Hypersensitivity Disorders Flashcards
Food-Dependent, Exercise-Induced Anaphylaxis (FDEIA)
This occurs only when the patient exercises within 2 - 4 hours of ingesting food, but in the absence of exercise, the patient can ingest the food without any apparent reaction. This disorder appears to be more common in females than males, with the highest prevalence in the late teens to mid-30s.
Paper wasp nest
Carba mix
The common source of exposure is rubber accelerators
Difference between scleritis vs. episcleritis
Scleritis is differentiated from Episcleritis by symptoms of severe pain ( often described as deep and boring). Additionally, all redness of episcleral origin will blanch within 20 minutes of application of a single drop of 10% phenylephrine. 40% of patients with Scleritis also have a systemic disease like RA.
Key Fact: The mainstay of treatment for all types of Scleritis has typically been oral nonsteroidal agents, oral steroids, or oral immunosuppressive agents. Steroid eye drops are considered to be infective.
Which immunoregulatory abnormality is present in AD?
Increased expression of CD23 on B cells and monocytes.
What immunopathologic abnormality is seen in AD?
Keratinocyte apoptosis causes acantholysis and spongiosis.
Airway smooth muscle:
Contraction
Histamine, cys-LT, kinin, prostanoid, endothelin
p-Phenylenediamine
Permanent hair dye, henna
What is the only member of the lipocalin class that is a food allergen is the cow’s milk protein?
Bos d 5
(Cow’s milk Bos d 4 - 8)
Yellowjacket nest
Which medication that can be used as an alternative therapy in antihistamine refractory chronic urticarial is preferred in urticarial vasculitis, delayed pressure urticarial, and angioedema?
Dapsone
There is limited evidence on the use of dapsone in chronic urticaria, especially in neutrophilic urticarial. Dapsone is preferred in the treatment of urticarial vasculitis, delayed pressure urticarial, and angioedema. Patients on dapsone should be monitored for anemia, neuropathy, and methemoglobinemia.
Unlike in irritant contact dermatitis, the borders of the lesions in allergic contact dermatitis are _________ defined. In ACD, additional lesions __________ appear on other parts of the body that have not come into contact with the allergen.
Poorly; can
“Wet work”
2 hrs/day, or use occlusive gloves longer than 2 hrs/day, or clean the hands very often (eg 20 times/day or less if cleaning procedure is aggressive)
Which cytokines are secreted less by Th1 cells in AD?
IFN-gamma
LTPs
Removal of outer layers by physical or chemical peeling leads to loss of LTPs located in the outer layer. Thus, peeling fruits makes them safe for consumption by certain individuals with LTP allergies.
Preparation of pasteurized, ultrahigh temperature treated fruit juices is NOT sufficient to make them safe for individuals with LTP fruit allergies as the fruit LTPs retain a native-like structure.
Lifetime therapy with venom immunotherapy
- Honeybee allergy
- Life-threatening reaction
- Significant systemic reaction from sting or IT
- Increased baseline tryptase
Which pathogen is most often associated with AD?
HAE with normal C1 INH
- It is more likely to affect females
- It is less likely to manifest before puberty
- Patients tend to have fewer attacks, with more attack-free intervals
- The distribution of attacks includes a higher percentage of facial and tongue episodes, a lower percentage of abdominal episodes, and fewer multiorgan attacks.
White-faced Hornet
Yellowjacket
Steroid Potency
Age-appropriate indications when treating pediatric patients:
- Fluticasone 0.05% cream, up to 28 days of in children age > 3months
- Fluticasone lotion in children age > 12 months
- Mometasone ointment in children > 24 months.
Loss-of-function mutations in FLG are strongly associated with a risk of ______ when
occurring with atopic dermatitis.
asthma
CIU nonresponders
CIU nonresponder basophils do not degranulate to ex vivo IgE receptor activation and have elevated levels of IgE receptor regulating inhibitor phosphatases, SHIP-1 and SHIP-2.
Sweat bee
What is the lifetime prevalence of atopic dermatitis in U.S. schoolchildren?
17%
Paper wasp
The highest incidence of asthma at a given age has been observed in children with the onset of AD before?
3 months
FPIAP
- Cow’s milk – 76 percent
- Egg – 16 percent
- Soy – 6 percent
Cow’s milk and soy protein-induced proctocolitis generally resolve within 6 months to 2 years of allergen avoidance, though refractory cases may be seen.
In particular, in contrast with FPIAP, infants with FPIES typically present with severe symptoms (vomiting causing dehydration, abdominal pain, fever, or voluminous watery diarrhea) beginning within hours after the ingestion of the offending antigen.
What is the most common form of HAE?
Type I (85% of the cases)
Type II accounts for 15% and because of the lack of clear diagnostic criteria for HAE with normal C1 INH level, no estimates can be made regarding its overall prevalence or distribution.
Acquired C1 INH deficiency is a sporadic disease. It is relatively rare, with an estimated prevalence between 1:100,000 and 1:500,000, although many cases may not be recognized or diagnosed.
Airway smooth muscle:
Proliferation
PDGF, EGF, endothelin-1
Which cytokines are upregulated in AD?
IL-4, IL-5, and IL-13
The fundamental abnormality in both type I and type II HAE is a mutation of _________
C1 INH gene (SERPING1)
In patients with Uveitis which location is generally the most affected?
Anterior uveitis accounts for about 70%, intermediate 20%, and posterior 5%-10%.
Which agent is preferred for long-term HAE prophylaxis during pregnancy?
Plasma-derived C1INH is preferred if long-term prophylaxis is required
Airway smooth muscle:
Secretion
cytokines, chemokines, prostanoids
What is the average prevalence of contact allergy to at least one contact allergen?
19.5%
Which vaccines are contraindicated in persons with a history of urticaria, angioedema, asthma, or anaphylaxis to egg proteins?
Yellow fever and rabies
Which of the following allergens is most responsible for clinical reactivity to egg in egg-allergic children?
ovomucoid (Gal d 1)
Which gene mutation has been associated with early-onset, severe, and persistent atopic dermatitis?
FLG
Yellow Hornet
Bumblebee
Key Fact: Bumblebees are docile, slow, and relatively easily avoided
Airway smooth muscle:
Secretion
cytokines, chemokines, prostanoids
CCR4 binds with which chemokine in skin homing?
CCL17/TARC
FPIES
Acute: Onset of severe repetitive vomiting and/or diarrhea, lethargy, pallor, hypothermia, hypotension, abdominal distention within 1 - 3 hours after ingestion
Can occur with the reintroduction of a chronic FPIES trigger
Chronic: Intermittent, chronic vomiting, chronic watery diarrhea with blood/mucus, lethargy, pallor, weight loss, FTT
Elevated neutrophil count
Fire Ant nest
Along with IL-5, this cytokine contributes to increased survival and infiltration of eosinophils in AD?
GM-CSF
In chronic atopic dermatitis, monocytes have a lower incidence of spontaneous apoptosis due to increased production of GM-CSF. Along with IL-5, GM-CSF also contributes to the proliferation and survival of eosinophils.
Honeybee nest
Acute contact dermatitis caused by chromium (VI) (CrVI) has long been a recognized occupational problem, especially from exposure to?
Wet cement
Other sources of chromate exposure include contact with leather tanned with salts containing chromate and this has become increasingly recognized
Linear vs. Conformational epitope
Linear epitope → more prolonged allergy; allergen is stable and persistent.
Conformational epitope → mild, transient allergy.
Decreased levels of this protein have been associated with reduced water-binding capacity and increased transepidermal water losses in atopic dermatitis patients.
Ceramide
Airway smooth muscle:
Contraction
Histamine, cys-LT, kinin, prostanoid, endothelin
Airway smooth muscle:
Neurogenic Inflammation
Sensory nerves release S P and CGRP to act on inflammatory cells
Key Fact: Inflammatory cells release neurotrophins to act on sensory nerves.
Acute treatment of HAE attacks
Plasma-derived C1INH, ecallantide, icatibant, and recombinant human C1INH
Key Fact: Plasma (solvent detergent treated) may occasionally induce an acute exacerbation of the attack, presumably because plasma contains high molecular weight kininogen in addition to C1INH. For this reason, caution is required with the use of plasma to treat an HAE attack
There is high cross-reactivity between cow’s milk proteins with other animals’ milk from EXCEPT
Camel and donkey
Airway smooth muscle:
Neurogenic Inflammation
Sensory nerves release S P and CGRP to act on inflammatory cells
Key Fact: Inflammatory cells release neurotrophins to act on sensory nerves.
For the highest sensitivity, the C1INH function should be measured by what type of assay?
The chromogenic assay
It measures the inhibition of C1s activity by C1 inhibitor. ELISA assay detects the complexes formed between C1INH and C1r or C1s following activation of C1.
Yellowjacket nest
Which characteristic is typical of polymorphic eruption of pregnancy (PEP), also called pruritic urticarial papules and plaques of pregnancy (PUPPP)?
Dermatitis begins as erythematous papules within abdominal striae with periumbilical sparing that then spread to the extremities and coalesce into urticarial plaques. Lesions can be target-like and usually spare the face, palms, and soles.
Of note, because of limited safety data, only loratadine and cetirizine are currently
recommended for use in pregnancy.
Airway smooth muscle:
Proliferation
PDGF, EGF, endothelin-1
In Th2 driven skin disease such as atopic dermatitis, increased IL-4 and IL-13 can contribute to increased risk of infection through which mechanism?
Th2 cytokines IL-4 and IL-13 suppress keratinocyte production of defensins and cathelicidins. This is thought to play a role in the increased susceptibility to infections seen in Th2 mediated skin disease ie atopic dermatitis.
Which condition is characterized by fever, urticarial, and monoclonal gammopathy?
Schnitzler syndrome
Schnitzler syndrome is a rare systemic disorder in patients with monoclonal IgM or IgG (monoclonal gammopathy). Patients have associated symptoms of fever, weight loss, bone pain, adenopathy, and urticaria thought to be secondary circulating immune complexes and complement activation.
In skin-homing, 1,25(OH)2D3 and IL-12 increase expression of which E-selection ligand on lymphocytes?
CLA
In skin draining regional lymph nodes, 1,25(OH)2D3 and IL-12 induce expression of the E-selectin ligand cutaneous lymphocyte antigen (CLA) on effector T cells. Along with other home signals (CCR4, CCR8, CCR10) CLA direct migration of effector T cells to the skin.
What is the treatment for eczema herpeticum also called Kaposi varicelliform eruption?
Initial management usually requires systemic acyclovir. Recurrent cutaneous herpetic infections can be controlled with daily prophylactic oral acyclovir.
Honeybee
Quaternium 15
Preservative
Major Allergens in Flying Insects and Fire Ants
Which medication is both Histamine H1 receptor Antagonist and Mast Cell stabilizer?
Azelastine
Which lymphocytes are predominately seen in acute and chronic AD lesions via immunohistochemical staining?
CD3, CD4, CD45RO
By inhibiting the calcium-calmodulin dependent phosphatase calcineurin, tacrolimus ultimately prevent the translocation of which transcription factor?
NFAT
Baboon syndrome
Systemic contact dermatitis
