Pneumocystis carinii, cytomegalovirus, and severe transient immunodeficiency.

Pneumocystis carinii infection is rare in infants, and raises strong concerns of immune deficiency. This report describes the unusual case of a male infant with concurrent chest infections caused by P carinii and cytomegalovirus. Investigation was complicated by the strong suspicion of non-accidental injury, including subdural haematomas. The case illustrates how to investigate for possible immunodeficiency. Low immune function tests at presentation slowly improved and have remained normal on longterm follow up. Possible explanations for the transient severe clinical immunodeficiency in this case are discussed.