A 5-month-old boy is brought to the physician because of fever and a cough for 3 days. His mother reports that he has had multiple episodes of loose stools over the past 3 months. He has been treated for otitis media 4 times and bronchiolitis 3 times during the past 3 months. He was born at 37 weeks' gestation and the neonatal period was uncomplicated. He is at the 10th percentile for height and 3rd percentile for weight. His temperature is 38.3°C (100.9°F), pulse is 126/min, and respirations are 35/min. Examination shows an erythematous scaly rash over the trunk and extremities. There are white patches on the tongue and buccal mucosa that bleed when scraped.Auscultation of the lungs shows expiratory wheezing. Cardiac examination is within normal limits. Laboratory results are as follows: Serum protein electrophoresis shows a very low gamma globulin level. Chest x-ray reveals an absent thymic shadow. Which of the following is the most likely diagnosis?

Question

A 5-month-old boy is brought to the physician because of fever and a cough for 3 days. His mother reports that he has had multiple episodes of loose stools over the past 3 months. He has been treated for otitis media 4 times and bronchiolitis 3 times during the past 3 months. He was born at 37 weeks' gestation and the neonatal period was uncomplicated. He is at the 10th percentile for height and 3rd percentile for weight. His temperature is 38.3°C (100.9°F), pulse is 126/min, and respirations are 35/min. Examination shows an erythematous scaly rash over the trunk and extremities. There are white patches on the tongue and buccal mucosa that bleed when scraped.Auscultation of the lungs shows expiratory wheezing.  Cardiac examination is within normal limits.  Laboratory results are as follows:  Serum protein electrophoresis shows a very low gamma globulin level.  Chest x-ray reveals an absent thymic shadow.  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

Eductional Objective: Severe combined immune deficiency is characterized by combined T and B cell dysfunction.  It is a life-threatening condition that presents in infancy with severe bacterial and viral infections; mucocutaneous candidiasis; persistent diarrhea; and failure to thrive.  Laboratory findings include absent T cells and hypogammaglobulinemia.  The thymic shadow is not usually present due to severe T cell deficiency.

A 5-Month-Old Boy Is Brought to the Physician Because of Fever