Table 1.
Clinical manifestations of lactose intolerance and cow’s milk allergy [1,4,5,7,8,12,16,33,41,42,43].
| Signs and Symptoms | LI | CMA |
|---|---|---|
| Nausea and/or vomiting | ± | ± |
| Chronic diarrhea | ++ | ± |
| Bloating or abdominal distention | + | ± |
| Abdominal cramps/pain | + | ± |
| Flatulence | + | ± |
| Borborygmi | + | ± |
| Blood and/or mucus in the stool | − | + |
| Rectal bleeding | − | + |
| Perianal rash and irritation | + | − |
| Failure to thrive or poor weight gain | − | + |
| Skin manifestation (e.g., eczema or urticaria) | − | + |
| Respiratory manifestation (e.g., wheezing or asthma) |
− | + |
| Anaphylaxis | − | + (if IgE-mediated) |
| Family history of atopic disease or food allergy | − | + |
LI, lactose intolerance; CMA, cow’s milk allergy; −: no symptoms visible in patients; ±: symptoms may or may not be visible in patients; +: symptoms visible in patients; ++: symptoms are more frequently visible in patients. Note: Congenital lactose intolerance is rare. Primary lactose intolerance is uncommon among infants, but it is quite prevalent among children. There may be an overlap of gastrointestinal symptoms caused by CMA and LI.