An immunocompetent infant with cow's milk allergy and cytomegalovirus colitis

A 5-week-old, severely ill, infant is described with diarrhoea and rectal bleeding, followed by vomiting and dehydration after introduction of a cow's milk formula. A diagnosis of cow's milk allergy was made because of the clinical presentation of an allergic enterocolitis, the rapid improvement after introduction of a hypo-allergenic formula and development of colic directly after rechallenge with cow's milk. Furthermore a highly specific IgE for alpha-lactalbumin strongly supported the diagnosis. Because of recurrent rectal bleeding a limited colonoscopy was performed at the age of 10 weeks. Surprisingly a second diagnosis of histopathologically proven cytomegalovirus (CMV) colitis was made. Extensive immunological screening revealed no signs of immunodeficiency. The child thrived without any treatment for CMV and developed normally. This is the first description of an immunocompetent infant with CMV colitis. Conclusion: It cannot be excluded that the allergic colitis facilitated the CMV colitis, or vice versa CMV colitis triggered cow's milk protein induced entero-colitis. Further attention should be given to children with bloody diarrhoea to establish a possible relationship between CMV infection and cow's milk protein allergy.