Pediatric Nutrition in Practice

196 Heine^

Food allergy needs to be distinguished from
food intolerance, which is a non-immune-medi-
ated adverse reaction to food constituents [2].
Examples of food intolerance include lactose
malabsorption, fructose malabsorption as well
as idiosyncratic reactions to food additives or
naturally occurring vasoactive compounds in
foods. Lactose malabsorption is the most com-
mon food intolerance in non-Caucasian individ-
uals. About 70% of adults worldwide suffer from
lactose intolerance due to a genetically deter-
mined decline in lactase activity (adult-onset
hypolactasia) [5]. In children, food intolerances
may indicate the presence of an underlying gas-
trointestinal condition such as celiac disease or
other enteropathies [6]. Due to considerable

overlap between the symptoms of gastrointesti-

nal food allergy and intolerances, the diagnostic

process can be complex and confusing. For ex-

ample, cow’s milk may cause diarrhea due to

non-IgE-mediated gastrointestinal allergy to

cow’s milk protein, or due to malabsorption of

lactose (lactose intolerance).

Pathophysiology

There are two main types of allergic reactions to

food, differentiated by the timing of onset in rela-

tion to food ingestion ( fig. 1 ). Immediate-onset re-

actions occur within minutes after ingestion. In

these patients, the reaction is mediated by food-

Food hypersensitivity

Food protein allergy Food intolerance

Immune-mediated (T helper 2 lymphocytes) Non-immune-mediated

• Intolerance to ingested
  non-protein food ingredients


• Pharmacological reaction,
  dose dependent

Immediate reactions

(IgE-mediated)

• Onset approximately 30–60
  min after food ingestion


• Signs and symptoms:
  Oral tingling/itch
  Urticaria/angioedema
  Lip swelling
  Vomiting/diarrhea

Delayed reactions

(Non-IgE-mediated or mixed*)

• Onset several hours to days
  after food ingestion


• Atopic eczema*


• Eosinophilic esophagitis*


• Anaphylaxis
  Above plus any:
  Upper airway swelling
  Wheeze/stridor
  Hypotonia/collapse
  Cardiorespiratory arrest


• Signs and symptoms:
  Feeding difficulties (infant)
  Vomiting/GER symptoms
  Persistent diarrhea
  Failure to thrive
  Rectal bleeding


• Food protein-induced
  Enteropathy
  Enterocolitis (FPIES)
  Proctocolitis


• Carbohydrate malabsorption
  e.g. lactose, fructose,
  sorbitol, sucrose


• Fat malabsorption
  e.g. intestinal lymphangi-
  ectasia, cystic fibrosis


• Inborn errors of metabolism
  e.g. hereditary fructose
  intolerance


• Idiosyncratic food reactions
  e.g. vasoactive amines, food
  additives and preservatives

Fig. 1. Classification of adverse reactions to foods. GER = Gastroesophageal reflux; FPIES = food

protein-induced enterocolitis syndrome.

Koletzko B, et al. (eds): Pediatric Nutrition in Practice. World Rev Nutr Diet. Basel, Karger, 2015, vol 113, pp 195–202

DOI: 10.1159/000360340