Almost everything the GP needs to know about Paediatric Allergy!

Donna TravesPaediatric Consultant Royal Derby Hospital

March 5th 2014

Aims and Objectives

Allergy Testing and the service in Derby Who should be tested and referred Skin Prick Testing Specific IgE testing Adrenaline auto injectors – who and how many? Cows Milk protein Allergy and Intolerance

– The variety of milks!– When and how to change and trial

Feeding issues – GORD

Allergy versus Intolerance

Allergy – rapid, response from immune system, usually IgE mediated but not always.

– Usually within 15-30minutes

Intolerance - the immune system is not involved.– Normally harmless substances cause symptoms, but often the mechanism is not

understood. – Much slower onset after eating, often hours

Allergy for dummies!

Hypersensitivities

Statistics

Severe food allergy – rare 2% of population, 8% < 3years

Anaphylaxis: Incidence 10-50 per 100,00 person-years Lifetime prevalence ~0.005% Fatality of

– 2 per million USA– 0.66 per million Australia– 0.33 per million UK

Food intolerance – more common

Key points in taking a food allergy history

Disease specific historyRange of symptoms of allergy and anaphylaxis

Cutaneous:– Flushing, Pruritis, urticaria, angioedema, sensation of warmth,

Respiratory: – Upper – rhinorrhoea, congestion, sneezing, hoarseness, stridor– Lower – cough, wheeze, dyspnoea, tight chest

Gastroinstenstinal:– Pruritis / oedema of lips/tongue, palate, metallic taste in mouth, nausea,

vomiting, abdominal cramps, diarrhoea CVS:

– Tachycardia, arrhythmia, syncope, hypotension Neuro:

– Sense of impending doom, anxiety, headache, seizure, LOC Ocular:

– Pruritis, conjunctival injection, lacrimation

Disease specific historyTypes of Allergic conditions

IgE mediatedIgE mediated

(acute onset)(acute onset)IgE and cell IgE and cell mediatedmediated

(delayed onset / (delayed onset / chronic)chronic)

Cell mediatedCell mediated

(delayed onset / (delayed onset / chronic)chronic)

Acute urticaria / Acute urticaria / angioedemaangioedema

Contact urticariaContact urticaria

AnaphylaxisAnaphylaxis

Food-associated Food-associated

exercise induced exercise induced anaphylaxisanaphylaxis

Oral allergy syndromeOral allergy syndrome

(pollen-associated food (pollen-associated food allergyallergy

syndrome)syndrome)

Atopic dermatitisAtopic dermatitis

Eosinophilic Eosinophilic oesophagitisoesophagitis

Eosinophilic Eosinophilic gastroenteritisgastroenteritis

Food protein-inducedFood protein-induced

enterocolitis syndromeenterocolitis syndrome

Food protein-inducedFood protein-induced

allergic proctocolitisallergic proctocolitis

Allergic contact Allergic contact dermatitisdermatitis

Allergen specific history…Common allergens to consider

Major food allergens: Tree nuts (almonds, Brazil nuts, cashew nuts and pistachio nuts, hazel nuts,

pecan nuts and walnuts) Milk, eggs, soya and wheat Fin fish and crustacean shellfish (shrimps, crabs, crayfish)

EU food allergy label requirements: 14 food types that need to be labelled on pre-packed foods when used as

ingredients: Peanuts, tree nuts, sesame, milk, eggs, soya, lupin Cereals containing gluten (wheat, rye, barley, oats, spelt, kamut) Fin fish, crustacean and molluscan shellfish Mustard, celery, sulphites

Age at onset of specific conditions

Cross-reactivity among foods

Cross reactivity cont:

Sicherer SH. Clinical implications of cross-reactive food allergens. J Allergy Clin Immunol 2001; 108: 881-890

Who to refer?

NICE recommends that referral to secondary or specialist care be considered in any of the following circumstances. The child or young person has: faltering growth in combination with one or more of the gastrointestinal symptoms described in signs and symptoms of possible food allergynot responded to a single-allergen elimination diethad one or more acute systemic reactionshad one or more severe delayed reactionsconfirmed IgE-mediated food allergy and concurrent asthmasignificant atopic eczema where multiple or cross-reactive food allergies are suspected by the parent or carer.

OR there is: persisting parental suspicion of food allergy despite a lack of supporting historystrong clinical suspicion of IgE-mediated food allergy but allergy test results are negative or the allergen is not easily identifiedclinical suspicion of multiple food allergies.

Who to refer…

All children who present with anaphylaxis Children who have been prescribed an adrenaline auto injector (AAI).

Investigations available

SPT Intra dermal testing Food challenges Specific IgE tests Component resolved diagnostics

SPT

AdvantagesAdvantages DisadvantagesDisadvantages

Easy to performEasy to perform Non-invasiveNon-invasive Immediate resultsImmediate results Cost effectiveCost effective Negative test is highly Negative test is highly

predictive of absence of predictive of absence of allergyallergy

Patient can “see” resultPatient can “see” result

Must stop antihistamines Must stop antihistamines 48 h before testing48 h before testing

Severe eczema or Severe eczema or dermographism may prevent dermographism may prevent useuse

Not all substances availableNot all substances available

Positive and negative controls essential

Allergens placed on forearm (or back) > 2 cm apart

Sterile lancet through allergen solution at 90 to skin

Skin Prick Test

- >3mm wheal = positive result

- Do not include erythema in

measurement

Specific IgE tests

AdvantagesAdvantages DisadvantagesDisadvantages

No need to stop No need to stop antihistaminesantihistamines

Appropriate when Appropriate when standardised skin prick standardised skin prick testing not availabletesting not available

Can be used in patients with Can be used in patients with skin disorders e.g. eczema, skin disorders e.g. eczema, urticariaurticaria

Expensive (£13/test)Expensive (£13/test) InvasiveInvasive Delay in obtaining resultsDelay in obtaining results Extra letter or patient visit Extra letter or patient visit

required for explaining resultsrequired for explaining results *May be misleading if total IgE *May be misleading if total IgE

level is very high*level is very high*

IgE results

00 negative resultnegative result < 0.35 KUA/L < 0.35 KUA/L

11 borderlineborderline 0.35–0.70.35–0.7

22 weak positiveweak positive 0.7–3.500.7–3.50

33 positivepositive 3.50–17.53.50–17.5

44 positivepositive 17.5–5017.5–50

55 positivepositive 50–10050–100

66 strong positivestrong positive >100>100

When to use Specific IgE

Clear history of IgE medicated reaction To clarify/confirm suspected allergen To determine between specific foods/causes

NOT fishing exercise Food panels not useful, nut panel can be If in doubt, refer to clinic….!

Component Resolved Diagnostics

ImmunoCAP Allergen Components enable the measurement of specific antibodies to antigenic components at the molecular level.

Measures more specific proteins giving rise to IgE reactions. Can be informative about likelihood of more severe reaction and the

need/ no need for AAI Same cost as a single specific IgE test

Case study

8 mth old Breast fed from birth First exposure to scrambled egg with toast and butter

– Immediate lip swelling, perioral erythema– Wide spread urticarial rash– Vomited x 2– Lasted 1 hour then settled after antihistamines

PMHx: Intermittent wheeze with colds, mild eczema

Investigations

SPT– Positive – 4m– Negative – 0mm– Cows milk – 1mm– Egg - 8mm– Wheat -0mm

Advice:– Continue with milk and bread– Avoid egg in diet– Reintroduce baked egg first in approx 12 months

Egg Allergy

Very common Often tolerate baked products Lesser cooked egg more reactions Usually outgrow in first 2 years Re-Introduce baked egg first – e.g. cake

Food challenges

Indications– Confirm reactivity– Confirm tolerance – index food; cross-reactive foods

Procedure Type – open/ blinded – single / double - placebo Location – home / hospital - access to emergency Treatments Protocol – graded dose; minimise anxiety Supervision – experienced personnel

Nut allergy

Case 8 yr male Well; mild infantile eczema First known single nut contact Immediate symptoms: Generalised urticaria Nausea and stomach ache Profuse vomiting Rapidly recovered No respiratory symptoms Attends for consultation Currently avoiding all nuts

What Investigations and avoidances to advise? Any other treatment?

Nut Allergy

Peanuts = legumes/ ground “nuts” Brazil, hazel, almond etc = Tree nuts In general, avoid all “nuts”

AAI…..?

Adrenaline autoinjectors

Anapen_Lincoln Medical

JEXT_ALK

EpiPen_MedaOld and New

Prescription of Adrenaline Auto Injectors “AAI”(e.g. JEXT/ Epipen)

Absolute indications: Previous anaphylaxis triggered by food, latex or aeroallergens Exercise-induced anaphylaxis Idiopathic anaphylaxis Co-existing unstable or moderate to severe, persistent asthma and symptoms

of IgE mediated allergy Venom allergy in children with more than cutaneous/mucosal systemic

reactions.

AAI prescription

Relative indications : Possible food allergy and 2 or more of following risk factors:

– Mild-to-moderate allergic reaction to peanut and/or tree nut– Older age > 12yrs– Remote from medical help and previous mild to moderate allergic reaction

to a food, venom, latex or aeroallergens – Mild-to-moderate allergic reaction to very small amounts/ traces– Asthma

How many?

The following patients should always have 2 adrenaline autoinjectors prescribed:– Co-existing unstable or moderate to severe asthma – Lack of rapid access to medical assistance to manage an episode of

anaphylaxis due to geographical or language barriers– Previous near fatal anaphylaxis

Anaphylaxis

Definition: Anaphylaxis is a severe, life-threatening, generalised or systemic

hypersensitivity reaction which is likely when both of the following criteria are met:

Sudden onset and rapid progression of symptoms Life threatening :

– Airway e.g. stridor and/or

– Breathing eg wheeze and/or

– Circulation problems eg shock

Anaphylaxis cont:

Skin and/or mucosal changes (e.g. flushing, urticaria, angioedema) can also occur, but are absent in a significant proportion (20%) of cases.

Skin or mucosal changes alone are not a sign of an anaphylactic reaction.

There can be gastrointestinal symptoms eg vomiting, abdominal pain, incontinence.

Anaphylaxis – the stats

The UK incidence of anaphylactic reactions is increasing with an reported increase between 1990 and 2004 of 700%.

There are approximately 20 anaphylaxis deaths reported each year though this is likely to be a substantial under-estimate.

The risk of a fatal anaphylactic reaction is higher is children with pre-existing asthma.

Nuts ->milk -> fish

Anaphylactic Reaction?Move to Resus

Airway, Breathing, Circulation, Disability, Exposure

Call for help

Position:If mainly an A or B problem: Sit patient up

Position:If mainly C problem:Lie patient flat

Adrenaline use Epipen<6 years – Epipen Junior 150mcg IM>6 years – Epipen 300mcg IM

Action:1. Establish airway2. High flow oxygen3. Iv fluid bolus 20ml/kg4. Chlorphenamine IM/IV<6months 250mcg/kg6mth-6yrs 2.5mg6-12 yrs 5mg>12 yrs 10mg

5. Hydrocortisone IM/IV<6months 25mg

6mth – 6yrs 50mg 6-12yrs 100mg >12 yrs 200mg

Monitoring:Pulse oximetryECGBlood pressure

Mast Cell tryptase (red top)Take blood for Mast cell tryptase unless it is a food related anaphylaxis.

-immediatelyand 1-2 hours later (no more than 4 hours)Patients >16 yrs should have Mast cell tryptase taken regardless of trigger

No-Rpt IM adrenaline every 5 minutes-Contact PICU, consider iv adrenaline infusion

YesMonitor as IP for 6 hoursDC if well, had epipen and BLS training and review by SeniorFU Allergy clinic (CH clin g **)Refer Suze Bricknell for school epipen trainingTTA antihistamines and steroids for 3/7

Improvement?

Allergic reactions

Antihistamines – Piriton, cetirizine – as per BNFc

Salbutamol – 5 – 10 puffs of MDI via spacer, repeat as required in response to treatment

Oral corticosteroids eg prednisolone There is no good evidence to support routine steroid administration in allergic

reactions.

A 3 day course of oral prednisolone can be considered in the following circumstances;

-Acute exacerbation of wheeze in known asthmatics -Ongoing and troublesome urticaria/ angioedema -Ongoing symptoms not responding to regular antihistamines

Discharge advice and follow up

Regular anti histamines for up to 3 days. Seek review if symptoms persist beyond this.

Avoid known allergen. Prophylactic anti histamines if known exposure is unavoidable. Patient information leaflets are available for many allergies including egg, milk

and nut allergies. These contain further sources of information for the parents. Good quality patient information can also be obtained from www.allergyuk.org for other allergies.

Milk allergy/Intolerance

Cow’s milk protein allergyDoes the infant have cow’s protein milk allergy?

Case 1 6 mo male infant Breast fed exclusively Mother’s diet unchanged Mild eczema; now resolved Offered baby rice containing milk powder as weaning food Immediate symptoms after one mouthful Hives over face and chest Forceful vomiting Rapidly recovered Ix: SPT / sIgE positive Rx : Milk free diet, dietician Reintroduce Cows milk after 1 year ( baked first) ?in hospital

Cow’s milk protein allergyDoes the infant have cow’s protein milk allergy?

Case 2 4 mo male infant Breast fed briefly for 2 weeks, now SMA Gold No family history of allergy Always been a difficult feeder

– Cries & arches back when fed– Feeds reluctantly, refuses– Regurgitates into mouth– Breathless after feeds

On anti-reflux treatment = Still symptomatic, Slow weight gain Ix: SPT negative Rx Changed to Nutramigen – all settled, dietician Reintroduce milk after 6 months, at home

Diagnostic Approach and Management of Cow’s-Milk Protein Allergy in Infants and Children: ESPGHAN GI Committee Practical Guidelines. April 2012

History suggestive of CMPI

Exclusion diet of cows milk and if Breast feeding, mother to omit cows milk.

Will need replacement formula (soya only generally >1yr)

Refer to paediatrics for review, confirmation of diagnosis (history, SPT, Food challenge) and review by dietician.

Re-introduce/ evaluate every 6-12 months (after age 1 year).

75% tolerate by age 3yrs, 90% by age 6 yrs.

Intolerant after age 5-6 years, refer back to allergy clinic ?? Desensitisation.

Choosing a formula

Eosinophillic oesophagitis

Symptoms might include– feeding disorders,

– reflux symptoms,

– vomiting,

– dysphagia

– food impaction

Multiple triggers – commonly Milk

GORD - History

Suspect GORD in children with either (but usually both) of the following: Frequent and troublesome regurgitation or vomiting (which may occur up to

2 hours after feeding). Frequent and troublesome crying, irritability, or back-arching during or after

feeding, or feeding or food refusal Many other symptoms

– Respiratory– failure to thrive– Difficulty sleeping– Abnormal posture

GORD

Refer the child to a paediatrician or paediatric gastroenterologist if suspected GORD is accompanied by any of the following:

An uncertain diagnosis, for example because the child has diarrhoea (suggesting cow's milk protein intolerance/allergy) or peri-anal excoriation (suggesting lactose intolerance).

Symptoms or signs of anaemia. Faltering growth (failure to thrive). Dysphagia or frequent choking. Respiratory symptoms or signs (including persistent or recurrent cough,

wheezing, or stridor). Marked feeding difficulties (such as feeding refusal), marked crying or irritability

(particularly after feeding), or marked sleeping problems. Abnormal posturing of the head and trunk after feeding (Sandifer–Sutcliffe

syndrome). Severe neurological impairment, cystic fibrosis, or previous gastro-oesophageal

surgery (for example, for oesophageal atresia or diaphragmatic hernia); these children are at risk of severe GORD.

Neonates who were born pre-term, or infants who have complications of prematurity.

Investigations

Usually none! Good history and examination

Management

Offer reassurance – Symptoms tend to become less frequent and less problematic after

6 months of age.

– By 10–12 months of age, only 5% of infants have regurgitation occurring once or more a day.

In clearly overfed babies, advise restriction of the volume of feeds.

Management

2 week trial of the following, in order! Thickened Feed

– Carobel)– Enfamil AR® and SMA Staydown® pre-thickened infant formulae

Cows Milk elimination diet– If successful refer to paeds– If no change back to previous feed

Gaviscon

Management

NICE guidance states: The following treatments are not recommended for initiation in primary care:

Planned positioning in prone, left-lying, right-lying, or upright positions, or elevating the head of the cot.

Histamine-2 receptor antagonists. Proton pump inhibitors. Metoclopramide or domperidone.

Final thoughts on Allergy

Personal management plans:

All children with known allergies should have a written personal management plan available in order to aid prompt treatment in the event of exposure to the allergen or onset of symptoms.

EMERGENCY TREATMENT PLAN FOR ALLERGIC REACTIONS

FOOD ALLERGY

Child’s name - DOB Address This child is allergic to: Contact with any of the above foods must be avoided. Meals/snacks must not contain any of these foods, take special care in restaurants Check labelling on prepared food, as foods can be hidden in pre-packed meals etc

TREATMENT PLAN Emergency Pack must ALWAYS be carried.

MILD REACTIONS TREATMENT PIRITON (Chlorphenamine)

syrup/ tablets

AGE. DOSE. VOLUME of 2mg/ 5ml

syrup. <2 years 1mg 2.5mls 2-6 years 1-2mg 2.5 – 5mls 6-12 years 2-4mg 5-10mls

Skin/mouth itch. Hives/Rash. Lip/face swelling. Nausea/Vomiting. Hoarse voice.

>12 years 4mg 10mls If using alternative antihistamines, please

refer to manufacturers recommended doses on packaging, and inform school and others responsible for child by letter.

Wheezy/Tight chest. Ventolin inhaler (if available) up to 10 puffs

* Seek medical advice if symptoms worsen despite treatment *

SEVERE REACTIONS TREATMENT Any worsening of mild symptoms

despite treatment Imminent collapse. Floppiness. Pale, loss of colour. Loss of consciousness. Severe abdominal pain/diarrhoea. Severe difficulty breathing/swallowing.

Ask someone to call 999 for an ambulance, saying “EMERGENCY ANAPHYLAXIS (anna-fi-lax-is) WITH COLLAPSE WITH BREATHING DIFFICULTY”

Signature:_______________________ Date:____________________-

EMERGENCY TREATMENT PLAN FOR ALLERGIC REACTIONS

NUT ALLERGY

Child’s name - DOB Address

This child is allergic to nuts, and has been advised to avoid all tree and legume

nuts ie. Peanuts, almonds, hazelnuts, brazil nuts, walnuts. Contact with any of the above nuts should be avoided. Food labels should be carefully checked for any of these nuts and for unrefined

nut oils. Please remember nuts can be hidden in foods or cosmetics as ‘extracts’ or ‘oils’.

TREATMENT PLAN Emergency Pack must ALWAYS be carried.

MILD REACTIONS TREATMENT Piriton (Chlorpheniramine) syrup/ tablets.

AGE. DOSE. VOLUME of 2mg/5ml syrup.

<2 years 1mg 2.5 mls 2-5 years 1-2mg 2.5-5 mls 6-12years 2-4mg 5-10 mls

Skin/mouth itch. Hives/Rash. Lip/ face swelling. Nausea/Vomiting. Hoarse voice.

> 12 years 4mg 10mls If using alternative antihistamines, please

refer to manufacturers recommended doses on packaging, and inform school and others responsible for child by letter.

Wheezy/Tight chest. Ventolin inhaler (if available) up to 10 puffs

* Seek medical advice if symptoms worsen despite treatment *

SEVERE REACTIONS TREATMENT Any worsening of mild symptoms

despite treatment. Imminent collapse. Floppiness. Pale, loss of colour. Loss of consciousness. Abdominal pain/diarrhoea. Severe difficulty breathing/swallowing.

Ask someone to call 999 for an ambulance, saying “EMERGENCY ANAPHYLAXIS (anna-fi-lax-is) WITH COLLAPSE”

Lie child down and administer Adrenaline IM auto – injector (Epipen/ JEXT)

DOSE: < 30kg = 0.15mg > 30kg = 0.3mg) in thigh and hold in place for 10 seconds

Signature:_______________________ Date:____________________-

That’s all

Any Questions?

Places to go for information..

www.allergyuk.org– Advice sheets for families and guidance

www.bsaci.org– Up to date guidelines for management. Treatment plans for patients.

An interesting case…

Case study :SS

Aged 15yrs Hazelnut off grandmas tree,

– immediate difficulty swallowing, – high squeaky voice. – No actual breathing difficulties, rash, nausea or vomits. Settled after 30 min, no

treatment Previously had other nuts – peanuts, almonds, dairy milk whole nut, nutella –

no symptoms Mild asthma – no preventer currently No other pmhx of note, mild hayfever

Investigations

SPT – Hazelnut 7mm– Almond 5mm– Walnut 4mm– Peanut 0mm

Advice – avoid all nuts Rx - Epipen as mild asthma, >12yrs and possible upper airway involvement Food challenge to nutella (very keen to eat!)

Case cont:

Food challenge –Nutella : no reaction When Seen again reaction to apple – oral tingling, nil else

Bloods taken: IgE hazlenut – 40 (grade 4) IgE apple 3.3 ( grade 3) Birch pollen – positive, grade 3 CRD’s – Cor a8 - <0.3 ( LTP protein – heat stable) Cor a1 – 42.6 (PR10 protein, heat unstable)

Diagnosis : Oral allergy syndrome Management – no need for AAI, v unlikely to have systemic reaction

Oral allergy syndrome(pollen-associated food allergy syndrome)

Pruritis and mild oedema to oral cavity uncommonly progressing beyond the mouth (7%) and rarely anaphylaxis (1-2%).

Possibly more common in pollen season

Raw fruits and vegetables; cooked forms tolerated.

Examples of relationships:– Birch (apple, peach, pear)– Ragweed (melons)

Oral allergy syndrome:cross reactivity between foods

Oral allergy syndromeFoods that may cause reactions in individuals with pollen allergy

That really is all!