Allergy & Immunology Flashcards

Question

Allergic Rhinitis exam features/sequelae/diagnostics

Answer 1

**Exam features:** nasal crease, allergic shiners, allergic salute **Concerning sequelae**: Chronic OME; frequent AOM Sinusitis Nasal speech Mouth breathing secondary to enlarged tonsils and adenoids; high arched palate, malocclusion Snoring, poor sleep Nasal polyps- rare in children except CF pts **Diagnostics:** Clinical diagnosis - usually need 1-2 seasons of exposure Serum labs can be normal in children w/ AR Cytology testing of nasal secretions is available, not routinely done in primary care Skin testing or serum IgE testing can identify environmental factors to help guide mitigation strategies

Answer 2

**Environmental control ** Frequent laundering of bed linen, limiting stuffed animals & pets in the bedroom; pest control Utilize air filters, dehumidifiers to combat mold **Avoidance of triggers when possible** Less outdoor play during high pollen times Immediate removal of clothing and showering after outdoor exposures **Pharmacologic** - Antihistamines- cetirizine, loratadine, fexofenadine - Nasal steroids (pt should fully evacuate nose prior to use)- Fluticasone propionate (4 yrs+), mometasone, triamcinolone (2 yrs +) - Leukotriene receptor antagonist- montelukast - Decongestants- short term use, ensure age appropriate dosing Long term use can lead to rebound congestion, can cause hyperactivity and irritability in children Not recommended under 6 yrs If first line treatment fails or effects wane- referral may be necessary for skin testing

Answer 3

IgE mediated type I & cell mediated type IV reaction → results in inflammatory changes in epidermis Mutation of filaggrin gene (FLG) → results in loss of function leading to entry of allergens and transepidermal water loss Triggers: airborne allergens, food, contact allergens, infectious agents

Answer 4

(Criteria for diagnosis by Hanifin & Lobitz) Essential features: - Pruritus, eczematous dermatitis in age specific pattern - Chronic or relapsing Important features: - Early age at onset, atopy, xerosis Common associated features - Atypical vascular response; keratosis pilaris, ocular changes, lichenification

Answer 5

**Infants and toddlers** May appear as a rash on the scalp, face or arms and legs **Children** May begin inside creases of the elbow or knees, the neck, wrists, ankles, and/or the crease between the buttocks/legs **Adults** Often shows on the inner creases of the elbows or knees, hand, and/or nape of the neck

Answer 6

**Differentials**: Scabies Seborrheic dermatitis Psoriasis Histiocytosis X Severe combined immunodeficiency Acrodermatitis enteropathica **Diagnostics:** Not necessary for diagnosis, can be considered if there is coinciding asthma or allergic rhinitis and you want to identity triggers Refractory cases may require testing to identify underlying genetic conditions Skin culture if secondarily infected- impetigo, mrsa Biopsy rare but can be useful

Answer 7

**Dry skin** Moisturizers Emollients in either cream or ointment form Shortened bath times, use of mild soaps **Inflammation** Topical corticosteroids creams or ointments Nonsteroidal immunomodulators **Pruritus**- consider oral antihistamine- mixed data on effectiveness Hydroxyzine or diphenhydramine at bed time **Behavior modification** - rubbing instead of scratching, socks or mittens at bedtime, keep nails trimmed **Nonsteroidal options** (after first line of moisturization and second line of mild/medium potency steroid) Calcineurin inhibitors: Tacrolimus and Pimecrolimus Black box warning - increased risk of cancer associated with oral, topical has been found safe to date Safe to apply on body and face for mild-moderate AD Phosphodiesterase-4 (PDE-4) inhibitor- Crisaborole Anti inflammatory and anti-itch Burning or stinging common side effect **Home interventions** Wet wrap therapy- put on layer of lukewarm wet clothing, and put dry layer overtop Cut fingernails short Teach to pat/rub and not scratch Avoid food triggers once identified- hydrolyzed formula for infants w/ mild protein allergy Moisturize often Refer if: → Dermatology or allergist: No response to first or second line therapy If has HPV or Molluscum contagiosum involvement Severely infected may require hospitalization for IV abx: - Staphylococcus - Eczema herpeticum/ kaposi varicelliform eruption

Answer 8

Low potency: Desonide 0.05% Hydrocortisone 0.5-2.5% Medium potency: Bethamethasone valerate 0.1% Triamcinolone acetate 0.1%, 0.5% Flurandrenolide 0.05% Flutcasone proprionate 0.05% High potency: Betamethasone diproprionate 0.05% Clobetasol proprionate 0.05% Halobetasol proprionate 0.05%, 0.25% Flucinonide 0.05% generally limit high potency TCS to < 2 weeks duration gel formulation are highest potency

Answer 9

Rash produced by capillary leak vasodilation & edea of skin Occurs as a result of histamines, prostaglandins, and leukotrienes being released from epidermal mast cells Triggers: IgE mechanisms, viral, bacterial, parasitic, and fungal infections, collagen vascular disease, malignancy, endocrine disease, and physical factors like heat, cold, pressure, sun, vibration Erythematous, popular, coalesce, blanching, last <24 hrs but can recur, itchy

Answer 10

Extension of uritcarial process deeper into the dermis +/- mucous membrane involvement tissue swelling, tightness involvement of abdominal viscera results in colicky abdominal pain

Answer 11

Eliminate offending agent Manage underlying infections Manage underlying condition Medications - Antihistamines 1st (diphenhydramine) and 2nd gen (claritin, zyrtec, allegra) - H2 receptor antagonists- cimetidine, famotidine, ranitidine (helpful for GI manifestations) - systemic steroids (for angioedema)

Answer 12

most common: milk, egg, wheat, soy - resolve in childhood peanut, tree nut, shellfish, fish- can resolve, but more likely to be persistent Clinical manifestations: suspect when the following are present within minutes or hours after food ingestion- - Urticaria - Edema - Wheezing - Mouth itch- children may not verbalize but will rub tongue against top of mouth, or click with tongue - Cough - Nausea / vomiting - Anaphylaxis

Answer 13

- based on history & clinical presentation - medically managed food challenge is the most definitive test for food allergy - food specific IgE testing (should not be sole source used for diagnosis) In children w/ **moderate** to **severe eczema** that are **< 5 yrs**, food allergy should be considered for **milk, wheat, peanut, egg, and soy** if at least 1 of the following are met - The child has persistent AD in spite of optimized management and topical therapy - The child has a reliable history of an immediate reaction after ingestion of a specific food

Answer 14

Infant w/ severe eczema, egg allergy, or both- consider eval by IgE and/or skin prick test (SPT), if necessary OFC, based on results, introduce peanu containing food (4-6mts) Infant w/ mild to moderate eczema- introduce peanut containing food (6 mts) Infant w/ no eczema or food allergy- introduce peanut containing food at any age appropriate time

Answer 15

Multisystem reaction that occurs suddenly after contact w/ a substance/mechanism Constellation of symptoms involving multiple organ systems: **Skin (90% of cases)**- flushing, pruritus, urticaria, angioedema **GI (30% of cases)**- nausea, abdominal pain (colic), vomiting (large amounts of “stringy” mucus), and diarrhea **Respiratory (70% of cases; most common cause of death in children)** - laryngeal: pruritus and “tightness” in the throat, dysphagia, dysphonia and hoarseness, dry “staccato” cough. - Lung: dyspnea, chest tightness, “deep” cough, and wheezing; - nose- pruritus, congestion, rhinorrhea, and sneezing **CV (20% of cases)**- feeling of faintness, syncope, chest pain, dysrhythmia, hypotension, shock

Answer 16

Highly likely when 1 of the following 3 criteria are met **Criterion 1**: acute onset (minutes to several hours) with *involvement of skin, mucosal tissue*, or both, *even in the absence of known or suspected trigger* and at least* one* of the following: - Respiratory compromise - Reduced BP or associated symptoms of end-organ dysfunction (collapse, syncope, incontinence) **Criterion 2**:* two or more *of the following occur rapidly (minutes to several hours) after *exposure to a likely allergen* - Involvement of the skin or mucosal tissue - Respiratory compromise - Reduced BP or associated end-organ dysfunction - Persistent GI symptoms **Criterion 3**: reduced BP rapidly (minutes to several hours) after exposure to known allergen

Answer 17

Uniphasic - anaphylactic reaction, treated, and pt improves Biphasic (up to 14% of cases) Develop initial symptoms Appear to recover Develop symptoms again Protracted- lasts 1 day-3 weeks

Answer 18

1. Assess airway, breathing, circulation, and neuro status - continue to monitor throughout 2. Place in recumbent position 3. Administer Epinephrine IM - do not wait for symptoms development -administer at onset of mild symptoms (pruritus, urticaria, etc.) - may use epipen or epi vial Child - **0.1mg/kg/dose IM/SC** up to max of 0.5mg/dose q20 min- 4 hrs prn Adult - **0.1-0.5 mg IM/SC** q20min-4 hr prn; may increase to single max dose of 1 mg 4. Administer supplemental O2 in patients w/ respiratory symptoms 5. Bolus of NS (20-40 ml/kg) in patients w/ hypotension Second line therapies: - antihistamine (diphenhydramine 1-2mg/kg) - steroid (oral prednisone or IV methylprednisolone at 1-2 mg/kg/dose) - inhaled SABA for wheezing **Discharge**: Mild anaphylaxis- 4-6 hrs observation Moderate anaphylaxis- 6-8 hrs observation Severe anaphylaxis- admit for at least 24 hrs obs Diagnostics for unknown cause Trigger avoidance education Auto injector epinephrine (AIE) prescription for 2 autoinjectors - **<30kg: 0.15 mg (epipen junior)** -** >/=30kg: 0.3 mg** Educate to seek immediate medical attention anytime anaphylaxis occurs Written emergency plan

Answer 19

Cutaneous and mucosal hypersensitivity reaction w/ characteristic lesions triggered by a stimuli Lesions appear on the skin favoring the extremities and usually resolve within 7-21 days Mucous membranes are involved in about 10% of cases Etiology: HSV (likely to re occur in pts), mycoplasma pneumoniae, other virsues, bacteria, fungi, drugs, heavy metals, herbals, topical therapies, poison ivy Increased risk: HIV, corticostroid therapy, immunosuppresion, BMT recipient, Lupus

Answer 20

Typical skin lesions w/ symmetrical acral (peripheral) distribution (limbs) Mucous membrane involvement is rare, only single mucosa, usually mouth Healing takes 2-3 weeks

Answer 21

Skin lesions are extensive but less than 10% of body surface area Typical target lesions present Mucosal involvement is severe and affects at least 2 mucosal sites Healing takes 4-6 weeks

Answer 22

Fever and feeling of unease prior to or accompanying the eruption Arthralgia, joint swelling Target lesion is typical- symmetrical, trunk is usually spared, some complain of burning sensation but no itching Mucosal lesions are most common in the mouth - Bullous then painful erosion - May note white coating Pulmonary system may be involved with cough, dyspnea (particularly w/ mycoplasma pna if that is trigger)

Answer 23

**Differentials:** Pityriasis rosea Urticaria Viral exanthems Stevens johnson syndrome Hypersensitivity reaction **Diagnostics:** Diagnosis is clinical Skin biopsy of lesion center Look for current HSV outbreak (oral and genital or other parts of the body) Consider CXR with cough, respiratory symptoms (M. pneumoniae) CBC/D - Mild leukocytosis - Neutropenia - Mild anemia Chemistry if concern for dehydration (d/t mouth lesions)

Answer 24

Topical treatment -antiseptics for bullous lesions - antiseptic mouthwash - anesthetic - topical steroid Ocular involvement- refer to ophtha M. Pneumoniae- azitrhomycin HSV- acyclovir Hospitalize for - dehydration - pain control - extensive lesions w/ burn like qualities- to decrease likelihood of secondary infection

Answer 25

Rare, acute, serious and potentially fatal skin reaction Characterized by sheet-like skin and mucosal loss accompanied by systemic symptoms Medications are the cause in over 80% of cases: anticonvulsants, allopurinol, sulfonamides, antibiotics, APAP, nevirapine, NSAIDs, contrast media

Answer 26

Begins w/ nonspecific symptoms like fever, malaise, URI symptoms Blistering rash and erosions appear to the face, trunk, limbs, and mucosal surfaces - erythematous, target like, annular, or purpuric macules - bullae - large painful erosions - Nikolsky positive- lateral pressure on the skin results in shedding of the epidermis Mucosal ulcerations involving the lips, mouth, pharynx, esophagus, GI tract, eyes, genitals, upper respiratory tract Patient is ill appearing and in pain Liver, kidneys, lungs, bone marrow, joints may be involved

Answer 27

**Treatment/ management:** Hospitalization- preferably burn care unit Cessation of causative drug Fluid replacement Nutritional support Temp control, pain control Supplemental O2 and ven support if needed Skin care Abx to treat secondary infections **Prognosis:** at risk for secondary infections & organ failure more common complicationsL blindness, scarring, renal scarring mortality up to 20%

Answer 28

IgA collects in small blood vessels → becomes inflamed & leaks blood Most common vasculitis in children (<10 yrs, males> females) Clinical findings: - may be proceeded by URI (likely trigger) - skin rash (palpable purpura to buttocks and LE) - arthritis (60-80%) - colicky abdominal pain (50-70%), may proceed rash - renal involvement (20-60%)

Answer 29

based on clinical presentation 2 or more of the following: -palpable purpura (usually to the LEs) -initial presentation at 20 yrs or younger -bowel angina (manifests as colicky abdominal pain) -typical renal biopsy findings

Answer 30

Diagnostics: UA and BP- monitor for renal involvement (baseline, then q month x 6 mts) Consider Stool guaiac for occult blood Abdominal CT (if obstruction suspected) Renal biopsy if -proteinuria > 1 mt -renal insufficiency -HTN -nephrotic syndrome Management -symptomatic , analgesics for mild joint pain - monitor for hematuria & proteinuria - monitor BP - refer/consult for GI, renal, significiant joint involvement usually runs its course within 3-4 wks, rash may recur for up to 1 yr