Cow's Milk Protein Allergy Flashcards
Definition cow’s milk protein allergy
A reproducible immune-mediated allergic response to one or more proteins in cow’s milk. Milk contains casein and whey fractions made up of around 20 potentially sensitising proteins which may trigger a reaction
Classification of cow’s milk allergy
Can be classified according to the underlying immune mechanism and timing of symptoms:
* IgE mediated- follows exposure and sensitisation to trigger food allergens with the development of serum-specific IgE antibodies- produces immediate and conistently reproducible symptoms which can effect multiple systems- generally occur 2 hours following ingestion
* Non-IgE mediated- involves a cell-mediated mechanism and reactions are typically delayed. This usually manifests between 2 and 72 hours after ingestion
* Mixed IgE and non-IgE reactions- also typically delayed
Prevalence, most common mechanism and peak age of onset
- One of the most common presentations of food allergy seen in early childhood, second to egg allergy
- Most common presentation is mild-to-moderate non-IgE mediated allergy
- Almost all cases present before one year of age
- Prevalence is between 1.8-7.5% in infants during the first year of life
Prognosis of cow’s milk allergy, what mechanism is more severe
- Generally resolves
- IgE mediated cow’s milk allergy is more likely to persist in children with concomitant atopic conditions, severe symptoms, multiple food allergies, FHx and a large skin prick test
- IgE mediated- 55% tolearnt by age 5
- Non-IgE medaited-tolerant by age 3 (more likely to resolve quickly
- Food challenge is often performed in hospital setting as anaphlaxis can occur
Possible complications of cow’s milk protein allergy
- Stress and anxiety, social exclusion and reduced quality of life
- Restricted diet and malnutrition
- Severe anaphylaxis (rare-but food allergy is most common cause of food allergy in the community)
- Enterocolitis, enteropathy and protoclitis
Presentation of IgE mediated cow’ milk protein allergy
- Typcially rapid onset (within minutes and up to 2 hours after ingestion)
- Skin- pruritis, erythema, acute localised or generalised urticaria, acute angio-oedema (rarely- generally occurs at the lips, face and around the eyes), eczema flare up
- GI- nausea, colicky abdominal pain or discomfort, vomiting, diarrhoea
- Respiratory- lower respiratory cough, chest tightness, wheezing, SOB, sneezing, itching, rinorrhoea
- Rare- systemic symptoms and anaphylaxis
Presentation of non-IgE medaited cow’s milk allergy
- Typically delayed (usually 2-72 hours after ingestion)
- Skin- pruritis, erythema or flushing eczema flare up
- GI- GORD, vomiting, loose or infrequent stools, abdominal pain and discomfort, food refusal, pallor, tiredness, faltering growth
- Respiratory- lower respiratory cough, chest tightness, wheeze, SOB
What factors might indicate a possible diagnosis of cow’s milk allergy
One or more of the following symptoms or multiple persistent, severe, or treatment resistant symptoms (GORD, atopic eczema, constipation)
Investigations for Cow’s milk allergy
- Generally a clinical diagnosis so history and examination is important
- Should examine for signs of clinical reaction, growth and comorbid conditions
- Ask about: The symptoms, severity, frequency, speed of onset, duration, and the timing of the reaction in relation to cow’s milk exposure.
- A food and symptom diary may be helpful
- Symptoms usually develop within 1 week of cow’s milk introduction
- Consider arranging a skin prick test and/or serum specific IgE testing
The trigger is usually cow’s milk, however, it may be cow’s milk protein in maternal breast milk in infants who are exclusively breastfed (rare in IgE mediated)
IgE-mediated reactions usually occur following a small amount of milk, whereas non-IgE-mediated reactions usually occur after ingestion of larger volumes of milk
Differentials for Cow’s milk allergy
- Food intolerance e.g lactose intolerance-will present with abdominal pain, bloating and explosive diarrhoea around 30-60 mins after ingestion
- Other food allergies
- Colic, Crohn’s disease, coeliac disease, constipation, UC, pancreatic insufficiency and cystic fibrosis, infection
Management of mild to moderate IgE mediated cow’s milk allergy
Shoudl arrange immediate ambulance transfer to A&E if there are systemic symptoms or suspected anaphlaxis with or without angio-oedema
- Assess for the presence of IgE using skin prick testing/ serum specific IgE (wherever available)
- Refer to a specialist allergy clinic if history of systemic symptoms, concurrent asthma, atopic eczema, multiple food allergies, or allergy testing is not available in primary care
- Consider referral to a paediatric dietician whilst awaiting specalist assessment
- Advice: Allergy UK, CMPA support, NHS website, food labelling advice, have oral antihistamies at home in case of reintroduction or after food challenge
- Exclusively brest-feeding mother: exclude cow’s milk protein from mothers diet, mother to take calcium and vitamin D supplements
- Formula fed or mixed feeding and unable to return to exclusive breastfeeding, trial of extensively hydrolysed formula (eHF)
- Follow up with specialist allergy service
Management of severe IgE mediated cow’s milk allergy
As for mild-moderate management + consider elemental (amino acid) formula if extensively hydrolysed formula is not effective
Management of mild-moderate non-IgE mediated cow’s milk allergy
- Be wary of diagnosing infant with CMA as GI symptoms of vomiting and diarrhoea are very common
- Consider referral to allergy clinic for same indication as IgE mediated disease
- If referral to an allergy clinic is not required, advise a trial elimination of all cow’s milk from the mother/infants diet for 2-4 weeks
- During trial: In exclusively breastfed babies, actively support continued breastfeeding where possible. Mother to exclude all cow’s milk protein from her die- need dietary supplementation with calcium and vitamin D
- During trial: In formula-fed or mixed-fed infants, actively support continued breastfeeding where possible. If unable to return to exclusive breastfeeding replace cow’s milk-based formula with a hypoallergenic infant formula
- If there is clear improvement in symptoms, arrange home reintroduction of cow’s milk into diet to confirm diagnosis -> no symptoms= incorrect diagnosis, return of symptoms= continue to exclude all cow’s milk from the diet (formula fed- give hypoallergenic formula)
- Advise cow’s milk free diet until the child is 9-12 months old and for at least 6 months if diagnosis is confirmed.
- After exlusion complete, redintroduce using the milk ladder
Management of severe non-IgE mediated cow’s milk allergy
Urgent referral to local paediatric allergy service and dietician
Management of severe non-IgE mediated cow’s milk allergy
Urgent referral to local paediatric allergy service and dietician
