george f. kroker, md facaai diagnostic techniques for inhalant/environmental treatment

George F. Kroker, MD FACAAI

Diagnostic Techniques for Inhalant/Environmental Treatment

Copyright 2015 Allergy Associates of La Crosse

Tools of the Allergist--Inhalants Skin Tests

ScratchSkin Prick Test Intradermal (ID, IDT)

In Vitro TestsSpecific IgE

RAST (radioallergosorbent test) ELISA (enzyme-linked immunosorbent assay)

Total IgE, other immunological tests


Test Preferences—Vary by Specialty

Board Certified AllergistSkin Prick Test (SPT) Intradermal Test (ID) In Vitro Specific IgE

ENT Allergist Intradermal Dilutional Test (IDT)Modified Quantitative Test (MQT) In Vitro Specific IgE


Annals of Allergy101:580-592, 2008


The Importance of the History

“The clinical history drives the diagnosis of human allergic disease…the clinical history makes the critical link between the allergy skin or blood test results and the allergic disease”

Pearls and pitfalls of allergy diagnostic testing: report from the ACAAI/AAAAI Specific IgE Test Task Force. Annals of Allergy, Asthama and Immunology. Dec 2008;101:580-592.


The Importance of History (cont.) “Diagnostic tests should be used to support

or exclude a diagnosis of specific allergies based on the history. They should almost never be used as a substitute for a careful history…neither skin tests nor serum IgE tests should be either requested or interpreted outside the context of the clinical history and physical examination…”



The La Crosse Method Perspective We recognize that various allergy testing

techniques have their rightful place Our ultimate goal is to deliver SLIT

treatment at the optimum therapeutic level in a streamlined manner

Our testing protocols have been developed to provide a high degree of quantification of the patient’s sensitivities as efficiently as possible


Where are we now?

Optimized IDT: streamlined to reduce patient’s time in the office

Selective use of In Vitro testing Determine which specific SLIT protocol

is best suited for the patient Treat at the therapeutic dose Retest allergens being treated to

monitor effectiveness of current dose


How did we get here?

Brief review of skin testing techniques History of skin testing techniques Types of techniques Principles applicable to all techniques Advantages & disadvantages of each

technique


History of the Skin Test

Charles Blackley, MD 1820-1900

Daily Pollen CountsMay 28-Aug 1, 1866


Types of Skin Tests Epicutaneous

ScratchPrick-punctureModified prick

Intradermal Single strength Intradermal

Dilutional Titration (IDT)


Skin Testing: A Common Goal


Factors influencing skin test reactivity Age: Reactivity progressively increases

throughout childhood to about age 20-30, then gradually declines until age 50, after which the decline is more rapid

Menstrual cycle: Reactions to allergen & histamine larger at midcycle

Seasonal: Reactions to a seasonal allergen are greater just after the allergy season is finished

Sun Damage: Affects skin mast cell number


Factors influencing skin test reactivity

Site tested: Upper back > lower back> forearm

Clinical status on day of testing: Heavy allergen exposure immediately before testing can enhance reactivity

Other diseases: cancer, etc. Medications: Antihistamines, tricyclic

antidepressants, H2 antagonists reduce reactivity


Wait time for testing aftermed d/cFirst-generation H1 meds

>24 hrs

(hydroxyzine 72 hrs)

Second-generation H1

>72 hrs

H2 blockers <24 hrs

Tricyclic antidepressants

>7-14 days


Epicutaneous: Scratch Test Method: Knife blade or allergen abrades an area of

skin in linear fashion, producing a superficial scratch. Allergen extract applied.

Advantage: Time Safety

Disadvantage: Lack of uniformity of abrasion Uncomfortable & traumatic Increased false pos & false neg compared to

prick/puncture


Epicutaneous: Puncture Test

Method: Drop of extract is placed on

the skin Testing device (lancet,

bifurcated needle) placed perpendicular

to the skin Device is tapped gently

through the drop of extract, and held on the skin with pressure for about 1second


Epicutaneous: Modified Prick Test

Method: Drop of extract placed

on skin Needle is introduced

laterally into skin at an angle, through the drop

Skin is lifted up with no downward pressure introducing a minute amount of extract into

the skin


Stand-Alone Skin Prick Tests

Stand-alone SPT favored by many allergists for its specificity, safety, and efficiency

Reactions are graded based on wheal size, presence of pseudopods, and in comparison to pos/neg controls

Results graded from 1+ to 4+ Multi-prong device may be used to speed

application and provide consistency


Intradermal: Single-strength

“The value of prick tests is limited by low potency extracts producing false negative results.”

“Infrequently, an intradermal test will reveal a clinically relevant reaction in the case of a negative prick test.”

Allergy: Principles & Practice, 5th ed 1998E. Middleton Ed.



“Intracutaneous testing may be useful and should be pursued if the prick/puncture test is negative or equivocal to allergens strongly suggested by the patient’s history or exposure.”

Joint Task Force on Practice Parameters for the Diagnosis and Treatment of Asthma. Annals of Allergy, Asthma and Immunology. 1995;75: 543-625.


Intradermal: Single-strength Method: Testing performed with disposable

tuberculin syringe and small gauge needleA small amount (.02ml) of dilute extract is

injected into the superficial layers of the skin, making wheals approximately the same size



Advantage More sensitive than prick test

DisadvantageLess specific than prick testRate of systemic reactions, <0.5%Can cause large local reactionsFirst fatality reported 1922 fish ID injection


Epicutaneous Skin Testing

“Despite its widespread adoption as the premier method used in clinical practice, many characteristics of the skin prick or puncture test are poorly defined…it is concerning that a standard protocol for skin prick testing has yet to be universally adopted. Arcane systems are still being used to grade skin prick test wheal-and-flare responses (i.e., grade 1 to 4+) which greatly impedes communications of results between different clinics.”

The skin prick test: “more than meets the eye”David Bernstein M. Annals of Allergy, Asthma and Immunology. June 2003;92: 587-588. (Editorial)


Epicutaneous Skin Testing What do allergy skin tests really mean?

“Categorization of skin test results from 0 to 4+ is analogous to recording the results of a CBC and differential as a moderate white count with 2+ neutrophils, 3+ lymphocytes, and 1+ bands. One could argue that if we are only concerned about white blood cell counts that either are very low or very high, such categorization should be adequate. Even so, most physicians prefer to review the actual numbers so they can interpret the results themselves. Why should we not do the same for skin test results?”

What do allergy skin tests really mean? Portnory, JM. Annals of Allergy, Asthma and Immunology. 2002 Oct;89(4):335-6.


History of IDT 1911: Leonard Noon

injected allergy patients with pollen extracts (to induce production of pollen “antitoxin”)

Attempted to determine degree of sensitivity of his pts by making various dilutions of antigens and instilling them into the patient’s conjunctiva Leonard Noon MD

1878-1913


History of IDT Noon quantified a patient’s sensitivity by instilling

drops of different-strength pollen extracts into the conjunctiva of a known hay fever patient

The strength of extract required to produce a minimal reaction would then represent the patient’s “resistance”: i.e., if a dilution of four “units” was required to institute a reaction, the patient’s “resistance” was rated as 4

These quantified responses could then be used in selecting the appropriate dose for injection therapy


Noon’s Quantified Results


History of IDT

“Three quarters of a century later, a large percentage of the allergy world uses basically non-quantitative techniques of diagnosis and treatment…there is also considerable disagreement regarding an appropriate starting dose for therapy. It has been observed that should William Osler be returned to life, he would be unable to recognize most of the technology in use. If Leonard Noon returned, he could resume his practice as he left it with little difficulty. He would probably continue to seek better

quantification.”

Endpoint titration and immunotherapy. King HC. Otolaryngology Clinics of North America. 1985 Nov;18(4):703-17.


History of IDT

French K. Hansel MD1893-1981

Herbert J. Rinkel MD1896-1963


History of IDT (cont.) 1930: French Hansel was the first to perform

skin tests using multiple-strength individual extracts instead of single-concentration extracts

He used intradermal injections of antigens in serial 1:10 ratios of varying strengths while measuring the response

He demonstrated that each antigen has a unique response in a given patient

He found the strength of a response to different antigens is not the same for all the antigens encountered by a given individual


History of IDT (cont.) Hansel concluded that multiple intradermal skin

tests using individual allergens with varying doses produced greater accuracy of information regarding the degree of the patient’s sensitivity

1937: Herbert Rinkel, an allergist working with Hansel, found that an antigenic dilution ratio of 1:5 administered in progressively increasing increments was qualitatively and quantitatively superior in measuring allergic skin reactivity. The response was constant through 3 or 4 dilutions in 72% of patients


Goals of IDT Reliably identify an inhalant sensitivity by skin

testing Determine a safe starting point at which to initiate

therapy (the “threshold dose”) Allow treatment to be started during patient’s peak

allergy season Treat a variety of allergens of different degrees of

sensitivity in a single mix by varying the concentration of individual antigens according to the skin test reactions (“Multi-antigen threshold therapy”)


Principles of IDT IDT is based upon the interpretation of the

skin response to the injection of weak (nonreacting) dilutions of antigen, proceeding to stronger (reacting) dilutions of the antigen

The first test producing a wheal 2 mm larger than the preceding non reacting wheal is considered the endpoint of the reaction

Treatment based on the endpoint response is within a safe and therapeutic range


IDT: Standard Technique Allergenic extracts are prepared using 5-fold

serial dilutions (Concentrate to a #6)


LCM Serial Dilutions


LCM Concentrates & No 1 dil


IDT: Standard Technique The antigen is injected intradermally, creating

a demarcated 4mm wheal containing approx .01 ml of the appropriate dilution

The number 6 dilution of each antigen is administered

The response is measured at 10 min


IDT: Technique


IDT: Standard Technique The wheal will normally grow to 5mm within 10

minutes If less than 2mm growth, the result is interpreted

as negative and a stronger dilution is applied The first dilution to establish a 7mm wheal is

considered the “endpoint” Confirmation: show a clear progression of wheal

size of 2mm over 3 consecutive dilutions


IDT: Typical Std Titration Results

# 6 # 5 #4 #3 #2 #1

4 4 5

9

9

Endpoint

5 5 7

7

Endpoint


IDT: Std Titration


IDT: Standard Technique

This process may take several hours and/or 2 or more sessions depending on the number of allergens being tested, the severity of reactions, abnormal skin or whealing responses, etc.


La Crosse Method: Optimized IDT Technique of administration of antigens is identical

to standard titration, except for starting dilution In contrast to giving a number 6 starting dilution

for all antigens, varying-strength starting dilutions are used for different antigens, based on clinical experience and the patient’s own history

Goal: to find 2 mm wheal growth response (i.e, 7mm wheal in 10 minutes) with further confirmation by giving additional selected test dilutions as needed


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Birch

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Ca

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Do

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Alte

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Cla

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Pe

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AA

Mo

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2 3 3 3 3 2 2 2 2 2 2 2 2

3 4 4 4 4 3 3 3 3 3 3 3 3

4 5 5 5 5 4 4 4 4 4 4 4 4

Optimized IDT Screening Dilutions

Normal Degree of Clinical Sensitivity

Moderate Degree of Clinical Sensitivity: DROP BACK 1 DILUTION

High Degree of Clinical Sensitivity DROP BACK 2 DILUTIONS


IDT Technique: Advantages of Optimized vs Standard IDT testing

Speeds up testing process Minimizes the number of

skin tests & patient’s discomfort

Minimizes testing expense Allows better workflow so

that more patients can be tested in the same amount of time


Modified Quantitative Testing (MQT) Skin Prick Test (SPT) is first used as a

rapid screening measure of reactivity, then selective IDT testing done based on SPT results

Using the Multi-Test II device is estimated to yield a skin response equivalent to a 1:1500 w/v IDT, this first step is similar to a #3 dilution

Current in vivo and in vitro screens for inhalant allergy. KrouseJH, Stachler RJ, Shah A. Otolaryngology Clinics of North America. 2003 Oct;36(5):855-68.


Multi-Test

Device allows consistent application of multiple tests to screen initial sensitivity

Rapid, with minimum patient discomfort


Modified Quantitative Testing (MQT)

SPT is used in combination with IDT If SPT negative, a single stronger IDT may be

administered If SPT positive, a single weaker IDT may be

administered The combination of SPT with IDT yields an

efficient, rapid estimate of the strength of the allergic response that can be interpreted and used in treatment vial preparation



MQT Algorithm Summary SPT Wheal Size: > 9mm, No ID, Interpret as #6

EP SPT Wheal Size: 3-8 mm, Apply #5 ID

If ≤5mm, Interpret as #4 EP If 7-9mm, Interpret as #5 EP If ≥9mm, Interpret as #6 EP

SPT Wheal Size: <3mm, Apply #2 ID If ≤6mm, Interpret as NEG If ≥ 7mm, Interpret as #3 EP



MQT Algorithm


Testing Technique Summary

Test Efficiency &

Economy

Specificity Sensitivity

SPT only Yes Yes No

IDT No Yes Yes

Optimized IDT

Yes Yes Yes

MQT

(SPT+IDT)

Yes Yes Yes


Special considerations:

Know your pollens


Special considerations Know your regional pollens!



Know your pollens Use of Allergen Mixes in testing


Use of Allergen Mixes: Testing & SLIT Considerations

Testing with allergen mixesReduces the number of testsTakes advantage of cross-reactivity or co-

seasonality

For SLIT Inducement of new sensitivities is not a

concern


Use of Mixes: Testing and SLIT Considerations Easy to describe “mixology”

“Non Cross-reacting Mix”-a combination of non or slightly cross reacting allergens, i.e., ones that pollinate at the same time (Fall Pollen) or are grouped by type (11-Tree Mix, AA Mold Mix).

“Cross-reacting Mix”-a combination of highly cross-reactive major allergens, i.e., Mite Mix (equal parts Dp, Df) Ragweed Mix (short, giant) or Standardized Grass (equal parts antigen K grasses).


Use of Mixes: Testing & SLIT Considerations

Contrary to what is often recommended for SCIT treatment, we liberally use mixes for both testing and treatment

If your practice intends to provide both SCIT and SLIT, then continue to test with single allergens and treat the SLIT patients with mixes, using the highest reacting constituent allergen to determine the treatment level

Stay tuned, more to follow during later presentations!



Know your pollens Use of Allergen Mixes in testing Recognizing atypical responses


IDT: Atypical Skin Test Responses

# 6 # 5 #4 #3 #2 #1

4 4 5

7

21Endpoint

5 7 7

7

Endpoint

9 11



Know your pollens Use of Allergen Mixes in testing Recognizing atypical responses Recognizing & recording delayed

reactions


IDT: Atypical Skin Test Responses (cont.): Late Phase Reactions

7

Endpoint

5 7

Endpoint

7 8

“Delayed”


IDT: Delayed Reactions

Day of Testing 24 hrs later 48 hrs later



Pt. J.S. 2 weeks later


Dr. Keith Eaton LRCP LRCS1936-2002


Moulds, Yeasts, Ascospores, Basidiospores, Algae and Lichens: Toxic and Allergic Reactions “…delayed reactions should be actively

sought in every patient. When this is done it may be noted that moulds in particular may be associated with delayed skin responses, which take various forms.”

Eaton, K . J Nutr Environ Med. 2002;12:321-335



Often occur in mold allergic patients Often occur in patients with chronic sinus

congestion, fatigue, aching, headaches Can be effectively treated with sublingual

immunotherapy The safe treatment dose is the

strongest wheal dilution with no significant delayed reactivity


IDT: Delayed Reaction Report Card



Know your pollens Use of Allergen Mixes in testing Recognizing atypical responses Recognizing & recording delayed

reactions Special testing considerations


IDT: Special Testing Situations

Young child: # tests=age +2 Patient with history of systemic rxn from

prior allergy testing & patients on beta blockers Do std titration with few selected antigens

beginning at very weak dilutions (#’s 5,6,7)

Patient recently on medications potentially influencing skin test response Do histamine control, consider: retesting off

meds, RAST/ELISA test


Skin Testing: Histamine Control

Concentrate 6 mg/ml Dilution #1: .25 cc conc + 4.75 cc coca Will validate results by documenting skin test

reactivity, especially forVery old or very young patientsPatients with recent ingestion of medications

that may suppress skin test response

Usually start with #3 dilution


IDT: Special Testing Situations: Beta Blockers

12 yr survey of fatal reactions to allergen injections and skin testing: 1990-2001-- none receiving beta blockers Bernstein DI, Wanner M et al JACI 113(6):1129-36,

2004. AAOA sponsored study 2003-2008 : safety of allergy

IDT testing and treatment in patients taking beta blocker medication

Dr. Veling, AAOA 33 months, 21,000 tests IDT

8 test reactions, incidence .04%, no deaths


IDT: Special Testing Situations; Beta Blockers: AAAAI Position Paper

“Systemic reactions to skin testing are rare. Nevertheless, special precautions, when appropriate, should be taken when the patient needs sensitivity testing and cannot stop treatment with a beta-blocking agent.”


Causes for INCREASED ID reactions on FOLLOW-UP IDT/MQT testing

Falsely suppressed tests on initial visit due to pre-medication

IAQ issues in home: Increased exposure from indoor allergen contamination (animals, dust, mold) in interim

IAQ issues at worksite: “Sick Building” with increased allergen exposures in interim since seen

High allergen load engendered by recent personal activity immediately preceding f/u testing

Testing of seasonal allergen “in season” on f/u visit, whereas it was tested pre-seasonally on first visit

Recent ingestion of a cross-reacting food allergen


False negative inhalant tests

Localized IgE production can exist! Remember the skin test is a “surrogate

marker” for reaction in other parts of the body

Some patients (allergic conjunctivitis) may have minimal skin test reactivity but still react in the eyes


Skin test “memory”

Remember skin test sites have a “memory” (skin resident memory

t cells) An allergenic exposure may trigger a

reaction at prior skin test sites Most often caused by molds Example: A boy who mows the lawn


Tools of the Allergist Skin Tests

ScratchSkin Prick Test Intradermal (ID, IDT)

In Vitro TestsSpecific IgE

RAST (radioallergosorbent test) ELISA (enzyme-linked immunosorbent assay) Phadia diagnostic component testing

Total IgE, other tests


In Vitro Tests

Types of tests Principles & mechanisms Advantages/disadvantages Indications Scoring Sample panel & hints


Discovery of IgE Kimishige & Teruko Ishizaka,1967


Types of In Vitro Tests

RAST (radioimmunosorbent test) Introduced in 1972With minor exceptions, now obsolete,

“RAST” acronym persists!

ELISA (enzyme-linked immunosorbent assay)Variety of commercial systems in useEach use different technology to bind

IgE to a surface, tag & meas

Assays for total IgE or allergen-specific IgE


ELISA test

In 1980s, more than a dozen commercial test systems existed

Current main methods:TurboRAST (Agilent Tech) Immulite (Siemens Medical) ImmunoCAP (Thermo Fisher)Hycor UltraSensitive EIA

Note: results from different systems are not always comparable to each other, even if provided in the same units


ELISA measures unbound IgE in the allergic Cascade


ELISA Testing: Summary


ELISA Testing: Technique


In Vitro Tests: Advantages

No risk to patient Less time-consuming than skin tests No interference by drugs Quantifiable measure of IgE antibody

which can be followed with treatment Ideal for assessing systemic IgE-

mediated food allergy


In Vitro Tests: Disadvantages Reimbursement restrictions, such as

limitations on number of tests performed Lab-to-lab variability Results not immediately known No information provided on “delayed

reactions” Measures IgE in blood and not a specific

organ “surrogate marker”


In Vitro Tests: Diseases with high yield Atopic Dermatitis Chronic Respiratory/sinus congestion Asthma Recurrent infections Chronic gastrointestinal symptoms Chronic urticaria Anaphylaxis


In Vitro Tests: Indications

Infants, uncooperative patients Patients on antihistamines and other

medications causing skin test suppression

Pts with severe risk of anaphylaxis Pts with extensive skin disease,

dermagraphism


Typical IgE Modified Class System

Neg <0.05 Absent

1/0 0.05-0.08 Equivocal

1 0.08-0.15 Low

2 0.15-0.50 Increasing Levels

3 0.50-2.50

4 2.50-12.50

5 12.50-62.50

6 >62.60

Specific IgE Class Conc in IU/ml Interpretation


In Vitro Test Interpretation: Clinical Considerations (Cont) “After additional analysis, if the ELISA test

results (or skin testing) remain inconsistent with the patient’s clinical history, the overriding criteria in making the final diagnosis should be the clinical history and physical examination…”



Thank you

Next:

Break followed by

La Crosse Method Practice Protocol Dosing Guidelines for Inhalant Allergies

Mary Morris MD


Thank You

george f. kroker, md facaai diagnostic techniques for inhalant/environmental treatment

Documents

allergy associates

allergy skin

skin test reactivityage

skin test charles blackley

blood test results

crosseskin testing

specific slit protocol

serum ige tests