Puzzler: Lingering dehydration in a toddler on the mend: Is it a cry for help?

Your awaited transfer from a small community hospital has finally arrived at the end of the day: a 14-month-old boy whose primary care pediatrician decided to move him to your tertiary care children's hospital in western Pennsylvania because of persistent poor feeding and a need for intravenous fluids to maintain hydration. You arrive on the floor, quickly eyeball the child, observe that his ABCs are stable, and proceed to look through the small stack of paperwork sent with him from the outlying hospital.

The chart tells you that your patient was well until just over two weeks ago, when, along with the rest of his family, he began to have nasal congestion and fever to the touch. When this progressed to purulent nasal drainage with cough and fever, his parents brought him to the pediatrician's office. At that time, he was still breastfeeding but no longer taking solid foods well.

The pediatrician prescribed a course of amoxicillin for otitis media and sinusitis, but changed the antibiotic to azithromycin five days later when the boy's condition had not improved. While the rest of his family recovered from their illness, his activity level remained decreased. Even after his nasal symptoms and fever abated, oral intake remained poor and the cough became worse. This prompted a visit to the emergency department of the community hospital one week ago.

The chart shows that your patient did not improve as an inpatient, despite three days of IV hydration. He was even treated briefly with an antibiotic, in response to a positive throat culture for group A Streptococcus, with no change in his condition.

You establish essentially the same history from the parents. A review of systems reveals the child has lost one pound in the past week. He has not had a fever, or vomiting or diarrhea, in the approximately two weeks since the upper respiratory infection resolved. In fact, he has not passed a stool in the past week! His mother reports that he choked and gagged when feeding was attempted during his stay at the community hospital. These symptoms triggered ENT and GI consultations because of concern about an esophageal foreign body; he underwent upper-tract endoscopy and a head and neck computed tomographic scan. When the results of those studies returned negative, the hospital referred the boy to your institution.

Fluid status alone isn't an explanation A differential diagnosis begins to assemble itself in your mind as you gather information. Clearly, this is not a simple case of dehydration. Infection leads your list, but lab test results from the community hospital showed little evidence of inflammation, you recall. The CBC and urinalysis were normal and, apart from the initial upper respiratory illness, the patient has been afebrile. A chest radiograph was negative as well.

Perhaps this is an electrolyte disturbance, such as hyponatremia? But you remember that electrolyte and renal function tests were normal-on multiple occasions.

You push further into the history, with little to show for it. The boy's medical history and birth history are unremarkable. He met developmental milestones appropriately and has been immunized on schedule. He is breastfed occasionally and partakes of table foods, juice, and water. He lives with his parents and two older brothers; no pets, no smokers in the house. He has no history of exposure to toxins, and household water is from the municipal supply. One of his brothers has psoriasis.

You observe the child while gathering the history. He appears tired and is somewhat fussy. His weak cry ceases when his mother consoles him. The nurse has already collected vital signs: temperature, 37.1° C; pulse, 126/min; respirations, 30/min; and blood pressure, 117/61 mm Hg.