A broad spectrum of symptoms can be attributed to cow milk allergy. Symptoms are either gastrointestinal (Eg vomiting, diarrhea), dermatological (Eg skin rash, eczema, hives) or respiratory (Eg rhinoconjunctivitis, wheezing, oedema), occurring in 50%, 31% and 19% of patients respectively.

The clinical spectrum extends from acute anaphylactic reactions to such diverse disorders as atopic dermatitis, colic, gastroesophageal reflux disease (GERD), esophagitis, allergic colitis and constipation.

In exclusively breastfed infants with cow milk allergy, severe atopic dermatitis is a predominant symptom.

Infants with cow milk allergy have been divided into subgroups according to the site of clinical reaction as well as on the basis of reaction onset time (Hill et al 1986, Baehler et al 1996):


Some infants (Group I) react to relatively small amounts of cow's milk protein (10-20ml) and develop symptoms of hives, distress, and occasional cough and wheeze, within minutes if ingestion. In the second group, larger amounts of CM (180-200ml) are required to provoke symptoms such as violent vomiting and diarrhea, which appear after several hours. In the third group, infants will initially tolerate normal amounts of CM. Symptoms of slowly evolving eczema, diarrhea and bronchitis develop far more insidiously, sometime after several days.