Mark H. Lowitt, MD Clinical Associate Professor of Dermatology
-
Upload
prezi22 -
Category
Health & Medicine
-
view
386 -
download
3
Transcript of Mark H. Lowitt, MD Clinical Associate Professor of Dermatology
Mark H. Lowitt, MD
Clinical Associate Professor of DermatologyUniversity of Maryland School of Medicine
Private Practice, Greater Baltimore Medical Center
Contact Dermatitis
CasesClinical Features of Allergic Contact DermatitisMechanisms of Allergic Contact DermatitisPatch Testing
Case 151 y/o FPhlebotomistItchy and painful fingers
and hands, worsening over years
Not seasonal
What’s the diagnosis?What’s the cause?
Case 2Same photo 73 y/o F
Severe eyelid pain and itch worsening over weeks
What’s the diagnosis?What’s the cause?
Case 340 y/o M
Auto mechanic for 20 years
Similar eruption on feet
What’s the diagnosis?What’s the cause?
ErythemaEdemaVesiculationScalingLichenificationWell defined edges
and Straight linesPruritusHistory: The more you treat, the worse it gets
What’s new in contact dermatitis?What makes a good contact allergen?
Low molecular weightLipophilicAble to form covalent bonds with nucleophilic residues on
amino acid side chainsSensitizing potential may be related to chemical reactivity
toward a few specific amino acids involve in sensitization Esp. cysteine residues
North American Tray
Metals: Nickel, Gold, Cobalt, CopperFragrances: Fragrance mix, Balsam of Peru,
Isoeugenol, LyralPreservatives: Quaternium-15, Paraben mix,
Formaldehyde, Kathon CG, Propylene glycol, Thimerosol
Medications: Neomycin, Bacitracin,Tixocortol-21-pivalate, Budesonide
Dyes: P-phenylenediamine, Disperse blueRubber products: Mercaptobenzathiazole, Carba mix,
thiuram mix, mixed dialkyl thioureaOther: Benzocaine, Colophony, ethyl acrylate
Hand DermatitisAllergic Contact DermatitisIrritant Contact DermatitisDyshidrotic EczemaPalmar psoriasisTinea ManumMycosis fungoides
Hand DermatitisPatch test positive for Quaternium-15
Common preservative
Chronic Hand DermatitisMajor Occupational Health Problem40% of all Occupational Health Claims are from skin90% of these are Dermatitis
65% are Irritant Contact 35% are Allergic Contact
THEREFORE, 12% OF ALL WORKMAN’S COMP CLAIMS ARE DUE TO ALLERGIC CONTACT DERMATITIS
Allergic Contact Dermatitis of the Hands22,035 patients patch tested between 1994 and 20046953 had hand involvement959 with a solitary dx of ACD
Quaternium-15 17%Formaldehyde 13%Nickel 12%Fragrance Mix11%Thiuram Mix 10%
Eyelid DermatitisDifferential Diagnosis
Contact dermatitisAtopic dermatitisDermatomyositis
Atopic dermatitis
Dermatomyositis (heliotrope rash)
Patch testing:Positive for Gold sodiumthiosulfate
May be 10% of positive patch testsMore common in women8% of gold + pts have eyelid dermatitisClinical picture can be confusing due to presence of nickel
in gold alloys
Eyelid DermatitisMost common causes of eyelid allergic contact dermatitis:
Gold 22%Fragrance mix 19%Balsam of Peru 17%Nickel 16%Neomycin 9%
Treatment with topical cortisones initially help, but then the condition worsens
Tinea manum (dermatophyte infection)
Patch test positive for BudesonideCross reacts with triamcinolone, fluocinonide, fluocinolone,
desonide, budesonideCorticosteroids were the American Contact Dermatitis
Society 2005 “Allergen of the Year”
Corticosteroid allergyClass A Hydrocortisone and tixocortol type
Cortisone, hydrocortisone, methylprednisolone, prednisoloneClass B Triamcinolone acetate type
Triamcinolone, halcinonide, flucinonide, fluocinolone, desonde, budesonide, amcinonide
Class C Bethamethasone typeBetamethasone, dexamethasone, flucortolone
Class D Hydrocortisone-17-butyrate and clobetasol 17-butyrate
Patient education – CARD Database
Allergic Contact Dermatitis: ReviewHave a high index of suspicion for ACD
Angulated lesions with straight edges and unusual shapeA refractory dermatitis
However, keep your mind open: not all dermatitis is allergic
Allergic Contact Dermatitis: ReviewPatch testing can help to identify the allergenHand dermatitis most often caused by quaternium-15Eyelid dermatitis most often caused by goldIn pts not getting better, consider contact dermatitis to
topical steroids
www.contactderm.org American Contact Dermatitis Society (ACDS)
www.dormer.com Dormer Labs (Canada)
patch test materials
www.allergEAZE.com patch test materials