Acute Suppurative Otitis Media


It is an acute inflammation of middle ear by pyogenic organisms. Here, middle ear implies middle ear cleft, i.e. eustachian tube, middle ear, attic, aditus, antrum and mastoid air cells.

Aetiology

It is more common especially in infants and children of lower socio economic group. Typically, the disease follows viral infection of upper respiratory tract but soon the pyogenic organisms invade the middle ear.

Routes of Infection

1. Via eustachian tube

. It is the most common route. Infectiontravels via the lumen of the tube or along subepithelial perituballymphatics. Eustachian tube in infants and young children is shorter,wider and more horizontal and thus may account for higher incidenceof infections in this age group. Breast or bottle feeding in a younginfant in horizontal position may force fluids through the tube intothe middle ear and hence the need to keep the infant propped upwith head a little higher. Swimming and diving can also force waterthrough the tube into the middle ear.

2. Via external ear. Traumatic perforations of tympanicmembrane due to any cause open a route to middle ear infection.

3. Blood-borne. This is an uncommon route.



Predisposing Factors

Anything that interferes with normal functioning of eustachian tube predisposes to middle ear infection. It could be:

1. Recurrent attacks of common cold, upper respiratorytract infections, and exanthematous fevers likemeasles, diphtheria, whooping cough.

2. Infections of tonsils and adenoids.

3. Chronic rhinitis and sinusitis.

4. Nasal allergy.

5. Tumours of nasopharynx, packing nose or nasopharynxfor epistaxis.
i
6. Cleft palate.

Bacteriology,

Most common organisms in infants and young children are Streptococcus pneumonia (30%), Hsaemophilus influenzae (20%) and Morexellacatarrhalis (12%). Other organisms include streptococcus pyogenes, staphylococcus aureus and sometimes pseudomas aeroginosa. In about 18-20%, no growth is seen. Many of the strains of H. influenzae and Morexella catarrhalis are b-lactamase producing.

Diseases run through the following stages