CHAPTER 8

RISK FACTORS FOR OTITIS MEDIA

Ear infection is called otitis media [OM]. Fluid in the middle ear is called middle ear effusion [MEE].

There are many risk factors for children developing OM and/or MEE. Children with Eustachian tube Irritation [ETI] usually have several risk factors operating.

It is always hard to know the influence of each factor for an individual child, but the more risk factors that any child has, the greater the risk that OM or MEE will be a significant problem for that child.

I will describe risk factors in alphabetical order, rather than in order of potential severity of risk, as it is impossible to decide the severity of risk because of the….


AGE

The most common age for children to develop ear infections is from six months to two years.

Many children will grow out of having ear problems by the time they are about three years old. The reason for the improvement is the better functioning of the Eustachian tube [ET] and also the maturation of immune function. See the chapter about The Ear and also the section below about Immunity.

However a proportion of children will continue….


ALLERGIES AND INTOLERANCES

The issues of allergy and intolerance have been described in detail in the chapter about Allergies and Intolerances.

Briefly, many children who are prone to develop recurrent ear infections [and especially persistent MEE] have allergies and intolerances. These children are described as ‘atopic’.

People who have allergies and intolerances have tissues that react excessively when they come into contact with a substance to which they are allergic or intolerant and to chemical irritants. The reaction produces swelling of the tissues and excess production of mucus. In the upper respiratory tract this can interfere with ET function, preventing normal middle ear ventilation. This makes it difficult for the ET to keep the middle ear [ME] at atmospheric pressure. Effusion often follows. When fluid is present, there is an increased risk of developing ear infection.

In infants, intolerances are far more common than allergies, although some infants may already have true food allergies [e.g., milk allergy]. Food intolerances are common in children who have a family history of atopy [allergy]. By far the most common is intolerance of dairy products. This may be produced through the mother’s intake of foods containing dairy protein while breast feeding or from direct intake by the child. Reactions to dairy protein may cause colic, reflux, snuffliness—and increase the risk of MEE developing and persisting.

As the child grows and matures, allergies are more likely to be caused by aeroallergens [air borne or inhaled allergens]: particularly dust mite, grasses, pollens, cat and dog dander, feathers and moulds. The types of symptoms also change, with particularly allergic rhinitis [hay fever], and asthma becoming more common.

There is much written about the causes of allergies and why there has been a huge increase in the number of people with allergies compared with a generation ago. These factors are also discussed in detail in the previous chapter. The ‘too clean’ theory has been widely accepted. This theory suggests that households are now much cleaner than a generation ago and this reduces challenges to the child’s immune system by infections in the first few months or years of life, so the immune system is activated as allergies….