This page addresses some commonly asked questions and provides links to detailed information from trusted sources. Please note this content is general in nature and is not a substitute for individualised medical advice. This information is valid as of April 2025.
Terminology about food reactions can be confusing, since reactions with very different causes are often referred to using the same words. The main types of reactions are:
For more detail about different types of reactions to foods, refer to this ASCIA page.
Small amounts of mucus in the stool in a well infant is normal. This mucus may be produced by healthy gut bacteria and may play a role in helping stool pass smoothly.
Large amounts of mucus and/or any blood in the nappies would make us think about other causes, such as infection. Mucusy stool with fresh blood in a healthy, thriving baby is commonly due to a delayed reaction by the immune system to a food protein (often cow's milk). Although sometimes called cow's milk protein allergy, this condition is not a 'true allergy' (see above), and does not cause immediate symptoms like hives, or anaphylaxis. Other less common causes of mucus or blood in nappies should also be considered and a thorough assessment by a GP or paediatrician is always warranted.
Lactose is a sugar found in milk (including breastmilk and cow's milk), and its digestion involves an enzyme called lactase. Lactose intolerance occurs when there is not enough of the lactase enzyme in the gut, leading to symptoms such as tummy pain, bloating and diarrhoea.
In infants and young children, lactose intolerance is usually a temporary problem after a viral illness like gastroenteritis, and it resolves within weeks. It is extremely rare for babies to be born with lactose intolerance, and much more common for it to develop in older children and adults.
The most important part of allergy diagnosis is the history, i.e. the description of symptoms linked to exposure to an allergy-causing substance (allergen). If an immediate-type allergy is suspected, a skin prick test, blood test or oral food challenge can help to confirm the diagnosis. A skin prick test involves pricking the skin with food extracts and looking for a wheal (swelling). Blood tests measure an immune molecule (IgE) that is targetting the food(s) of interest. A food challenge involves eating small amounts of a food under close medical supervision. The decision to carry out allergy testing requires careful consideration, since interpreting these tests is not straight-forward.
For delayed reactions or food intolerances, skin prick testing will not be useful. Other tests may be helpful depending on the condition, such as trialling elimination and reintroduction of the food, a formal oral food challenge, or specific testing for coeliac disease.
Allergens are substances that can cause allergic reactions in susceptible people. Common food allergens include cow's milk, egg, soy, tree nuts, peanut, sesame , wheat, fish and shellfish. Food allergens should be introduced from around 6-12 months of age along with other solids. Each allergen should be introduced by itself at first, and during the day, so that you can detect any symptoms of allergy in the rare instance that they occur. Peanut and tree nuts should always be crushed or given as pastes (e.g. nut butters) to infants and young children. Once introduced, try to keep giving allergenic foods regularly (e.g. twice a week) to maintain tolerance. For further information, look at this website.
Bedwetting is developmentally normal in young children. Part of the reason is that our bodies produce a hormone (called ADH) that helps us retain fluids overnight, and young children often don't make enough of this hormone. Deep sleepers may also not be woken by the urge to urinate. In an otherwise healthy child, bedwetting often doesn't need any treatment until at least 6-7 years of age. A medical review should be considered at this age, particularly if the bedwetting is causing distress to the child or family.
Rarely, bedwetting can be associated with another medical condition. A medical review should be sought if there are any concerning daytime symptoms such as unusual frequency of urination or daytime wetting in a child that was previously dry, or if a child who was previously dry at night for at least six months has started bedwetting again.
For more information read this factsheet from the Sydney Children's Hospital Network.
If bedwetting is associated with another medical condition, such as constipation, this should be treated first. Behavioural strategies like a bedwetting alarm are highly successful as treatment for bedwetting, but they must be used consistently for several weeks. It is rare to require further treatment such as medication for uncomplicated bedwetting.
The most common cause of constipation in young children is 'functional' constipation, which happens in toddlers and young children who may ignore the urge to defecate and then develop anxiety after having a painful bowel movement. Continued avoidance leads to stool building up in the rectum and large bowel.
Investigations (e.g. blood test, X-ray) are not needed to diagnose functional constipation, but may be required if other less common medical causes of constipation are suspected. For this reason, a careful medical assessment is always recommended.
Functional constipation is usually treated with a combination of strategies which may include diet and behaviour modification and medications such as stool softeners and laxatives. A common reason for treatment failure is stopping laxatives too early. It can take many months for the bowel to fully heal and resume normal functioning, so treatment often needs to be prolonged and tapered down gradually.
For further information, read this factsheet from the Sydney Children's Hospital Network.
For children with eczema, a good rule of thumb is to keep the skin 'cool, clean and moisturised', i.e.:
Eczema can flare in reaction to many different substances, including allergens like foods or dustmites, chemicals like chlorine or soap, and after a viral illness. Although rare, some people have reported a flare of eczema after a vaccine.
It can be impractical (or impossible) to avoid certain triggers, and in some cases there are potential harms in strictly avoiding a trigger. For example, a strict restrictive diet may lead to nutritional imbalances, while avoiding vaccination increases the risk of serious infections.
Maintaining excellent baseline care of eczema can help to minimise flares while allowing more flexibility in diet and lifestyle
Topical steroids (i.e. ointments or creams) are safe to use in children with eczema and should not be applied "sparingly" but in ample amounts to the affected areas. They can be stopped when the skin has healed, and regular moisturisers should be continued. Side effects are rare but are more likely with long term use of very strong steroids over large areas of skin.
In recent years concerns have increased about 'topical steroid withdrawal', a condition that is not very well understood. A British dermatology expert group has released this statement acknowledging that more needs to be learnt about this rare condition, but emphasising that topical steroids should continue to be used as needed.
Hayfever is an allergic reaction to environmental substances such as house dust mite, pollens, grasses and moulds. Symptoms include sneezing, runny nose and itchy eyes. It is also called 'allergic rhinitis'. Hayfever is uncommon under 2 years of age and gradually becomes more common, affecting about 1 in 3 adolescents.
The impacts of hayfever are often underrecognised. It can cause troublesome daytime symptoms, and can significantly impact sleep quality which in turn can affect daytime function, including attention and behaviour.
Hayfever can be diagnosed based on symptoms and examination findings. Testing is not needed to confirm the diagnosis, but can help to identify triggers, e.g. by skin prick testing.
The national schedule covers at least 15 diseases, but there are some additional vaccines that you might choose to purchase to provide additional protection for your family, e.g.:
Reflux (gastroesophageal reflux) is when the contents of the stomach come back up the foodpipe (oesophagus), sometimes into the mouth. All young babies have reflux, sometimes called 'posseting' or 'spilling' when the food is spat or vomited out. This occurs since the ring of muscle that separates the foodpipe from the stomach is weak in young babies, and since they are fed lying down. Reflux naturally improves from about 4 months of age, as the ring of muscle becomes stronger, and as they start to spend more time upright.
Most babies do not need any treatment for reflux, since it naturally improves over time. Treatment may be considered if there are concerning features such as signs of pain during feeding, feed refusal, poor weight gain or vomiting blood. If such features are present, the term 'gastroesophageal reflux disease' is used. Treatment options include positioning, feed thickeners and medication. For more information see fact sheet on reflux from the Sydney Children's Hospital Network.
'Tongue tie' is when the tissue that connects the tongue to the bottom of the mouth, called the lingual frenulum, is too short or tight, and may limit tongue mobility. Tongue mobility is important for breastfeeding babies, since the tongue plays an important role in drawing milk from the breast. However, most babies with tongue can successfully breastfeed without any intervention
Severe tongue tie can affect a baby's latch when breastfeeding. This can cause nipple pain, though it is worth noting that there are many other causes of nipple pain, most commonly incorrect positioning/latching. In rare cases, tongue tie can cause speech difficulties later in childhood.
Severe cases of tongue tie can be managed by cutting the restrictive tissue (frenotomy). This procedure should only be considered after a careful assessment of latching by an experienced health professional.