An infant with severe dehydration would be expected to present with which finding?

• A. Bulging fontanelles
• B. Absent urine output
• C. Excessive tearing
• D. Moist oral mucosa

Answer: (B)

Severe dehydration in an infant is best identified by very low urine output because when fluid volume is critically reduced, kidney perfusion falls and urine production drops dramatically. Absent urine output signals this reduced perfusion and is the strongest, most direct clue among the options.

Other signs here don’t fit with severe dehydration. A bulging fontanelle isn’t typical in dehydration; fontanelles tend to be sunken as hydration status worsens. Excessive tearing usually occurs with crying or adequate hydration, not dehydration. Moist oral mucosa indicates the mouth is well hydrated, which argues against dehydration.