BSACI guideline for the diagnosis and management of cow’s milk allergy

May 12, 2014 4:01 pm

Summary

This guideline advises on the management of patients with cow’s milk allergy. Cow’s milk allergy presents in the first year of life with estimated population prevalence between 2% and 3%. The clinical manifestations of cow’s milk allergy are very variable in type and severity making it the most difficult food allergy to diagnose. A careful age- and disease specific history with relevant allergy tests including detection of milk-specific IgE (by skin prick test or serum assay), diagnostic elimination diet, and oral challenge will aid in diagnosis in most cases. Treatment is advice on cow’s milk avoidance and suitable substitute milks. Cow’s milk allergy often resolves. Reintroduction can be achieved by the graded exposure, either at home or supervised in hospital depending on severity, using a milk ladder. Where cow’s milk allergy persists, novel treatment options may include oral tolerance induction, although most authors do not currently recommend it for routine clinical practice. Cow’s milk allergy must be distinguished from primary lactose intolerance. This guideline was prepared by the Standards of Care Committee (SOCC) of the British Society for Allergy and Clinical Immunology (BSACI) and is intended for clinicians in secondary and tertiary care. The recommendations are evidence based, but where evidence is lacking the panel of experts in the committee reached consensus. Grades of recommendation are shown throughout. The document encompasses epidemiology, natural history, clinical presentations, diagnosis, and treatment.

Executive summary

• Cow’s milk allergy may be defined as a reproducible adverse reaction of an immunological nature induced by cow’s milk protein. (A)

• Cow’s milk allergy can be classified into IgE-mediated immediate-onset and non-IgE-mediated delayed-onset types according to the timing of symptoms and organ involvement. (A)

• The prevalence of cow’s milk allergy is between 1.8% and 7.5% of infants during the first year of life. (B)

• Cow’s milk allergy commonly presents in infancy with most affected children presenting with symptoms by 6 months of age. Onset is rare after 12 months. (B)

• Cow’s milk allergy has a favourable prognosis, as most children will outgrow their allergy by adulthood. (B)

• Cow’s milk allergy is more likely to persist in IgEmediated disease and where there is greater sensitivity (higher specific IgE levels), multiple food allergies and/or concomitant asthma and allergic rhinitis. (B)

• The clinical diagnosis in IgE-mediated disease is made by a combination of typically presenting symptoms, for example urticaria and/or angiooedema with vomiting and/or wheeze, soon after ingestion of cow’s milk and evidence of sensitization (presence of specific IgE). The spectrum of clinical severity ranges from skin symptoms only to life threatening anaphylaxis. Clinical assessment should include a severity evaluation to ensure affected individuals are managed at the appropriate level. (B)

• The clinical diagnosis of non-IgE-mediated disease is suspected by the development of delayed gastrointestinal or cutaneous symptoms that improve or resolve with exclusion and reappear with reintroduction of cow’s milk. As with IgE-mediated disease, non-IgE-mediated disease varies widely in clinical presentation from eczema exacerbations to life threatening shock from gastrointestinal fluid loss secondary to inflammation [food protein-induce enterocolitis syndrome (FPIES)]. (B)

• Gastrointestinal symptoms of non-IgE-mediated cow’s milk allergy are variable and affect the entire gastrointestinal tract. There are some well-recognized more easily identifiable conditions (e.g. eosinophilic proctitis), but symptoms are more commonly nonspecific. Cow’s milk allergy should be considered in these circumstances where symptoms fail to respond to standard therapy or where other features of allergy are present. (B)

• Lactose intolerance can be confused with non-IgEmediated cow’s milk allergy as symptoms overlap. The terms are thus frequently mistakenly used interchangeably. Lactose intolerance should be considered where patients present only with typical gastrointestinal symptoms. (B)

• The reported level of IgE required to support a diagnosis of IgE-mediated cow’s milk allergy varies between studies and depends on the research population. A skin prick test (SPT) weal size ≥ 5 mm (≥ 2 mm in younger infants) is strongly predictive of cow’s milk protein allergy. (C)

• A food challenge may be necessary to confirm the diagnosis in IgE-mediated disease where there is conflict between the history and diagnostic tests. (D)

• Food elimination and reintroduction is recommended for the assessment of non-IgE-mediated cow’s milk allergy where there is diagnostic uncertainty. (C)

• The management of cow’s milk allergy comprises the avoidance of cow’s milk and cow’s milk products and dietary substitution with an allergenically and nutritionally suitable milk alternative. (D)

• The choice of cow’s milk substitute should take into account the age of the child, the severity of the allergy, and the nutritional composition of the substitute. Nutritionally incomplete substitutes can lead to faltering growth and specific nutritional deficiencies. (D)

• As cow’s milk is the major source of calcium in infant diets, children on milk exclusion diets are at risk of a deficient calcium intake. A dietitian should assess calcium intake and dietary or pharmaceutical supplementation advised where appropriate. (D)

• Cow’s milk allergy will resolve in the majority of children. Individuals should be reassessed at 6–12 monthly intervals from 12 months of age to assess for suitability of reintroduction. (B)

• The reintroduction of cow’s milk may be graded according to the ‘milk ladder’ with less allergenic forms offered initially. More allergenic forms are then eaten sequentially as tolerated. Reintroduction can be performed at home or may need to be supervised in hospital. (D)

• Oral tolerance induction offers a novel treatment option to the small but clinically significant proportion of affected individuals whose cow’s milk allergy persists. (C)

• Cow’s milk allergy in adults more commonly arises in adulthood but may persist from childhood. This is frequently a severe form of allergy where up to 25% have experienced anaphylaxis. (C)

Introduction

Cow’s milk protein allergy is most prevalent during infancy and early childhood when milk forms the greatest proportion of an individual’s food intake. This guideline for the management of patients with cow’s milk allergy will focus predominantly on this age group, although it will encompass older children and adults as cow’s milk allergy persists in a small proportion of patients and can present in this group in its severest form. The guideline, which was prepared by an expert group of the Standards of Care Committee (SOCC) of the British Society for Allergy and Clinical Immunology (BSACI) including a lay commentator, addresses the clinical manifestations and management of cow’s milk protein allergy with recommendations for families with milk allergic children. This guidance is intended for use by specialists involved in the investigation and management of individuals with cow’s milk allergy.

Evidence for the recommendations was obtained from literature searches of MEDLINE/PubMed/EMBASE, NICE, and the Cochrane library (from 1946 to the cut-off date, March 2012) using the following strategy and key words – (hypersensitivity OR immune-complex disease OR atopic dermatitis OR eczema OR eczematous skin diseases OR colitis OR irritable bowel syndrome OR exanthema OR enteritis OR rash OR oesophagitis OR allergy OR skin prick test OR anaphylaxis OR contraindications OR IgE mediated adverse reactions) AND (milk OR caseins OR lactalbumin OR lactose OR lactic acid OR dairy). The experts’ knowledge of the literature and hand searches as well as papers suggested by experts consulted during the development stage were also used

[2]. Where evidence was lacking, a consensus was reached amongst the experts on the committee. The strength of the evidence was assessed by at least 2 experts and documented in evidence tables using the grading of recommendations as in a previous BSACI guideline [1], see Box 1. Conflict of interests were recorded by the BSACI. None jeopardized unbiased guideline development. During the development of the guidelines, all BSACI members were consulted using a web-based system and their comments carefully considered by the SOCC.

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