact dermatitis involve an inflammatory pathwayThe reactions of ICD are nonimmunologic
Direct epidermal keratinocyte damageconcentration irritant duration contact
ACDAffects genetically susceptible persons
Previously sensitized by allergen
Allergic versus irritant contact dermatitis
FR Physical conditions
Heat Cold repeated frictional exposure Low humidity
Prior damage – skin Dehydration Trauma Compromises – integrity - epidermal barrier (stratum
corneum)
*more vulnerable to irritants
Allergic versus irritant contact dermatitis
Atopic persons
Greater susceptibility ICD
phenomenon caused by ‘‘itch - scratch cycle’’ of AC
increased penetration of irritants no allergens Tendency in atopy to favor pathways of the Th2
rather than the Th1 pathways of ACD
Dermatitis de contacto alérgica
Sensitization (afferent phase)
Most allergic diseases immediate hypersensitivity response involving IgE
ACD prototypic delayed (or cell-mediated) hypersensitivity reaction
Previously sensitized T-helper cells
Dermatitis de contacto alérgica
Haptens Contact allergens Covalently bond with
tissue proteins immunogenic initiate afferent phase
Degree of Th1 sensitization proportional to stability hapten-protein couplings
> chemically reactive haptens lipid-soluble low-molecular-weight molecules
easily penetrate the stratum corneum strongly bind carrier proteins
Dermatitis de contacto alérgica
Haptens Within the epidermis
Pinocytosis by Langerhans cellsDegradation of the allergens
Processed peptides Displayed - Langerhans cell surface context - major histocompatibility complex class II molecules
Dermatitis de contacto alérgica
Langerhans cells
migrate regional draining lymph nodes
processed peptides are presented to naïve Th1 cells
Dermatitis de contacto alérgica
New peptidesSpecific T-cell receptormajor histocompatibility complex II
molecules ”found only on the Th1 cells of susceptible
patients”
*Those who have necessary repertoire receptor variable regions genetically rearranged TR-cell
Dermatitis de contacto alérgica
Successful allergen presentation
Langerhans cells interleukin-1
Th1 cells interleukin -2Clonal proliferation newly sensitized Th1 cells
paracortical region of the lymph nodes
Dermatitis de contacto alérgica
Patient’s initial contact
Number of responding Th1 cells is insufficient to a clinically response
But - Then - memory Th1 cells are released into the circulation
Dermatitis de contacto alérgica
Elicitation (efferent phase)Specific memory Th1 cells – circulatingLangerhans cells Allergen
presentation expanded pool of Th1 cells occurs in:EpidermisDermisRegional draining lymph nodes
*Skin-specific homing receptors on the Th1 cells
Dermatitis de contacto alérgica
Th1 cells release inflammatory cytokines interferon-γ chemotactic
macrophages cytotoxic T cells Natural killer cells
Granulocyte-macrophage colony–stimulating factor augments bone marrow’s production
Lymphocytes Granulocytes Monocytes
Dermatitis de contacto alérgica
Culmination
epidermal spongiosis (intercellular edema)
dermal infiltrate*characteristic of ACD Lymphocytic
Dermatitis de contacto alérgica
Latency periodFrom allergen contact to clinical dermatitis
time for Langerhans cells to present the allergen time for Th1 cells to
proliferate secrete cytokines Travel - site of contact
Between 12 to 48 hours - previously sensitized person
Clinical features
HistoryDetailed
Hidden sources of contact allergens
Occupational exposure - highest risk
food production construction printing metal plating (enchapado
en metal) Machine tool operation
(operarios de maquinas) engine service
(Mechanics) leather work (trabajo del
cuero) health care cosmetology forestry
Clinical features
Temporal relationship - days off and return to work recent exposures
Strong allergens poison ivy Effect - hours – days after - one exposure
long-term exposures > ƒ OACDWeak sensitizers chromate
require repeated exposures - months to years to develop sensitivity
Clinical features
Exposures ≠ workplace
Jewelry Clothing Cosmetics Fragrances Soaps Detergents household cleaning
agents paints resins rubbers (caucho y
gomas) latex adhesives topical medicines
Clinical features
One uniformly present feature of ACD is
PRURITUSwithout which the Dx of ACD is
excluded
Physical examination
Appearance - lesion in ACDcorresponds - stage at which the
patient presents.
Physical examination
Acute stageMarked erythemaEdemaVesicle formationEdema predominates if areas of
loose(sueltas) tissueEyelidsGenitalia
Physical examination
VesiclesMultipleSeveremay coalesce into bullae filled with a clear, transudative fluidRupture during the subacute stage rupture oozing(resumar) and eroded(erosion)
eczematous appearance
Physical examination
vesicular fluiddoes not contain appreciable amounts of
the allergendoes not spread the eruption to other
areas of the body or to othermay be replaced by papules
Crustin(Costra) and scaling(descamación) soon become more prominent than the erythema and edema
Physical examination
chronic stage
Papulovesicular lesions disappearLichenification
*The principles of prevention and treatment of ACD remain similar, regardless of the stage.
Differential diagnosis
the physician’s clinical suspicion of ACD may be quite(bastante) high
It is paramount(importante) consider - potentially more serious etiologies
ICD > ƒ confused
ƒ atopic dermatitis
Differential diagnosis
Atopic dermatitis
onset in infancyACD is uncommon in children younger than 8
years oldDry skin and pruritus prominent - before
lesions appear - ≠ ACD afterwardsTends to be symmetrically distributed on
extensor surfaces - on flexural surfaces
Differential diagnosis
Atopic dermatitis
Differential diagnosis
seborrheic dermatitis
predilection for eyebrows nasal labial folds(pliegues naso-labiales) scalp (cuero cabelludo)
Mild pruritus Greasy(grasosa) or oily(oleosa) coating(capa)
with scaly(descamación) irregularly shaped(forma) erythema
Differential diagnosis
seborrheic dermatitis
Differential diagnosis
endogenous dermatosesMore intensely pruritic eruptionsNummular dermatitis
one or a group of coin – shaped eczematous patches 2 to 10 cm in diameter
Usually torso and extremities but not the head
Dyshidrotic dermatitis appears as multiple vesicles 1 to 2 mm in diameter
palms soles lateral aspects of the fingers and toes
Differential diagnosis
endogenous dermatosesNummular dermatitis
Differential diagnosis
endogenous dermatosesDyshidrotic dermatitis
Differential diagnosis
Photocontact dermatitis Interaction
exogenous chemical UV component of sunlight recently ingested drug
sulfonamide Fluoroquinolone Tetracycline Oral contraceptive nonsteroidal anti-inflammatory drug topically applied substance - cold tar extract
(extracto de alquitran frio)
Differential diagnosis
Photocontact dermatitisClinically
sun-exposed areas face arms upper chest
is noticeably spared skin under the chin - behind the
ears - upper eyelids
Differential diagnosis
phototoxic reactions ↔ ICD subset
photoallergic reactions ↔ACD subset
Differential diagnosis
phototoxic reaction
Maculartender erythema
can resemble(parecer) severe sunburn(quemaduras)
Differential diagnosis
photoallergic reactiondelayed hypersensitivity reaction -
induced by UV light which chemically alters the sensitizing allergen in the skin.
PruriticPapulovesicularEczematous
*similar to ACD
Differential diagnosis
two types of contact urticaria subsets of contact dermatitis
Differential diagnosis
nonallergic formurticaria remains localized site of
contact - caused -direct cell mediator release from:
fragrances food preservatives insect stings hairs topical medicines
Differential diagnosis
Allergic contact urticaria IgE-mediated mast cell stimulation requires prior exposure to sensitizing allergens foods metals animal saliva latex industrial products topical medicines
Differential diagnosis
Both forms of contact urticaria resemble noncontact urticaria
classic wheal and flare response appears within 30 minutes of exposure
allergic contact urticaria may become generalized
angioedema or anaphylaxis
Urticaria or angioedema - contact or noncontact - can be –mistaken(confundida) for ACD
*when the eyelids are involved
Differential diagnosis
Both forms of contact urticaria resemble noncontact urticaria
classic wheal and flare response appears within 30 minutes of exposure
allergic contact urticaria may become generalized
angioedema or anaphylaxis
Urticaria or angioedema - contact or noncontact - can be –mistaken(confundida) for ACD
*when the eyelids are involved
Differential diagnosis
Skin infections strongly considered - immunocompromised patientsCellulitis
erythema and edemaDx dif
warmth tenderness Trauma common precipitant fever and leukocytosis
Differential diagnosis
Dermatophytic or tineaDryscaling erythemaannular ring and central clearing
Diagnosis scraping scales glass slide adding potassium hydroxide visualizing branching hyphae
Differential diagnosis
infections present vesicular lesions
herpes simplex virus tendermay umbilicatepredilection for perioral and genital regions
Differential diagnosis
varicella zoster virus
primary varicella
2- to 3-day prodrome of flu like symptoms
erythematous maculopapulesdiffuse, pruritic vesicles
Differential diagnosis
varicella reactivated
few constitutional symptomslocalized pain and paresthesias 2 to
3 days before the eruptiongrouped vesicles in a dermatomal
distribution
Differential diagnosis
Impetigo
all age groups, but is usually seen in young children Streptococcus pyogenes or Staphylococcus aureus involves the face has regional lymphadenopathy self-limited to 2 to 3 weeks vesicles may progress to pustules easily rupture
honey - colored crust
Differential diagnosis
Impetigo
Differential diagnosis
psoriasis thick(espeso) silver - scaled plaques over bright erythema extensor surfaces
mycosis fungoides (Primary cutaneous T-cell lymphoma) asymmetric finely scaled(descamadas) plaques on the trunk
and groin(ingle)
Differential diagnosis
psoriasis thick(espeso) silver - scaled plaques over bright erythema extensor surfaces
mycosis fungoides (Primary cutaneous T-cell lymphoma) asymmetric finely scaled(descamadas) plaques on the trunk
and groin(ingle)
Differential diagnosis
*biopsy low utility in ACD
histologic finding of spongiosis is not specific among eczematous dermatoses
Anatomic approach
Exposure to the suspect allergen - congruent - distribution of the eruption
more exposed areas the hands face
> ƒ presenting ACD
Anatomic approach
Head and neck Scalp have greater resistance than face, ears, and
neck Hair dyes(tintes) Shampoos
often spare the scalp but involve its nearby landmarks
eyelids and cheeks(mejillas) facial cosmetics products applied to the hands nail polish(esmalte)
Anatomic approach
Head and neck common triggers
Metals from jewelry piercings - face and ears
Topical antibiotics EyesEars
Anatomic approach
Neck
cosmetics and fragrancesmetalsexotic woods from necklaces (collares)musical instruments
Anatomic approach
Extremities50% involve the hands
supposed innocuous items foodsmoisturizersmusical instruments,protective gloves
> ƒ fingertips (pulpejos)
Anatomic approach
Extremitiesƒ dorsal side of the hands
the skin is thinnerdensity of Langerhans cells is greater than on
the palmar sideBracelets, watches, and rings
ACD metal exposure ICD soap and detergent accumulation under
Anatomic approach
Extremitiesphotosensitive process
hand dermatitis - contiguous with forearms - associated with a facial dermatitis
dorsal aspect - feet chrome - tanned leather (cuero) glues (pegamentos) rubber (caucho)
components of shoes
Anatomic approach
ExtremitiesStasis dermatitis - lower legs - chronic
varicose inflammation
Significantly increases the risk of ACD from topically applied products
Metals – keys - coins -match boxes(encendedores) - pants pockets upper legs
Anatomic approach
Torso and groin(ingle) Fragrances - deodorants - axillary vault formaldehyde, detergents, and dyes from
clothes torso - axillary folds - sparing vault Rubber chemicals - elastic of under garments
(prendas femeninas) - bra line – waistline (cintura)
periumbilical region - metallic fasteners(cierrres) – belts(cinturones) – pants
Anatomic approach
Torso and groin(ingle)Incontinent bed – bound(obligados)
patients - urine - diaper (pañal)ƒ Contraceptive devices latex-
sensitiveMedicines, douches, spermicides
genital area - vulva and adjacent thighs(muslos) ≠ vaginal mucosa
Anatomic approach
Oral mucosa Langerhans cells are sparse(escasas) at mucosal sites contact stomatitis
contact gingivitis cheilitis
Dental metals - amalgams Nickel Palladium Mercury Gold
Anatomic approach
Oral mucosasaliva - buffering and diluting effect on the
allergen
rapid dispersal and absorption of the allergen extensive vascularity in the mouth
low incidence of contact stomatitis
Anatomic approach
Systemic involvement Systemic ACD - form of autoeczematization - known as an ‘‘id
reaction.’’ Secondary dermatitis - patients sensitized topically - subsequently
re-exposed systemically re-exposure
orally intravenously intramuscularly rectally vaginally inhalation after dental surgical devices implanted
Anatomic approach
Systemic involvement ‘‘id reaction.’’
Generalized eruption - result - hematogenous dissemination - antigen-specific Th1 cells
Common contact allergens
Allergens
Poison ivyspecie: Toxicodendron genus plant family: Anacardiaceae the most ubiquitous of four especies family includes
poison sumacpoison oak
Allergens
Poison ivy United States - responsible -more cases – ACD Strong sensitizing allergen urushiol - catechol
derivative – sap (savia)sap - difficult to wash offwashing - ideally within 10 minutes of exposure
dermatitis linear erythema and vesiclesvesicular fluid - no allergenic
Allergens
Poison ivy chronicity and spread(propagación) of symptoms
continued unintentional exposure urushiol may persist on clothing, tools, sports equipment, -
fur(piel) of pets(animals) Cross-reactions - catechol derivatives- found in other
members - Anacardiaceae family Mangoes Cashews Ginkgoes Brazilian peppers(pimienta)
Allergens
Metals
Nickel most common metal allergen prevalence women higher - early sensitization ear
piercings Other
Chromium Cobalt Gold organic forms of mercury
Allergens
Metals
Sensitivity to aluminum is quite uncommon substitution with aluminum items - workplace -
reduce the incidence metal alloys(aleación) - medical devices – implants
stainless steel contains - nickel and chromium may present - persistent - localized or generalized eczema -
loosening - implant Patch testing - metals - low specificity - moderate
sensitivity work-up - metal implant
Allergens
MedicationsTopical antibiotics
> ƒ neomycin and bacitracin*mupirocin may to be a safe alternative
Topical anestheticsester class
benzocaine and tetracaine ƒ lidocaine, dibucaine, and mepivacaine, are rare
sensitizers
Allergens
Medications Topical corticosteroids
structure may be altered to induce allergenicitymetabolism in the skindegradative reactions within the pharmaceutical
preparation topical antihistamines
known to act as sensitizers may predispose to an id reaction after systemic
administration
Allergens
MedicationsEthylenediamine
Common allergenic preservative found in
aminophyllinesome antihistaminessometopical medicines
Allergens
Medicationsthimerosal
Preservative with the highest prevalence of positive patch tests
found invaccinesnumerous topical medicines for the eyes, ears,
and nose
Allergens
Latex and rubber(caucho) chemicals Latex fluid - Brazilian rubber tree - Hevea brasiliensis Vulcanization
Chemical accelerators Antioxidants
ThiuramsCarbamatesMercaptobenzothiazole
*primary sensitizers
Allergens
Latex and rubber(caucho) chemicals
Immediate hypersensitivity reactions mediated - specific IgE against - latex protein
Responses Urticaria Rhinitis Conjunctivitis Asthma Anaphylaxis
within minutes
Allergens
Latex and rubber(caucho) chemicals
*airborne(aera) exposure proteins-Latex
latex gloves – to cause immediate-type reactionsdelayed-type reactions – ACD> ƒ ICD.
Allergens
FormaldehydeFormaldehyde itselfformaldehyde–releasers = quaternium-
15, are the most common ƒ preservative ≠ thimerosal ACD
cosmeticsmoisturizers fabrics (telas)
Allergens
FragrancesCosmeticsFabrics topical medicines flavorings (aromatizantes) of foodsdrinksspices (especias)oral hygiene productsperfumes and colognes
Allergens
FragrancesBalsam of Peru >ƒ ACD - nonallergic
contact urticaria*In addition to mentioned products
Sunscreens Shampoos
beneficial actions - side effects stimulate capillary beds increase local
circulation
Patch testing
gold standard – Dx ACD first use
1895 Josef Jadassohn suspected - rash - result - mercury sensitivity
refined- simple reproducing – ACD
allergen - same or cross-reactingsmall area – back
Patch testing
Standardized allergens- delivery vehiclesACD eruption appears - 2 to 3 days of
sufficient allergen contactpatch testing - performed - at least a 3-day
periodnumber of allergens - depends
physician’s clinical suspicion likely culprits
Patch testing
Screening panels - 20 to 30 - most prevalent allergens>ƒ TRUE Test (Mekos Laboratories A/S,
Hillerød, Denmark)23 allergensone negative control
gel delivery system
Identifies about 70% - clinically relevant
allergens
Patch testing
*Another option assortments(diversidad) of allergens
Filter paper in 8-mm aluminum disks ‘‘Finn Chambers’’ (Epitest Ltd Oy, Tuusula, Finland)allergen dispersion -Along - 5-mm ribbon of
petrolatum -
Patch testing
Techniques
Applied Allergens togetherhairless regionupper backbetween - spine and scapulazone washed
Patch testing
TechniquesAn adhesive keeps the allergens
securedEdges(bordes) - marked with a pen.Patients - return - physician’s office - 48
to 72 hoursRemoved patch - Waiting 20 to 30 minutes
reactions are gradedThird visit 24 to 96 hours later
Patch testing
Techniqueslonger allergic response
Elderly patientsallergens - late phase reactions
cobalt neomycin topical corticosteroids
Patch testing
PrecautionsNot be performed in - acute or
widespread(extendida) contact dermatitisPositive patch test reaction may progress to
autoeczematizationPruritus within minutes of application
suspicions - contact urticaria - possibility anaphylaxis if patch is not removed
Patch testing
to consider bacitracin and gold are not TRUE Test panels
prevalent allergens Poison ivy also is not included urushiol’s
sensitizing may cause severe reactions May need to be delayed - potent topical
steroids -near test site Systemic steroids
doses of 20 mg or less of prednisone daily - not inhibit positive reactions
Patch testing
to consider bacitracin and gold are not TRUE Test panels
prevalent allergens Poison ivy also is not included urushiol’s
sensitizing may cause severe reactions May need to be delayed - potent topical
steroids -near test site Systemic steroids
doses of 20 mg or less of prednisone daily - not inhibit positive reactions
MANAGEMENT
treating the active case Prevention
treatment Topical corticosteroids Soap substitutes Emollients
Second line treatments topical PUVA azathioprine cyclosporin
steroid resistant chronic dermatitis
MANAGEMENT
MANAGEMENT
MANAGEMENT
MANAGEMENT
PREVENTION workplace eliminating harmful exposures
substitution of chemicals less irritating or allergenic
introduction of engineering controls Organization of work all employees are exposed
to the same degree Uses of personal protection
Gloves
Selection of less susceptible individuals
MANAGEMENT
correct selection of glovesCotton gloves
allow the skin to ‘‘breathe’’could be used for dry workWet work thin cotton gloves
absorb sweat inside rubber or vinyl gloves
MANAGEMENT
Barrier creamsquestionable value in protecting against
contact with irritantsAfter-work creams
Controlled clinical trials have shown benefit reducing the incidence and prevalence
approved industrial skin cleansers
MANAGEMENT
PRE-EMPLOYMENT SCREENING
predisposing factorsAtopic dermatitishand eczemaxerosis
MANAGEMENT
WORK RELATED EDUCATIONAL PROGRAMMESHalf OCDs appear first two years of
employment recognition of early signs and symptoms proper use of protective clothingafter-work creamspersonal and environmental hygiene