CHILDHOOD ALLERGIESallergy : hypersensitivity reaction initiated by immunologic mechanisms

,

mostly IGE

atopy : genetic predisposition to become sensitised da produce IGEantibodies on exposure to allergens

Allergic March

Infancy : eczema { Early school : rhinitis G asthma

food allergy conjunctivitis

Food Allergy 4 Intolerance

Food hypersensitivity

Food allergy Non . allergic food

I immunological ) hypersensitivity- toxic

, pharmacologicalIGE - mediated ( bacterial poisoning )

- urticarig - angioedema -

non - toxic,

intolerance- anaphylaxis 1 lactase deficiency )

- oral allergy syndrome- atopic dermatitis g

usually delayed onset

- asthma,

rhinitis

Non - IGE mediated

> Clinical Course - protein induced enterolprocto colitis

- early phase - coeliac disease- within mins - dermatitis herpetiformis- release histamine

- urticariq Causes-

angioedema - genetics-

sneezing- environment ( pollution )

- vomiting - diet G lifestyle- bronchospasm - hygiene hypothesis

- late phase - 1989 Strachan

- 4.6 hrs - environment too clean- nasal congestion → lack of exposure

- cough → immature immune system- bronchospasm → 4'

susceptibility

Food allergy is most commonly primary 4 children react on first

exposure .

Infants : milk, egg , peanuts

80 - 90% outgrow by 5 years

Older : peanut ,tree nut

,

fish,

shellfish

Can also be secondary due to cross - reactivity between proteins found

in fresh fruits 1 vegetable 1 nuts 4 in pollens . Generally leads to

mild allergic reactions eg . itchy mouth.

Diagnosis- History 4 exam

- skin tests assess sensitisation to specific- blood tests allergens .

Doesn't mean clinical

- serum specific 1g :L allergy .

- high sensitivity- challenges

- gold standard

Management- individualised- education

- avoidance of allergen- pharmacological

. antihistamines- adrenaline

- specific immunotherapy- prevention

Eczema: atopic dermatitis

Filaggrin gene mutations are a key genetic risk factor due to

impairment of skin barrier function,

which then leads to

cutaneous sensitisation to inhalant G food allergens ,Onset is

usual'

y in first year of life.

- diagnosis is maid clinically- infants

- face

- extensor surfaces

- older

- flexural areas

- friction surfaces- management

- trigger avoidance

emollients

2 corticosteroids- control infection

urticqria 4 Angioedema- Presents as

hivesor redness

-

Results From local vaso dilation 4 4' permeability of capillaries {

venules

- Classificationusually none

- acute : resolves in 6 weeksallergic

commonly due to infection,

Food G drug allergy /- chronic idiopathic : intermittent For at least 6 weeks

- physical : cold, delayed pressure ,

heat,

solar 4 vibratory- Management

2nd gen antihistamines

Insect Sting ( Hymenoptera venom )

severity- mild : local swelling unlikely to develop severe

- moderate : generalised urticgriq-

severe : systemic with wheeze or shock

epipen+ immunotherapy

Rhino conjunctivitisMay be seasonal or perennial

- 20.1.

of children- presentation

-

coryza- conjunctivitis- cough - variant rhinitis

- due to postnasal drip- chronically blocked nose

- management2nd gen antihistamines

t nasal or eye corticosteroids

+ nasal decongestants

ANAPHYLAXISdef : serious allergic reaction with bronchial

, laryngeal or cardio

involvement that is rapid in onset 4 may cause death .

In children,

851.

is due to Food allergy .

Mechanism

- allergic- IGE : food

,venom

,medications

- non . IGE : medications

- non - immunological direct mast cell activation- opioids

- cold,

heat,

exercise

- ethanol

- idiopathic- donal mast cell disorder

Clinical Features- siin got . urticaria

, angioedema- respiratory 10.1

. acute obstruction, bronchospasm

- 91 45.1. cramping ,

diarrhoea- Cvs 45 't

- CNS 15.1 .

Temporal Pattern

uniphasic : resolves in a few hours

biphasic : symptoms recur up to 8 hours later ( 201.)

protracted : associated with profound hypotension

Diagnostic Criteria WHO Guidelines 2011.

sudden onset with skin,

mucosal tissue or both involvement

t one of

sudden respiratory signs2 sudden reduced BP or end - organ dysfunction

OR 2 two of the following after exposure

sudden onset with skin,

mucosal symptoms2 sudden respiratory signs3 sudden reduced BP or end - organ dysfunction4 sudden 91 symptoms

or 3 I BP after exposure to known allergen

Management under 16 years should be

admitted { monitored.

remove triggerABCDE

, repeat every15 mins

in adrenaline I : 1000as needed

Max 0.3mg in children

place supine G raise legs

- high flow 02

- lv fluids : saline rapidly- Monitor 02

,ECG

,BP

- nebulised salbutamol- antihistamine

- bolus methyl prednisolone

Treatment of Refractory- intubation - antihistamines ( cutaneous symptoms )- lv vasopressors - SABA nebulised ( wheeze )

. adrenaline - adrenaline neblstridor )

. offer epipen- educate trigger avoidance

- referral to allergy service