Childhood eczema and food allergy : Dr Amanda - Parkside Hospital

transcript

ATOPIC ECZEMA

and the role of

food allergy

Amanda Woods

Consultant

Dermatologist

Queen Mary’s Hospital

Chelsea and

Westminster Hospital

December 2013

ATOPIC ECZEMA

15-20%

children

in UK are

affected

GENETICS

• Loss of function mutations in gene encoding for filaggrin (2006) predisposes to atopic eczema

• Filaggrins are filament-associated proteins that bind to keratin fibres in epidermal cells

• Important in the barrier function of the outer layer of the epidermis

TREATMENT OF ATOPIC

ECZEMA FIRST LINE TREATMENTS

Triple Therapy Treatment

Emollients

Washing

Topical steroids

Should control more than 95% of cases of eczema

TOPICAL STEROIDS

Under-treatment secondary to

steroid phobia is undoubtedly a common cause of low efficacy

Stepwise approach to treatment

Mild Moderate Severe

Emollients

potency

topical

steroids

Emollients

Moderate

potency topical

corticosteroids

Topical

calcineurin

inhibitors

Bandages

Emollients

Potent topical

corticosteroids

Topical

calcineurin

inhibitors

Bandages

Phototherapy

Systemic

Therapy NICE

FOOD ALLERGIES

• Affects 4-8% children

Affect 4 – 8%

of children

Adverse food reactions

true food allergy non-allergic food hypersensitivity

( Immune mediated ) (food intolerance) ie. Tyramine, lactase deficiency

IgE mediated non-IgE mediated

Johansson et al. Allergy 2001; 56: 813-824

IMMUNE MEDIATED REACTIONS

• Immediate onset (within <1hour) :

IgE mediated - type 1 reactions

• Intermediate onset (1- 24 hours): variable IgE involvement

• Late reactors (1-5 days later):

usually non-IgE mediated - type IV reactions

Immediate onset (within <1hour ):

IgE mediated (type 1)

• Skin: urticaria, angioedema

• GIT: vomiting,cramps,

• CVS: hypotension

• Respiratory: cough, wheeze, stridor, rhinoconjunctivitis and

anaphylaxis

Intermediate onset (1- 24 hours):

variable IgE involvement

• Skin : Atopic eczema, chronic

urticaria, angioedema

• GI: FTT, colic, GOR, bloody diarrhoea, constipation

• Respiratory tract: asthma, adenotonsillar hypertrophy

Late reactors (1-5 days later)

usually non-IgE mediated

•Skin: Atopic eczema

•GIT: vomiting, diarrhoea,

eosinophilic enteropathy

The most common dermatological

feature in allergic reactions to foods in

children with atopic eczema:

• acute, pruritic, erythematous, macular or

morbilliform eruption occurring within minutes of

ingestion.

• The effect of repeated exposure to a food trigger

may cause a worsening of atopic eczema.

EFFECT OF REPEATED

EXPOSURE TO FOOD TRIGGER • 1936 Engman et al

• 2 year old child with atopic dermatitis and wheat allergy

• Child admitted to hospital on wheat elimination diet

• When skin cleared, left leg and left arm were bandaged

• Given two wheat crackers

• Within 2 hours he had intense pruritus

• Next day, typical eczematous lesions except

under the bandages

CONCLUSION Cutaneous reaction to food produced

intense pruritus, scratching and

rubbing leading to:

eczematous skin lesions.

PREVALENCE OF FOOD

ALLERGY IN ATOPIC ECZEMA

(proven by DBPCFC)

30 – 56% children with moderate

or severe eczema have

underlying food allergy

Sampson et al 1985

Roehr et al 2001

• Removal of proven food allergens

can lead to a significant

improvement in the child’s eczema

• Regular follow up is important

• Most children acquire tolerance

WHO SHOULD WE TEST?

• Severe eczema requiring daily topical steroids for control or >20% BSA affected

• Under 2 years of age (especially <12 months)

• Early onset eczema (< 3 months)

Who should we test?

• Infants who are exclusively breast

fed ( 0.5% CMP allergy)

• History of adverse reaction to food

• Presence of other symptoms

associated with food

hypersensitivity eg loose stools,

vomiting, asthma

• Failure to thrive

The Presence of Ig E mediated food Allergy and Poor Weight Gain

in a Series of Children Under Two Years of Age with

Atopic EczemaWoods A. L and Marsden R.A

St. George’s Hospital, SW17 0QT

IntroductionUnderlying Ig E mediated food allergy has been found to be a factor in children with moderate or severe atopic eczema(1). The purpose of this study was to determine the prevalence of IgE mediated food allergy in children less than two years of age with atopic eczema who presented to our Paediatric Dermatology Clinic.

Methods

Twenty-seven children with atopic eczema, under the age of two were studied. Data collected included the weight gain of the children from birth to presentation, nutritional history, total Ig E and specific Ig E measurements and skin prick tests.

Results

ConclusionThis study is limited by its’ size. However, the findings suggest that Ig E mediated food allergy is common in children under two years of age with atopic eczema. Poor weight gain is prevalent in this group of children and Ig E mediated food allergy is seen in the majority of those who are failing to thrive.

This may suggest that poor weight gain is an indicator of underlying food allergy in children under two years of age with atopic eczema.

1. Hill DJ, Hosking CS. Food allergy and atopic dermatitis in infancy; an epidemiologic study Pediatr Allergy Immunol. 2004 15(5):421-7.

Weight Gain in Children

with Atopic Eczema

Poor weight gain Increased weight gain maintained weight centile

IgE mediated food allergy No IgE mediated food allergy

Poor Weight Gain and IgE mediated food allergy

Poor Weight Gain and no IgE mediated food allergy

Poor Weight Gain and IgE

mediated Food Allergy

Percentage of Children with Atopic

Eczema and IgE mediated Food

Allergy

Centile change in weight in children with severe eczema

-21-25

Centile change from birth to presentation Median centile change: -12

Centile change post dietary intervention Median centile change: +10

BrJ Dermatol 2010 vol 163

Supplement 1 pp118-130

IgE mediated food allergy No IgE mediated food allergy

Percentage of Children with Atopic

Eczema and IgE mediated Food Allergy

Weight Gain in Children with Atopic

Eczema

Poor weight gain Increased weight gain maintained weight centile

Poor Weight Gain and IgE mediated Food

Allergy

Poor Weight Gain and IgE mediated food allergy

Poor Weight Gain and no IgE mediated food allergy

Centile change in weight in children with severe eczema

-21-25

Centile change from birth to presentation Median centile change: -12

Centile change post dietary intervention Median centile change: +10

Conclusion

• Ig E mediated food allergy is common

in children under two years of age with

severe atopic eczema.

• Poor weight gain is prevalent in this

group of children

Conclusion

• Ig E mediated food allergy is seen in

the majority of those who are failing to

thrive.

• Poor weight gain could be an indicator

of underlying food allergy in children

under two years of age with atopic

eczema.

WHAT TESTS SHOULD WE DO?

7 MOST COMMON FOOD ALLERGENS IN CHILDREN

• Cow’s milk* 2.5-5%

• Egg * 2.6%

• Peanuts 1.6-1.9%

• Soya* 0.5%

• Wheat* ?

• Fish 0.4%

• Tree nuts 0.2%

* Resolve by age of 5 years

INVESTIGATIONS

• FBC

• Ig E

• Specific IgE to cow’s milk

peanut

Specific IgE (RAST tests)

• Quantitate IgE in serum directed

against specific allergen

• Positive Predictive Value of 90-95%

• Useful when skin prick tests are not

available

SKIN PRICK TESTS Positive if wheal size is > 3mm greater than saline

negative control

Negative Predictive Value of more than 95%

There is no correlation between wheal size and severity of allergic reaction

SKIN PRICK TESTS

Advantages

•Rapid

•Cheap

•Easy to do

•More sensitive than blood tests

•More specific than blood tests

•Parents can see the response

Disadvantages

•Requires experience to

interpret

•Risk of anaphylaxis:

I in 3000

•Limited value in patients

with dermographism and

extensive eczema

•Commercial food

extracts are often labile

MANAGEMENT Type 1 allergic reactions

1. Refer to the Paediatric Allergy

Department and a Paediatric Dietician

2. Prescribe piriton

3.Consider an epipen

4.Bronchodilator if asthmatic or history

of respiratory symptoms

5.Prescribe alternative formula milk in

Cow’s Milk Allergy

FOODS CAUSING

ANAPHYLAXIS

• Peanuts

• Milk

• Egg

• Shellfish

• Fish

• Tree nuts

• Sesame

INDICATIONS FOR AN

EPIPEN 1. Type 1 allergic reactions to food that cause

anaphylaxis if there is a history of the following symptoms:

• Difficulty/noisy breathing

• Swelling of tongue

• Swelling/tightness in throat

• Difficulty talking and/or hoarse voice

• Wheeze or persistent cough

• Loss of consciousness and/or collapse

• Pale and floppy (in young children)

2. Type 1 allergic reactions to food if the patient has asthma

INDICATIONS FOR AN

EPIPEN

EpiPen

• Dose of adrenaline is 0.01 mg/kg body weight

• EpiPen Jr. Auto-Injector 0.15 mg is recommended for children weighing 15 - 30 kg.

• For children weighing more than 30 kg, Adult EpiPen Auto-Injector 0.3 mg (adult formulation) is recommended.

ADMINISTRATION OF EPIPEN

• Inject the delivered dose into the anterolateral aspect of the thigh, through clothing if necessary.

• Count for 10 seconds with EpiPen in-situ

• Massage area of injection

• In the absence of clinical improvement or if deterioration occurs after the initial treatment a second injection may be necessary.

• The repeated injection may be administered after about 5 - 15 minutes.

• Patient should be advised always to seek medical help immediately.

ALTERNATIVE FORMULA MILKS

• Extensively Hydrolysed Formulas- EHF

Nutramigen, Pepti

• Amino Acid Formulas – Neocate LCP,

Neocate Advance

• Soya Formulas – Infasoy, Wysoy

Extensively Hydrolysed Formulas-

EHF – (Nutramigen, Pepti)

for uncomplicated non-IgE mediated cow’s milk

hypersensitivity- mild eczema/

gastro-oesophageal reflux

Amino Acid Formulas – Neocate

For severe cow’s milk protein

hypersensitivity –

Severe eczema

Anaphylaxis

GI symptoms

Failure to thrive

Soya Formulas ( Infasoy, Wysoy)

• Children over 6 months only if EHF

or amino acid formulas not

tolerated

• 30-60% of milk allergic children

are allergic to soya

SUMMARY

Consider food allergy in:

Less than 2 years of age

Severe eczema ( daily steroids )

Even if exclusively breast fed

WHERE SHOULD YOU REFER?

• Type 1 food allergies Paediatric

Allergist and Paediatric Dietician

• Severe eczema requiring potent topical

steroids to body or moderately potent

topical steroids to face Dermatologist

REFERENCES • Sampson H et al Food Hypersensitivity and Atopic Dermatitis: Evaluation of 113 Patients.

Journ Pediatr 1985 107:669-675

• Roehr C C et al Children with Food Allergy Presenting as Atopic Dermatitis Compared with Patients with Food Allergy and Gastro-intestinal Symptoms

• Paediatr Allergy Immunol 2001 Apr; 12(2):112

• David T J The Role of Dietary Restriction in Atopic Dermatitis • Textbook of Paediatric Dermatology by J Harper, A Oranje, and N Prose • Baumer J H Atopic eczema in children, NICE. • Arch Dis Child Educ Pract Ed. 2008 Jun;93(3):93-7 • Cox H E Food Allergy as Seen by an Allergist

• Journ Ped Gastro Nutr Nov 2008; 47 Suppp 2: 545-548

• NICE Food Allergy in Children and Young People February 2011

• Ludman S, Shah N and Fox A T Managing Cow’s Milk Allergy in Children

BMJ 2013; 347

Childhood eczema and food allergy : Dr Amanda - Parkside Hospital

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