Respiratory Syncytial Virus (RSV) is a common respiratory pathogen that infects nearly all children by age two, though it affects people of any age. While often presenting as a mild cold in older children and adults, it can cause severe illness in infants and high-risk groups. A frequent symptom of RSV infection is a decreased desire to eat or drink. Understanding why this occurs and how to manage the associated risks is important for caregivers.
The Mechanism Behind Decreased Appetite
The body’s physiological response to the viral infection reduces hunger cues. When RSV is present, the immune system releases cytokines, proteins that regulate inflammation. These inflammatory cytokines directly affect the hypothalamus, the brain area controlling appetite, suppressing the desire to eat.
Physical discomfort from respiratory symptoms is another significant contributor. Nasal congestion and excess mucus make breathing difficult, especially for infants who are obligate nose-breathers. Since breathing takes precedence over swallowing, coordinating sucking, swallowing, and breathing becomes exhausting, resulting in poor feeding and refusal to eat.
The general feeling of sickness, or malaise, further reduces interest in food and fluids. Systemic fatigue, combined with a fever, diverts the body’s energy toward fighting the infection rather than processing food. Furthermore, a sore throat can accompany the infection, making swallowing painful and causing a child to avoid intake. The overall effect is a noticeable lack of interest in mealtime.
Identifying and Preventing Dehydration
The primary hazard associated with reduced fluid intake is dehydration, which can develop quickly in infants and young children with RSV. Infants are particularly vulnerable because they have a high body surface area relative to their weight, which increases the rate of fluid loss. The increased respiratory rate and fever accompanying RSV also contribute to faster fluid loss through respiration and perspiration.
Caregivers must watch for specific physical signs indicating insufficient fluid. A clear indicator is a significant reduction in urination; an infant producing fewer than one wet diaper every eight hours shows dehydration. Other signs include a dry or sticky mouth, a lack of tears when crying, or sunken eyes.
For very young babies, the fontanelle (soft spot on the top of the head) may appear sunken. An infant or child who is unusually lethargic, difficult to rouse, or excessively fussy may also be dehydrated. Prompt recognition of these signs is important, as untreated dehydration can quickly escalate into a serious medical concern.
Supporting Intake and Recognizing Severe Symptoms
When a child is sick with RSV, the focus should shift from caloric intake to maintaining hydration. Offering small, frequent amounts of clear fluids or electrolyte solutions is more effective than attempting full meals. The goal is to consistently replace fluids lost due to fever and rapid breathing, even if the child only tolerates a few milliliters at a time.
Before attempting a feeding, particularly for infants, clearing the nasal passages can significantly improve the child’s ability to eat. Using saline nasal drops followed by a gentle suction device temporarily relieves congestion, making it easier to coordinate breathing and swallowing. If the child refuses most solids, prioritizing liquids, such as breast milk, formula, or oral rehydration solutions, is the best approach to prevent a fluid deficit.
Caregivers must be aware of severe symptoms requiring immediate medical attention. Signs of severe respiratory distress include fast, shallow breathing, or retractions (where the skin pulls in between or below the ribs with each breath). Persistent vomiting, an inability to keep any fluids down, or signs of poor oxygenation (such as a blue or gray tint to the lips or fingernails) are urgent warning signs. If a child refuses all fluids or appears significantly less active or alert, professional evaluation is necessary.