Swimming
Swimming in polluted water is a common way to contract swimmers ear, but it is also possible to contract swimmers ear from water trapped in the ear canal after a shower, especially in a humid climate. Prolonged swimming can saturate the skin of the canal, compromising its barrier function and making it more susceptible to further damage if the ear is instrumented with cotton swabs after swimming. Constriction of the ear canal from bone growth (Surfers ear) can trap debris leading to infection. Saturation divers have reported otitis externa during occupational exposure. Objects in ear
Even without exposure to water, the use of objects such as cotton swabs or other small objects to clear the ear canal is enough to cause breaks in the skin, and allow the condition to develop. Once the skin of the ear canal is inflamed, external otitis can be drastically enhanced by either scratching the ear canal with an object or by allowing water to remain in the ear canal for any prolonged length of time. Infections
The majority of cases are due to Pseudomonas aeruginosa and Staphylococcus aureus, followed by a great number of other gram-positive and gram-negative species. Candida albicans and Aspergillus species are the most common fungal pathogens responsible for the condition. Diagnosis
When the ear is inspected, the canal appears red and swollen in well-developed cases. The ear canal may also appear eczema-like, with scaly shedding of skin. Touching or moving the outer ear increases the pain, and this maneuver on physical exam is important in establishing the clinical diagnosis.
About 10% of people are affected at some point in their lives. It occurs most commonly among children between the ages of seven and twelve and among the elderly. It occurs with near equal frequency in males and females. Those who live in warm and wet climates are more often affected. Signs and symptoms
Tenderness of pinna is the predominant complaint and the only symptom directly related to the severity of acute external otitis. Unlike other forms of ear infections, we observe tenderness in outer ear i.e., the pain of acute external otitis is worsened when the outer ear is touched or pulled gently. Pushing the tragus, the tablike portion of the auricle that projects out just in front of the ear canal opening, also typically causes pain in this condition as to be diagnostic of external otitis on physical examination. People may also experience ear discharge and itchiness. When enough swelling and discharge in the ear canal is present to block the opening, external otitis may cause temporary conductive hearing loss.Because the symptoms of external otitis lead many people to attempt to clean out the ear canal (or scratch it) with slim implements, self-cleaning attempts generally lead to additional traumas of the injured skin, so rapid worsening of the condition often occurs. Causes
The two factors that are required for external otitis to develop are (1) the presence of germs that can infect the skin and (2) impairments in the integrity of the skin of the ear canal that allow an infection to occur.