Because of this, it is very important that Healthcare Professionals pay close attention to both the signs and symptoms and listen to parents who will know what is normal for their child and may be able to provide valuable insights.

Because infants may suffer a broad range of conditions, this article takes a selective look at some of the most important and common conditions that affect infants under the age of 1 year, concentrating on medical diseases rather than accidents. The article has mostly been based on guidelines, systematic reviews and searches of all the literature on this subject.

Developmental and immunilogocal immaturity
This age group present a particular challenge for practitioners because of their susceptibility to a range of conditions, and their relative difficulty in diagnosis, resulting from immunological immaturity and inability to talk about their symptoms. Because they can`t meet their own nutritional and hygiene needs, they are dependent upon carers to maintain high standards, for example in milk preparation and storage, and general hygiene. Symptoms that may indicate infection such as coughs, colds, crying, irritability and wheezing are also very common. Most of these symptoms are managed successfully by parents without consulting with Healthcare Professionals¹.

Vaccines
In order to provide immunity at the earliest possible age, increasing numbers of vaccines are given during infancy. In the United Kingdom, vaccinations start at the relatively young age of 2 months. The vaccine schedule has recently been expanded to include pneumococcus (Prevenar), however there are many common conditions which are not included. This may be either because vaccines are not available (such as respiratory syncytial virus), or because it is not thought that they should be given in the United Kingdom (such as varicella-zoster or chicken pox). The latest information is available from the Department of Health website www.dh.gov.uk.

Infants derive some protection from the presence of maternal antibodies (also known as immunoglobulins, shortened to Ig). Some are transferred while still in the womb (IgG), while others, such as IgA, the most important secretory mucosal antibody is found in breastmilk, providing breastfed babies with protection against germs which enter mostly through the mouth and throat². Breastfeeding also encourages a more normal gut flora, that is the `good` pathogens that inhabit our gut and fight-off disease and allergy-causing bugs. This is because breastmilk contains high levels of prebiotic oligosaccharides (OS), which are the food of these benign pathogens (Bifidobacteria). Maternal IgG lasts in the circulation for around 12 months, and the mucosal antibody IgA for as long as the baby is breastfeeding³. Some infant formulas, like Cow and Gate first contain a patented blend of prebiotics OS which have been shown to increase the number of bifidobacteria in the gut.

Protective Effect of Maternal Antibodies in Serum and Milk.



Antibiotic use
Although widely used, antibiotics have no effect against most childhood infections which are of viral origin. There are also disadvantages to antibiotic use, including allergy, damage to the body`s normal flora, and the development and spread of antibiotic resistance⁴. Recently, concern has grown about community acquired MRSA, which has been isolated from children⁵.

The appropriate and targeted use of antibiotics prior to commencing or changing treatment is important⁶. Healthcare professionals need to ensure that children who require antibiotic treatment receive the correct dosage at the right time, not allowing them to be over-prescribed, while of course keeping parents informed.

Feverish disease in infants
Many conditions result in fever, and although it can be a cause of anxiety, it is actually a normal response to infection. The key task is to isolate the symptom of fever from the underlying cause, because while fever itself does not require treatment, it may be a sign of a condition that does, even in the absence of other classic signs of infection. Unfortunately, there is little consensus about what temperature constitutes a fever, and this differs between various measurement sites.

Although temperature is a very common measurement, it can be misleadingly low if not undertaken correctly. In infants under 4 weeks of age, an electronic thermometer placed under the armpit should be used. For those older than this, a chemical dot thermometer or infrared ear (tympanic) thermometer may be used. When using the latter, it is important that the correct technique is used to straighten the ear canal⁷ (see Figure 1). Forehead and mercury thermometers should not be used, neither should the rectal route. Latest full guidelines can be found on the Medicines and Healthcare Products Regulatory Agency website at www.mhra.gov.uk

Figure 1. MHRA `Infra-red Ear Thermometer - Home Use Guidelines`.

The recently published National Institute of Clinical Excellence (NICE) guidelines regarding the treatment of fever in children⁸ use a `traffic light` system to classify signs and symptoms as being green, amber or red, depending upon the likelihood of them indicating serious illness. Based upon these factors the guidelines provide recommendations about further assessment and treatment (see Figure 2).

Figure 2. NICE Traffic Light System

Additionally some signs and symptoms, which indicate particular conditions are provided (see Figure 3).
Figure 3. Summary table for symptoms and signs suggestive of specific diseases

(Tables reproduced by kind permission from NICE www.nice.org.uk)

It is recommended that all Healthcare Professionals should measure and record temperature, heart rate, respiratory rate and capillary refill time in these children, as these are considered to be particularly important indicators of illness. Although antipyretic medications are not recommended for routine use, if paracetamol or ibuprofen are advised, care should be taken to ensure that parents understand their safe use. Physical treatments such as tepid sponging and undressing are not recommended as they have a short-term effect and may cause rigours.

If parents are seen and discharged home, they should be advised to seek further advice if their child has a fit, develops a non-blanching rash, if their general condition appears to be worsening or if the fever persists beyond 5 days, or if they are worried, distressed, or unable to care for their child. General advice of encouraging rest and fluid intake should also be given. Healthcare Professionals should respond positively to parental concerns, particularly with regards to changes in their child`s condition.

Febrile convulsions
A febrile convulsion is a seizure in a child under the age of 5 years occurring in conjunction with a fever in the absence of previous afebrile seizures or underlying neurological, central nervous system (CNS) infection, or similar condition. Most are classified as being simple, being generalised in nature, lasting less than 15 minutes, and only occurring once a day. It is estimated that between 2-4% of children will suffer a febrile convulsion ⁹. The most important aspect of assessment is to differentiate those children with severe bacterial infection from those with other self-limiting conditions.

Although associated with fever, the reason why some children have febrile convulsions is not known. Because they are benign in most cases and children grow out of them at around the age of 5 years, anticonvulsant treatment for simple convulsions is not necessary. Further medication is not effective¹⁰. Although simple febrile convulsions themselves do not require treatment, the underlying cause may, and the key task is the differentiation of simple from complex convulsions¹¹

Urinary tract infections
Urinary tract infections (UTI) are very common, affecting around 4% of boys and 11% of girls in childhood, and were the subject of recent NICE guidelines¹². The symptoms of many UTIs are not specific, typically being fever, vomiting, lethargy, irritability, poor feeding and sometimes failure to thrive. In older infants they include abdominal pain, loin tenderness, vomiting, poor feeding, changes in urinary pattern or incontinence, and offensive smelling urine. Because of this, UTI should be considered in any infant with unexplained fever and a urine test undertaken. Samples should be cultured immediately, if this is not possible within a 4 hour time-period, the sample should be refrigerated until it can be processed in the laboratory.

All infants under the age of 3 months with suspected UTI should be referred to a paediatric specialist. For infants over the age of 3 months who have specific urinary symptoms, microscopy and cultures should be undertaken immediately and antibiotic therapy commenced. For children with a lower risk of serious illness, while microscopy and culture should still be performed, as a first-line test a urine dipstick can be used, a positive dipstick test for nitrites suggesting infection.

Respiratory tract infections
The respiratory tract includes the upper and lower respiratory tract and the ear, nose and throat. Most upper respiratory tract infections are viral, self-limiting and do not require treatment, although symptomatic treatment may be required. Lower respiratory tract infections include pneumonia and bronchiolitis, the latter being the most common. The most common infection of the ear is otitis media.

Bronchiolitis
Bronchiolitis is an infection of the bronchioles in the lower-respiratory tract. This can be caused by a variety of viruses including respiratory syncytial virus (RSV), influenza, parainfluenza viruses, rhinoviruses, adenoviruses, and human metapneumovirus¹³. It occurs on a seasonal basis, with epidemics in the winter months. Most children can be treated at home, with information to seek further advice if the child`s feeding reduces, they become lethargic, or if the nature or rate of breathing changes.

Because this is viral condition, antibiotics have no effect. A small number of babies, such as those with congenital heart disease, immune deficiency, or extreme prematurity, can receive prophylactic palivizumab, a respiratory syncytial virus (RSV) antibody preparation antibody preparation. Treatment in hospital will primarily be supportive, while other treatments such as steroids and bronchodilators are not recommended¹⁴.

Acute otitis media
Acute otitis media (AOM) is rapid onset of inflammation of the middle ear, this contrasts with otitis media with effusion which includes the accumulation of fluid in the middle ear, but without the acute inflammation. Otitis media has a number of non-specific symptoms, such as fever, irritability, lethargy, loss of appetite and vomiting. Specific signs include discharge and earache. Otoscopy shows a bulging tympanic membrane with loss of normal landmarks, change in colour (normally red or yellow)¹⁵. It is caused by a variety of bacteria and viruses and, unfortunately, it is not possible to differentiate these without microscopy and culture.

The Scottish Intercollegiate Guidelines Network (SIGN) guidelines recommend that antibiotics need not be routinely pres

Gastrointestinal infection
The gastrointestinal tract (GI) extends from the mouth to the rectum and is populated by a wide variety of microorganisms which help to protect the body from infections.
Probiotic OS, sometimes referred to as `friendly` bacteria, aim to supplement the normal flora of the bowel. They have a number of potential benefits, including alleviation of the symptoms of lactose intolerance, relief from constipation, the prevention and recovery from diarrhoea, and a reduction in food and other allergies. These result from their physical presence in the GI tract, antimicrobial and other substances that they produce, and stimulation of the immune system¹⁷. Prebiotic OS are non-digestible carbohydrates that encourage the growth and maintenance of a healthy gastrointestinal flora¹⁸. As stated above, breastfed babies enjoy the benefit of high levels of Prebiotic OS in mothers` milk; formula milk that is supplemented with such substances may be beneficial to gastrointestinal flora in the same way.

Diarrhoea
Diarrhoea can result from a number of causes, usually as the result of viral infection, but also bacteria and less commonly protozoa. The aim of treatment is to reverse any dehydration, and maintain hydration. General signs of dehydration include tachycardia, reduced peripheral perfusion and reduced urine output. The eyes and fontanelles may be sunken, although this may be difficult to assess in individual children¹⁹.

Most children with diarrhoea should be treated with an oral rehydration solution such as Dioralyte. These electrolyte solutions are carefully formulated and should not be altered or substituted with homemade equivalents. The initial rehydration stage should be completed over 3 to 4 hours, before moving onto the maintenance stage. In most cases, normal age appropriate diet can be maintained, and breastfeeding should be continued. Normal water lacks electrolytes and does not provide any calories, and formula feed should not be diluted. Fluid losses can be estimated by weighing nappies before and after changing them, with 1g of weight roughly equating to 1ml of fluid loss, and the aim of maintenance is to match these losses.

Children with no dehydration and who are tolerating oral feeds can be managed at home. If they are not tolerating oral fluids, they should be observed and admission considered. Mild to moderately dehydrated children should be observed during the rehydration phase and until they are reliably taking fluids. More dehydrated children, those with uncertain diagnosis or significant vomiting should be considered for admission for observation. The ability of parents to manage at home should also be assessed.

Drug therapies are rarely indicated. Antibiotics are ineffective against viruses, and are rarely useful even in bacterial infections. The benefit of using probiotic OS to prevent antibiotic-associated diarrhoea has yet to be demonstrated²⁰.

Allergy
Allergic reactions occur as the result of inappropriate production or levels of IgE, resulting in the release of chemicals from cells such as basophils and mast cells. These include histamine, causing the generalised inflammation and other signs associated with allergy. Because IgE is produced in response to a specific substance, the initial exposure to that substance results in sensitisation, and it is subsequent exposures that lead to the symptoms of allergy. Severe systemic allergy may result in anaphylaxis which can be life-threatening. The term allergy is when an immunological mechanism has been demonstrated, other reactions being non-allergic food hypersensitivities²¹.

Although the reports of food related allergies are increasing, data are limited. A recent study of parental reports at 12 months in Oslo showed the most commonly implicated foods were cows` milk, hens` eggs, various fruit and vegetables, and fish. Nut allergy was relatively rare in the first year, but became increasingly important in older children²². Many parents are particularly concerned about vaccinations; but in fact the incidence of vaccine related anaphylaxis is very low. Many of the symptoms that parents may report as allergy, such as fever and localised reactions and rashes, are actually the result of normal immune responses to vaccination.

Over-diagnosis of allergy is significant because it may lead to unwarranted treatment and expense. Often the concern is about food and excluding these foods from the diet may result in inadequate nutrition and growth. In the case of vaccines, it may lead parents to miss vaccinations. In cases where parents will not consent to vaccination, a referral should be made to the local vaccine co-ordinator for further follow-up.

Some children with allergies will progress to other allergic conditions, this is known as atopy²³. The incidence and prevalence of atopic disease has increased significantly over recent years. One possibility for this is the `hygiene hypothesis` which states that improved home hygiene and a consequent lowering of the infection rate in early childhood prevents the development of normal immunological responses. This remains controversial however, and it is important not to reduce levels of personal hygiene that might increase the risk of gastrointestinal and other potentially significant infections in susceptible young children²⁴, particularly in day-care facilities, where groups of children form a significant source of cross-infection²⁵.

Conclusion
Infants are particularly susceptible to a variety of conditions because of their developmental and immunological immaturity. By being aware of the main culprits and ensuring a body of knowledge about their symptoms and therapies front-line Healthcare Professionals are better placed to alleviate parents concerns while ensuring the best initial interventions or referrals when needed.

Click here to download Childhood illness and allergy `Glossary`

Written by Edward Pursell RGN RSCN BSc MSc PhD. Lecturer, Department of Primary and Intermediate Care, King`s College London. Published in N&N issue 14 - July 2008.

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