Navigating Food Reactivity During Illness Season: When Symptoms Blur and Trials Should Wait

Cold season hits differently when your baby already has food reactivity. One day you're confidently tracking symptoms and managing elimination diets, the next you're staring at concerning diapers while your little one runs a fever and refuses to eat. Is this a food reaction, or just another virus making the rounds at daycare?

If you've found yourself second guessing every symptom during illness season, you're not alone. The overlap between viral infections and food reactivity symptoms can turn even the most diligent tracking into guesswork. Understanding how to navigate this challenging period while maintaining your elimination diet progress takes both knowledge and patience.

Why Illness and Food Reactivity Look So Similar

The frustrating truth is that viral gastroenteritis or other illnesses and food reactivity can produce remarkably similar symptoms in infants. Both conditions can cause changes in stool consistency, increased bowel movements, mucus in stools, fussiness, rashes, and feeding difficulties [1]. This overlap creates a diagnostic challenge that even experienced pediatricians find tricky to navigate.

When your baby develops gastroenteritis, the viral infection inflames the intestinal lining and damages the cells that normally absorb nutrients and water. Viral infections damage small bowel cells and cause watery diarrhea without blood, though the inflammation process can sometimes produce mucus [2]. These same symptoms appear in babies with food protein-induced allergic proctocolitis and other non-IgE mediated reactions.

The key distinction often lies in timing and presentation patterns. Viral gastroenteritis typically comes with more dramatic symptoms over a shorter timeline. Children with bacterial gastroenteritis are more likely to have high fever and may have blood and white blood cells in the stool [2]. However, food reactivity can also cause low-grade fevers in some babies, making this distinction less clear-cut than we'd like.

The Critical Rule: No New Trials During Illness

Here's the most important guidance for illness season: postpone any planned food reintroduction trials until your child is fully recovered. This rule isn't just about convenience, it's about getting accurate information that will guide your feeding decisions for months to come.

When your baby's immune system is actively fighting an infection, their gut is already inflamed and compromised. Introducing a new food during this vulnerable window creates an impossible situation. If symptoms appear or worsen, you won't know whether you're seeing a true food reaction or simply the continued effects of illness [3].

The healing timeline matters here too. Resolution of symptoms from food protein-induced allergic proctocolitis typically begins 48 hours after trigger removal and continues steadily, with complete healing taking days to several weeks depending on severity [1]. Viral gastroenteritis follows a similar timeframe, with most cases resolving within one to two weeks [4]. When these timelines overlap, interpretation becomes nearly impossible.

Wait until your baby has been symptom-free and back to their normal eating and sleeping patterns for at least one full week before attempting any food trials. This waiting period allows the gut lining to heal and the immune system to return to baseline, giving you the cleanest possible read on how your baby responds to the new food.

Distinguishing Illness from Food Reactivity: Practical Guidance

While complete certainty isn't always possible, certain patterns can help you make sense of confusing symptoms and know when medical attention is needed.

Viral gastroenteritis typically presents with:

• Sudden onset of symptoms, often with vomiting that precedes or accompanies diarrhea

• Illness affecting multiple family members or coinciding with known exposures at childcare

• Acute phase that peaks within 24 to 48 hours, then gradually improves

• Resolution within one to two weeks [4]

  
  

Food reactivity symptoms typically show:

• More gradual timeline tied to dietary exposures

• Reactions occurring six to 48 hours after ingestion of trigger foods

• Steady improvement once trigger foods are removed [1]

• More chronic and consistent presentation rather than acute, dramatic onset

  
  

Review your food logs carefully. If symptoms appeared shortly after a known dietary change or exposure, food reactivity remains a strong possibility. If symptoms coincided with illness in other household members or known viral outbreaks, infection is more likely.

Seek prompt medical attention if your baby shows:

• Signs of dehydration (decreased urine output, no tears when crying, sunken eyes, unusual lethargy)

• High fever, particularly in infants under three months

• Bloody stools during illness [2]

• Gastrointestinal symptoms persisting beyond two weeks

  
  

If symptoms persist beyond the expected viral timeline, consultation with your pediatrician helps determine whether you're dealing with prolonged viral effects, a separate food reactivity issue, or another underlying condition. This assessment should happen in partnership with your healthcare team rather than through independent dietary experimentation.

Managing Your Elimination Diet While Caring for a Sick Baby

Maintaining your own nutrition during your child's illness presents its own challenges. Between disrupted sleep, constant caregiving, and the general stress of a sick baby, meal planning often falls to the bottom of the priority list. Yet this is precisely when your body needs adequate nutrition to support both your own immune function and continued milk production if breastfeeding.

Focus on simple, nourishing meals that don't require extensive preparation. Batch cooking when possible, accepting help from others who offer to bring food, and keeping easy-to-grab snacks readily available can help you maintain energy levels during the demanding work of caring for an ill child.

Simple supportive measures for both parent and baby:

For congestion and respiratory comfort, warm steam from a humidifier or sitting in a steamy bathroom can help loosen congestion naturally. Nasal saline sprays provide gentle relief for stuffy noses and are safe for even young infants.

Maintaining hydration becomes critical during illness, especially if your baby is experiencing vomiting or diarrhea. For breastfeeding parents, staying well-hydrated yourself supports continued milk production. Coconut water offers natural electrolytes, or you can make a simple homemade electrolyte solution with sea salt and safe juice. For older infants and toddlers who can tolerate additional fluids, several allergen-friendly electrolyte brands exist, including Re-Lyte, LMNT, and Just Ingredients. Always check ingredient labels carefully against your specific elimination needs, as formulations can change.

For breastfeeding parents managing their own illness symptoms, warm broths made from safe ingredients provide both comfort and nutrition. Herbal teas like chamomile or nettle can offer gentle relief (always verify these are safe during breastfeeding for your situation). Seeds like flax, tahini, and chia provides easy calories and healthy fats when appetite is low. Turmeric added to safe foods offers anti-inflammatory properties that may support recovery. For parents experiencing sore throats, salt water gargles provide relief without introducing allergen concerns.

Safe Medications During Elimination

When your baby falls ill, knowing which medications are safe within your elimination framework provides both relief and peace of mind.

For Breastfeeding Parents

Both acetaminophen and ibuprofen are considered safe options for symptom relief. Research shows that these medications pass into breast milk in only very small amounts, far less than typical infant doses, with adverse effects in breastfed infants appearing extremely rare [5][6]. Acetaminophen and ibuprofen are the preferred pain and fever management options during lactation due to their well-established safety profile [7].

However, be cautious with cold medications. While most over-the-counter options are considered safe for short-term use during breastfeeding, first-generation antihistamines like diphenhydramine can cause sedation in infants and may decrease milk supply [5]. Second-generation antihistamines such as cetirizine and loratadine represent safer alternatives when allergy symptoms require treatment.

Remember that honey remains off-limits for infants under 12 months due to botulism risk, but breastfeeding parents can use honey for their own throat comfort without affecting their baby through breast milk [9].

For Infants

Always consult your pediatrician before administering any medications to your baby. Age-appropriate doses of acetaminophen or ibuprofen can help manage fever and discomfort in babies over six months. For younger infants, medication decisions should always involve your healthcare provider.

Avoid giving honey to any baby under 12 months of age. Honey can contain spores of Clostridium botulinum bacteria, which can cause infant botulism, a serious and potentially fatal condition [8]. This restriction applies even to small amounts in baked goods or used to soothe coughs.

Reliable Resources for Medication Safety

When questions arise about specific medications or supplements during breastfeeding, two excellent evidence-based resources can help:

LactMed (Drugs and Lactation Database): A free, peer-reviewed database from the National Institutes of Health providing detailed information about medications and breastfeeding. Access it at https://www.ncbi.nlm.nih.gov/books/NBK501922/

InfantRisk Center: Offers a call center (806-352-2519) where you can speak with experts about medication safety during breastfeeding and pregnancy. They also provide the MommyMeds app for quick reference. Learn more at https://www.infantrisk.com

These resources help you make informed decisions about medications and supplements without adding unnecessary restrictions or taking avoidable risks.

Protecting Your Progress Through Illness

The work you've done to identify and eliminate trigger foods doesn't disappear during illness, but it may feel that way when symptoms return or worsen. Remember that temporary setbacks during viral infections don't negate the progress made through your elimination diet.

Keep maintaining your dietary restrictions throughout your child's illness. Even though new symptoms have appeared, continuing to avoid known triggers prevents compounding the gut inflammation your baby is already experiencing from infection. This consistency gives their system the best chance at efficient recovery once the illness resolves.

Document symptoms carefully, but resist the urge to make dramatic dietary changes based on illness-related symptoms. Note the timeline of symptom onset relative to any illness exposure, track temperature readings, and record the nature and progression of gastrointestinal symptoms. This information helps distinguish patterns once your child recovers and proves valuable if symptoms persist beyond the expected viral timeline.

Moving Forward: Resuming Trials After Illness

Once your baby has fully recovered and maintained normal symptom patterns for at least one week, you can thoughtfully resume food reintroduction trials. This waiting period ensures that any reactions you observe reflect true food responses rather than lingering effects of illness or a still-recovering gut.

When you do restart trials, begin with foods you feel most confident about rather than those you suspect might be problematic. This approach helps rebuild your confidence in the trial process and reduces anxiety after the uncertainty of illness. Document your trials with the same careful attention to detail you used before the illness, noting timing, amounts, and any symptoms that appear.

The Free to Feed App provides comprehensive tracking tools specifically designed for managing food trials, with features for logging maternal and infant intake, documenting symptoms, uploading photos, and tracking trial progressions. This systematic approach removes guesswork and creates a clear record you can share with healthcare providers if questions arise.

You're Equipped for This Challenge

Illness season tests the resilience of every family managing food reactivity. The additional uncertainty can feel overwhelming, but you already have the core skills needed to navigate this challenging time. Your understanding of your baby's baseline symptoms, your commitment to careful tracking, and your willingness to pause and reassess when needed are exactly the tools required.

Maintain your dietary restrictions, postpone trials during active illness, focus on supporting your baby's recovery and your own nutrition, and trust that this temporary disruption doesn't erase the progress you've made. Clear patterns will emerge again once health is restored.

For families looking to simplify meal planning during the demanding stretches of illness season, the Free to Feed Cookbook offers over 50 allergen-friendly recipes designed specifically for elimination diets, helping you maintain energy and wellbeing when you need it most. Schedule a personalized consultation with a Free to Feed Food Allergy Expert for additional support in navigating the complex overlap between illness and food reactivity.

References

[1] Nowak-Węgrzyn, Anna. "Food Protein-Induced Enterocolitis Syndrome and Allergic Proctocolitis." Allergy and Asthma Proceedings, vol. 36, no. 3, 2015, pp. 172-184.

[2] Elliott, Elizabeth Jane. "Acute Gastroenteritis in Children." BMJ, vol. 334, no. 7583, 2007, pp. 35-40.

[3] Mennini, Maurizio, et al. "Food Protein-Induced Allergic Proctocolitis in Infants: Literature Review and Proposal of a Management Protocol." World Allergy Organization Journal, vol. 13, no. 10, 2020, p. 100471.

[4] Riddle, Mark S., et al. "Viral Gastroenteritis." StatPearls, StatPearls Publishing, 2025.

[5] "Acetaminophen." Drugs and Lactation Database (LactMed), National Institute of Child Health and Human Development, 2025.

[6] "Ibuprofen." Drugs and Lactation Database (LactMed), National Institute of Child Health and Human Development, 2025.

[7] Spencer, Jeanne P., et al. "Medication Safety in Breastfeeding." American Family Physician, vol. 106, no. 6, 2022, pp. 638-644.

[8] Abdulla, Chinar O., et al. "Infant Botulism Following Honey Ingestion." BMJ Case Reports, 2012, doi:10.1136/bcr.11.2011.5153.

[9] "Infantile Botulism." StatPearls, StatPearls Publishing, 2025.