Allergic contact dermatitis Flashcards
(116 cards)
1
Q
What are the most common causes of allergic dermatitis on the lips?
A
- gallates
- dyes
- flavorings
- sunscreens
- propolis
2
Q
What is the common cause of allergic contact derm on the wrist?
A
Chromates (in leather)
3
Q
What areas are spared in clothing dermatitis?
A
Spares folds (axillary vault) and is accentuated where clothes fit tightly.
4
Q
What is the main cause of cosmetics dermatitis?
A
fragrances
Preservatives are second most common.
5
Q
What is the most common cause of airborne ACD?
A
Compositae
6
Q
What type of skin reactions are most commonly caused by tape?
A
Irritant contact dermatitis
7
Q
What causes more allergy, pure metals or metal salts?
A
metal salts
8
Q
What test do you do to see if something has nickel?
A
Dimethylglyoxime
It turns pink in the presence of nickel.
9
Q
What are the sources of Chromates?
A
- dyes (green felt fabric on pool table)
- yellow green pigment (tattoos/cosmetics)
- leather
- cement
- matches
- crude oils
10
Q
What is the indicator test for Chromates?
A
Diphenylcarbazide spot test
11
Q
What is the molecule used for the cobalt release spot test?
A
disodium-1-nitroso-2-napthol-3,6-disulfonate
(nitroso-R salt)
12
Q
What irritant dermatitis do you get with cobalt?
A
Irritant reaction w/ purpuric pores.
This type of dermatitis occurs when cobalt directly irritates the skin, leading to symptoms such as redness, itching, swelling, and sometimes blistering.
13
Q
What does cobalt commonly cross react with?
A
nickel and chromate
14
Q
What type of reaction can mercury cause?
A
Oral lichenoid reaction
15
Q
What substances does latex cross-react with?
A
bananas, avocado, chestnut, kiwi, passion fruit
16
Q
What is the most common glove allergy?
A
Thiuram
(tetramethylthiuram disulfide)
17
Q
What substance does thiuram cross react with?
A
Disulfiram
18
Q
What is the main cause of allergic shoe dermatitis?
A
Mercaptobenzothiazole
(MBT)
19
Q
What is the indicator test for formaldehyde?
A
Lutidine
(acetylacetate)
20
Q
What type of textile has the least amount of formaldehyde?
A
polyester
21
Q
What is the primary preservative sensitizer in the USA?
A
Quanternium-15
It releases formaldehyde over time.
22
Q
What products contain Kathon CG
(methylchloroisothiazolinone/methylisothiazolinone, MCI/MI)
A
wet wipes
23
Q
Can you give a child a vaccine with a positive patch test to thimerosal?
A
Yes
This positive result is almost never relevant.
24
Q
What is the difference between fragrance-free and unscented?
A
- Fragrance free doesn’t have any fragrance .
- Unscented may have masking fragrances.
25
What transdermal patch causes the most allergic contact dermatitis?
Clonidine
26
Which corticosteriod group is least likely to cause allergy?
Class C, screening agent is Betamethasone
27
What allergens are in the PPPASTE family?
PPD, PABA, Para-aminosaliciylic acid, azo dyes, sulfonamides, thiazides, and ethyl anesthetics
28
Which is more common, irritant or allergic contact dermatitis?
Irritant is more common, 80% of cases vs 20% being allergic contact
29
How long does sensitization take for allergic contact dermatitis?
Can vary from a few exposures or after years of exposure
30
How often is exposure required to maintain an allergic reaction in allergic contact dermatitis (ACD)?
Exposure is needed approximately once every 3 weeks to sustain the allergic reaction.
31
What is the **difference** between cross reaction and co-reaction for allergic contact dermatitis?
* **Cross reaction**: Sensitization to one compound leads to sensitivity to others with a similar chemical structure (e.g., poison ivy and mango peel; neomycin and gentamycin).
* **Co-reaction**: Simultaneous sensitization to two chemicals due to joint exposure, though one wouldn't typically cause sensitivity to the other (e.g., nickel and cobalt; neomycin and bacitracin).
32
What is the #1 flower associated with fingertip allergic contact derm in florists?
Tulips
33
What type of pattern might you see for allergic contact derm w/ hair products?
Since the scalp is thick and resistant to allergy it will often presetn on the ears and hairline/face
34
What nail products may contribute to periocular/eyelid dermatitis?
tosylamide\>acrylates, formaldehyde, resin, glutaraldehyde, benzalkonium chloride
35
#1 cause of allergic contact dermatitis on the face/neck?
Fragrances, preservatives are 2nd
36
Most common cause of perianal dermatitis
Lidocaine (hemorrhoid gel) and preservatives (MCI/MI, in wipes).
37
Most common causes of oral stomatitis (allergic contact)
dental fillings (mercury/gold/amalgam) which give you a lichenoid reaction, eposxy resins and flavorings like mind and cinnamon.
38
Most common occupational exposures for allergic contact demratitis?
Rubber \> nickel \> epoxy and other resins \>aromatic amines
39
What type of dermatitis is caused from most tape reactions?
irritant rather than allergic.
40
In patch testing which compounds can cause a delayed postive patch test (arises after 7 days)?
gold, neomycin, dodecyl gallate, palladium, p-phenyedediamine, and corticosteroids.
41
Which metal can cause a persisitant psoitive reaction at the site of patch testing?
Gold
42
What are some key differences between irritant contact dermatitis vs allergic contact dermatitis on histology?
Allergic has more spongiosis, dermal inflammation and eos and also lacks the necrotic keratinocytes.
43
Which foods have nickel in them that people with nickel allergy should be aware of?
cocoa, licorice, margarine, peanuts, borwn lentils, walnuts, almonst, hazelnuts, beans.
44
What is the indicator compound for nickel and what color does it turn?
Dimethyglyoxime, turns pink.
45
What is the indicator compound for chromates?
diphenylcarbazide spot test
46
What things have chromates?
dyes (green felt fabric on pool table), yellow/green pigment (tattoos/cosmetics), cement, matches, and crude oils (engine aircraft workers and photographers.
47
What do the chromates cross react with?
nickel and cobalt
48
What is the spot test for cobalt?
disodium-1-nitroso-2naphthol-3,6-disulfonate
49
What things have cobalt in them?
metal products, cosmetics, dyes (blue-green dyes, paint, tattoos), glass/pottery, cement, vit B12 inejctions (can cause intractable hand dermatitis), and artificial joints.
50
What is the Poral Reaction associated with cobalt?
This is irritant reaction w/ purpuric sores associated with cobalt exposure.
51
What does cobalt cross react with?
Nickel and chromate
52
What products are mercury in that cause allergic contact dermatitis?
amalgams, insecticides, industry glues and starch pastes, felt hat workers, etching/artwork and furs
53
What is the most common reaction to latex?
Immunologic contact urticaria (type I hypersensitivity) rather than type IV delayed-type hypersensitivity reaction.
54
What things does latex cross-react with?
BACK Passion Bananas Avocados Chestnut Kiwi Passion fruit
55
What is the most common glove allergen?
Thiuram
56
What is the most common allergen in healthcare workers?
Thiuram
57
What does Thiuram cross react with?
disulfiram
58
What allergen is released from bleached elastic?
Carba mix/carbamates
59
What are the main sensitizers associated with rubber?
So it is the accelerants that get you not the rubber: thiurams and benzothiazole derivatives and antioxidants.
60
What is the #1 cause of shoe allergic contact derm?
Mercaptobenzothiazole (MBT)
61
What is the sensitizer in neoprene?
Dialkyl thioureas
62
What products does the allergen P-phenalenediamine (PPD) come from?
Hair dye, black henna, black rubber, photograph development, photocopies, printer ink, other darkly colored cosmetics
63
What things is the allergen Rosin found in?
de-epilation waxes, adhesives, painting, chewing gum, violin and other musical instruments
64
What products is the allergen P-tert-butylphenol formaldehyde resin (PTBP) found in?
Is used for glueing together leather products (watchbands, leather handbags, shoes
65
What specific clinical finding can PTBP cause?
hypopigmentation
66
What products are the allergen Epoxy resin (bisphenol A) found in?
PVC and plastic materials, electrical insulation, pain, glues
67
In what form do the epoxy resin's cause allergic contact derm?
Only in their liquid form, when they have cured and turned into a fully polymerized product they are non-sensitizing.
68
What allergen is in Krazy Glue that you would find for glueig artificial nails?
Ethyl cyanoacrylate
69
What allergen is in GluStitch, sutureles skin closures?
Butyl cyanoacrylate
70
What allergen is in Dermabond, sutureles skin closures?
Octyl cyanoacrylate
71
What type of products are methacrylates in?
very hard rigid plastic. artifical nail plates, hard contact lenses, adhesive bone cement for artifical joints, dental prostheses, dental sealant.
72
What allergen chemical can pass through rubber and polyvinyl gloves?
Methacrylate
73
What clinical finding that is unique can methacrylate cause?
paresthesias
74
What is the indicator test for formaldehyde?
Lutidine (acetylacetate)
75
What allergen is common in wrinkle-free clothing?
Formaldehyde
76
What products is the allergen quanternium-15 (Dowicil 200) found in?
soaps, shampoos, moisturizers.
77
What allergens are found in wet wipes?
Kathon CG (methychloroisothiazolinone/methylisothiazolin one) (MCI/MI)
78
What things do parabens cross react with?
PPPASTE family Para-aminosalicyclic acid PABA PPD Azo dyes Sulfonamides Thiazides Ester anesthetics
79
What products are the allergen propylene glycol in?
ECG and lubricant jelly, antifreeze, brake fluid, food dyes/ flavorings
80
What allergen is derived from coconut oil?
cocoamidopropyl betaine
81
What produces is cocoamidopropyl betaine found in?
shampoo, soaps
82
What products is lanolin in?
aquaphor, wax-wool alcohol, eucerin
83
What allergen is derived from bees and is notable for causing allergic contact of the lips?
Propolis
84
What chemicals will pick of 90% of fragrance allergies?
balsam of peru and fragrance mix
85
What tree does balsam of peru come from?
Myroxylon Pereirea
86
What 8 fragrances are in the Fragrance mix that you test on patch testing?
Cinnamic alcohol, cinnamic aldehyde, amyl cinnamic alcohol, eugenol, isoeugenol, geraniol, hydroxycitronellal, oak moss absolute
87
What is the rare sensitizer found in home hair perms
ammonium thioglycolate (more offten causes irritant)
88
What is the sensitizer found in acid/professional/salon perms?
glyeryl monothiogycolate
89
What is in nail lacquer/polish which causes eyelid, neck and finger-periungal dermitits?
Tosylamide (toluene-sulfonamide)
90
What is the screening agent for Class A corticosteroids?
Tixocortol pivalate
91
What are the most frequent allergenic Class A corticosteroids?
hydrocortisone, prednisone, prednisolone, and methylprednisolone
92
What is the screening agent for Class B steroids?
Budesonide
93
What are the most common allergenic of the Class B steroids?
triamcinolone, desonide, gluocinolone, fluocinonide, halocinomnide and hydrocrotisone butyrate
94
What is the screening agent for Class C steroids?
Betamethasone
95
What is special about the class C steroids?
Least allergenic: betamethasone, desoximetasone, dexamethasone
96
Screening agent for Class D steroids?
Hydrocortisone - 17-Butyrate
97
What steroids are included in Class D?
mometasone, aclomethasone, betamethasone valerate, and clobetasol
98
Delayed reading is important for what class of steroid?
Class D
99
What two steroid classess cross-react with each other?
B and D
100
What is the most common sunscreen allergen?
Oxybenzone
101
What things does poison ivy cross react with?
Japanese laquer tree, cashew nut, mango, ridnd leaves sap, indian marking nut, ginkgo, brazilian pepper tree
102
Where does the sensitizer pinaceae come from?
Pinus palustris (pine tree)
103
What does pinaceae cross react with?
balsam of peru, turpentine, colophony, benzoin, wood tars, spices
104
What is the sensitizer sesquiterpen lactone (of the asteraceae compositae group) from?
ragweek, dandelion, pyrethrum, mugwort, chrysanthemum, wees, feverfew, artichoke, daisy, sunflower, endive, arnica, marigold, chammomile
105
What do the asteraceae compositae cross react with?
permethrin
106
What is the sensitizer for the plant aliaceae?
Diallyl disulfide
107
What things are diallyl disulfide in?
Onions, garlic, chive
108
What is the sentizer in the plant primulaceae?
Primin
109
What plants is primin in?
primrose
110
What is the sensitizer for the myrtaceae plants?
D-limonene
111
What things is D-limonene in?
tea tree oil/malaeuca oil
112
What is the senitizer for the anacardiacea family, toxicodendron species?
Urushiol (an oleoresin)
113
What plants have urushiol?
poison ivy/poison oak/ poison sumac (in the leaves, stems and roots
114
What type of dermatitis does the asteraceae (compositae) plants cause?
usually airborn allergic contact dermatitis. This involves eyelids, melolabial folds, submental/retroaricular sulci/ anecubital fossae
115
How long after re-exposure to an allergen does it take to get rash?
Within 48 hrs
116
How frequently do you have to be exposed to an allergen to maintain an allergic contact dermatitis?
As little as once every 3 weeks
