Vomiting, failure to thrive in a breastfed infant

Key Points

THE CASE

It's already been a busy day in the office. You see that your next patient is an 8-month-old brought by his parents to see you because of vomiting. You have been following this infant since birth. His birth weight and height were at the 50th and 25th percentiles, respectively. His weight and height today are below the 3rd percentile.

According to your records, deceleration of weight velocity began when the baby was approximately 4 months old. He has been essentially exclusively breastfed because his parents have had difficulty introducing other foods. His parents report that he has always had frequent vomiting, which they describe as "projectile." They also note that it typically contains minimally digested food and occurs moments after ingestion of liquids or solids. There is no blood or bile noted in the emesis.

His development thus far has been normal. Today he is able to sit alone, pull to standing position, and crawl. His past medical history includes full-term vaginal delivery without complication. He has had no surgeries, is on no medications, and has no known drug allergies. Family history is significant for his father having had pyloric stenosis as an infant. The baby's physical exam with the exception of abnormal growth measurements is normal.

You decide that with the significant family history of pyloric stenosis that an ultrasound should be performed, although this diagnosis in a child this age would be unlikely. The ultrasound is normal. The child looks well today, so you decide to initiate lansoprazole (proton-pump inhibitor) therapy at 1 mg/kg per day, thinking that esophageal reflux is the most likely diagnosis. You have advised more intensive feeding therapy to initiate solid foods and have asked the family to return in 6 to 8 weeks.

Three months later

The patient returns to your clinic when he is 11 months old. His parents report that the medication seemed to cause significant gagging, and they discontinued it on their own soon after their last visit. Since then, their son has continued to refuse most solid foods in spite of intensive occupational and feeding therapy.

The vomiting has worsened, and his mom feels that he is vomiting "everything he eats." He is asking to breastfeed nonstop because he is constantly hungry. He has regressed developmentally since you last evaluated him. Today, he can no longer sit alone. He can pull to stand with assistance and continues to crawl. He does not say any words, and although he used to babble, he now makes only a few sounds.

His physical exam reveals weight and height below the 3rd percentile. He has gained just 300 g in 3 months. He has minimal subcutaneous fat. No laboratory workup has been completed. You refer him to a pediatric gastroenterologist who is able to see him quickly and orders an upper endoscopy to evaluate the vomiting. He is scheduled for this within the week, but his parents are unable to keep the appointment.

He returns a month later for the endoscopy. Before the procedure, his parents report that since their clinic visit a month ago, his symptoms have worsened. Specifically, he has increased vomiting, weight loss, and pallor, and he seems less interactive. He has regressed developmentally over the past several months, but the decline in speech and motor skills are even more noticeable over the past month.

The upper endoscopy appears grossly normal, but he is admitted to the hospital secondary to weight loss and significant pallor. On admission, his physical exam reveals tachycardia, with a heart rate of 163 beats per minute, and marked skin pallor. The rest of his vital signs are normal. The patient is somnolent during this initial exam because of the anesthesia he received just hours earlier. The abdominal exam is normal.

Initial laboratory studies on admission include a complete blood count (CBC), complete metabolic panel, urinalysis, and celiac panel.

The initial CBC returns with a white blood cell (WBC) count of 3.8 × 10³ cells/μL; hemoglobin, 5.7 g/dL; hematocrit, 16.9%; platelets, 72 × 10³/μL. Differential includes 13.2% neutrophils, 78.5% lymphocytes, 1.9% monocytes, 0.5% eosinophils, and 3.7% young cells. Mean corpuscular volume (MCV) is 100.4 fL; mean corpuscular hemoglobin (MCH) is 34 pg. The metabolic panel and urinalysis are within normal limits except for total protein, which was slightly low at 5.5 g/dL.