Chapter 5. Hypersensitivity Disorders Flashcards
What does ICD feel like, relative to ACD
stinging and less pruritic
almost immediate reaction
decrescendo pattern (decreases in severity between readings)
+++, ++, +, +/-
+++
T/F the degree of skin test sensitivity correlates well with degree of sting reaction
False, of course
What is photocontact dermatitis
What are some examples of photoallergic chemicals
What are some examples of phototoxic chemicals
photoallergic or phototoxic chemical that requires light-induced excitation in UV spectrum to cause dermatitis
photoallergic (requires prior sensitization) - PABA, chlorhexidine, thiourea, NSAIDs, thiazide diuretics, dapsone, sulfonylureas
phototoxic (no prior sensitization) - psoralens, furocoumarins, tar, lime, celery, parsnip, tetracyclines, amiodarone, diuretics, quinine, and NSAIDs
What are some examples of nonimmune-mediated adverse food reactions that are additive/toxins (not host-specific)
food poisoning, monosodium glutamate (MSG - numbness), sodium metabisulfite (bronchospasm)
Review recommendations based on skin history and results of testing
There are 2 insect allergens for ants. What are they
Sol i 1
Sol i 3
What is the protein for fish
Gad d 5
What is the species name for bumblebee
Bombus species
not aggressive, have subterranean or concealed nests
What are some examples of nonimmune-mediated adverse food reactions that are psychologic
food aversion, anorexia
There are 3 insect allergens for hornet/yellow jacket. What are they
Ves v 1
Ves v 2
Ves v 5
frequently cross reactive
Bonus round - systemic reactions from venom stings are reported in what percentage of adults and kids
How many fatal stings per year
3% adults
0.4-0.8% kids
40 fatal stings per year, half are in folks with no history of allergic reaction to stings
What are some characteristics of honeybees and their stings
domestic not particularly agressive, but females sting when provoked
Africanized killer bees - very agressive. tend to swarm and sting in large number
die when they sting
What is the protein for soy
Gly m 5
in children, what are the causes of 90% of food allergies (8)
cow’s milk, hen’s egg, soybean, wheat, peanut, tree nut, fish, and shellfish
What is the protein for egg
Gal d1-5
What cells mediate contact hypersensitivity
type IV hypersensitivity
mediated by CD4 and CD8 lymphocytes, stimulated by Langerhans and dermal dendritic cells
What are the predominant histologic features of contact dermatitis
lymphocytic infiltration
spongiosis
What is Frey’s syndrome (auriculotemporal syndrome)
transient, unilateral, and bilateral facial flushing or sweating after ingestion of spicy or flavored foods due to damage to the auriculotemporal nerve
what is the syndrome where patients exhibit symptoms of pruritis limited to the oral mucosa when eating fresh fruits and vegetables
pollen-food allergy syndrome
What are reasons to continue VIT indefinitely
severe initial reaction, systemic reactions to injection or sting while on shots, honeybee, (elevated tryptase)
What is the protein for peanut
Ara h 1-11
What percent of patients have positive serum but negative skin test to venom
10%
what medication has the alpha-gal carbohydrate group
galactose-alpha-1,3-galactose
this is a carbohydrate also found as part of the glycoproteins, including the chemotherapy monoclonal antibody cetuximab
What is the difference in presentation of normal and large local reactions to venom
normal = immediate, local, and transient erythema. Also edema and tenderness
large local = large surface area, peaking at 48 hours after sting. lasting one week
What are the major classes (3) of plant allergen
prolamin superfamily
cupin superfamily
PR10 protein family
what is “alpha-gal”
Galactose-alpha-1,3-galactose
urticaria, angioedema, or anaphylaxis 3-6 hours after ingesting beef, lamb, or pork. Not chicken. Associated with lone star tick.
Unlike common allergens, which are usually proteins, this is a carbohydrate
What is the protein for hazel nut
Cor a 8, 9
What is the protein for milk
Bos d4-8
What are paper wasps
subfamily Polistinae
Polistes species
nests are on eaves or window sills
What is Heiner’s syndrome
this is milk-induced pulmonary disease in infants. it is rare and not IgE-mediated
What are the three major families of animal food allergens
tropomyosin
parvalbumins/EF-hand proteins
caseins
What are some examples of nonimmune-mediated adverse food reactions that are pharmacologic
caffeine (jittery), tyramine in aged cheeses (headaches), scombroid fish poisoning (releases histamine-like chemicals)
What are characteristics of Vespula spp
yellow jackets
scavengers, aggressive, especially in the autumn when food supplies are scarce
sting for no reason at all
nests are concealed
most common cause of stings
like to hide nests in wall cavities, underground, or decaying logs
There are 5 major insect allergens for Honeybee. What are they
Api m 1
Api m 2
Api m 3
Api m7
Api m 10
What are the 4 etiologic categories of contact hypersensitivity
Allergic Contact Dermatitis
Irritant Contact Dermatitis
Photocontact Dermatitis
Contact Urticaria
What family of bees are yellow jackets and hornets
subfamily Vespinae
can sting repeatedly without losing sting apparatus
agressive
What are WBEs and what are they good for
“whole body extracts”. They are good for fire ants but terrible for flying hymenoptera (not enough venom in them)
what is the efficacy rate for VIT
what is a VIT maintenance dose
75-95% efficacy for preventing a systemic reaction
100 mcg venom (single antigen)
300 mcg venom (mixed vespids)
0.5ml of a 1:10 to 1:200 wt/vol extract given monthly (fire ant)
What technique is used for venom intradermals
concentrations between 0.001 and 0.01 micrograms/mL, increase in tenfold increments until positive or a max concentration of 1 mcg/mL is reached
+++, ++, +, +/-
+
What percentage of patients have a positive skin test to venom but negative serologic testing
20%
in other words, don’t trust serum alone
what is gustatory rhinitis
runny nose from spicy or hot foods
Where do yellow jackets (vespula) hide out
garbage cans, around food, empty soda cans
What is the “order” of stinging insects we care about
Order Hymenoptera
What causes irritant contact dermatitis (ICD)
is previous sensitization required?
most prevalent form of contact dermatitis
induced by chemicals, oxidants, alkali, surfactants, solvents that directly damage the skin
previous sensitization not required
What are Class 2 Allergens
these allergens are formed primarily from respiratory sensitization
sensitization to labile proteins encountered via the respiratory route, like pollens, results in IgE antibodies that recognize homologous epitopes on food proteins from plants
What is the protein for shrimp
Lit v 1, Pen a 1
+++, ++, +, +/-
++
Why not keep testing venoms at concentrations > 1 mcg/mL
false positives due to irritant effects
What is in fire ant venom (key fact)
95% piperidine alkaloids
sterile pustules within 24 hours post sting
What are some examples of nonimmune-mediated adverse food reactions that are metabolic
lactose intolerance, fructose intolerance, alcohol intolerance
How dangerous is rush venom compared to standard
not much higher than traditional regimens in more recent studies
Once sensitized, how long is contact dermatitis delayed upon re-exposure
12-48 hours
What family are stinging ants
Family Formicidae
+++, ++, +, +/-
+/-
Review the scoring system for patch test reactions
Contact Urticaria
can be either immunologic or nonimmunologic
IgE dependent - dairy, seafood, fruits, grains, topical antibiotics, metals, preservatives, and plants
IgE independent - fragrances, arthropods, jellyfish, and coral
what percent of children <5 have food allergy
6%
What percent of the general population has food allergy
3.5-4%, mostly shellfish in adults
When do you discontinue VIT
generally after 3-5 years
What are some stats on VIT safety
during buildup, 50% of patients have large local reactions and 5-15% have systemic symptoms. The majority are mild. <5% require epi
Allergic Contact Dermatitis (ACD)
- what locations are typically involved
- what is the typical pattern of positive reactions
- itch?
normally on hands, generalized, face, eyelids
crescendo phenomenon where positive reactions to patch test become more marked between first and second readings
severe itch which takes 12-48 hours to develop
What are Class 1 Food Allergens
primarily food that is ingested (GI sensitized).
can also invade through the skin
examples are cow’s milk protein (casein and whey), egg (ovalbumin and ovomucoid), peanut (vicilin, conglutin, and glycinin), fish (parvalbumin), shellfish (tropomyosin)
There are 3 insect allergens for paper wasp. What are they
Pol a 1
Pol a 2
Pol a 5
What is the protein for apple
Mal d 1,2
Explain the practical aspects of patch testing
patch is placed on day 1, read and removed on day 3, and again on day 5
What patients should definitely get venom prick testing
Arguably patients with history of severe anaphylaxis who may be extremely sensitive to venom
What is the fancy/scientific name for the honeybee
Apis Mellifera
note the beeswax nest has numerous vertical combs
name five of the top ten contact allergens in the United States
nickel, neomycin, balsam of Peru, fragrance mix, thimerosal, sodium gold thiosulfate, quaternium-15, formaldehyde, bacitracin, cobalt chloride
What is Potassium Dichromate used in
stainless steel, chrome plating other metals, tanned leather
what are chromates used in
textiles, leather tanners, and construction worker using wet cement
what is Cobalt dichloride used in
(uncommon)
dental implants, artificial joints, engines or rockets
what is nickel used in
jewely, dimethylglyoxime test of nickel-containing material (pink=positive)
what is Toxicodendron dermatitis
what is it cross-reactive with
secondary to poison ivy, oak, sumac
usually develops after several encounters with plants, sometimes years after exposure
10-15% of population highly susceptible and will have systemic symptoms
cross reactive with mango peels
Which fraction of a plant contains the sensitizing substances in ACD
oleoresin fraction
most of the time plants have to be crushed to release these antigenic chemicals
What plant causes the most hand eczema in flower workers in the United States
Alstroemeria, also called Peruvian lily
classic dermatitis that is very itchy and affects the first three fingers and exposed areas of dorsal hands, forearms, V-region of the neck, and the face
What is Balsam of Peru used in
it is used in the manufacture of pefumes, but also a flavoring agent. Has wide cross-reactivity, most prominently with cinnamon and vanillin.
What two broad categories of preservatives are there
formaldehyde donors (high prevalence of positive patch tests to these, and most fabrics contain these)
nonformaldehyde donors
What preservative is the most frequent cause of ACD in the US
Quaternium-15
formaldehyde donor
What type of products are second only to skin care products as the most common cause of cosmetic allergy
hair products
cocamidopropyl betaine
important allergen that is in shampoos, eye/face cleaners, bath prodcuts
paraphenylenediamine (know this)
most common cause of contact hypersensitivity in hair dressers
glycerol thioglycolate
found in permanent wave hair products
ethylacrylate
has been demonstrated to detect a higher number of acrylate-allergic patients.
acrylics are in nail products
what type of contact dermatitis do sunblocks/sunscreens cause
photoallergic ACD
topical corticosteroids
- what are most common screening agents in patch testing
- how are they classified
can cause ACD
test them 7 days after application
- budesoinde and tixocortol pivalate 1%
- Group A hydrocortisone type
- Group B triamcinolone type
- Group C betamethasone type
- Group D hydrocortisone-17-butyrate type
epoxy resin
when cured is nonsensitizing
ACD occurs to uncured resin or to hardener
colophony
type of resin made from pine trees. appears in cosmetics, topical meds, and industrial products. may cross-react with Balsam of Peru
what kind of products have ethylenediamine dihydrochloride
topical creams, aminophylline, generic nystatin
EDTA does not appear to cross react
paraphenylenediamine
benzene derivative and common, epidemic with henna tattoos. this is what people with allergies to henna tattoos are actually reacting to
topical antibiotics (resin)
common and iatrogenic with risk of anaphylaxis that can be delayed
neomycin is crossreactive with bacitracin
what is systemic contact dermatitis (SCD)
generalized ACD rash from systemic administration of a drug, chemical, or food to which the patient previously experienced ACD
for example, patients who had ACD to topical benadryl can get SCD when given IV benadryl
baboon syndrome - indurated erythema that appears in the groin of afflicted patients
What are symptoms of EoE
GERD. intermittent vomiting, abdominal pain, dysphagia, food impaction, irritability, food avoidance, insomnia
What is required for definite diagnosis of EoE
15 eosinophils/hpf
T/F Most children who are unable to consume nonbaked forms of eggs and milk are able to tolerate baked egg and milk
True
which type of Th response is expected for hypersensitivity pneumonitis (Th1, Th2, or Th3?) Which type of cell is expected
note that chronic HP switches to Th2 type
review the presentation of acute, subacute, and chronic HP
review important HP associations
T/F - cigarette smoking is protective for HP
True for acute.
somehow the smoking inactivates the macrophages in lungs.
However, smoking can worsen chronic disease
review lab findings in HP
what kind of PFT findings would you expect
restrictive
over time, with progressive chronic disease, can become obstructive
review differential of HP
pay attention especially to organic dust toxic syndrome
