Otitis Externa - Ear Ache - Symptoms and Treatment
Otitis externa is inflammation of the outer part of the ear, also called the external ear. In this paper we explain the anatomy of the external ear, the symptoms and treatment of otitis.
To understand what otitis externa is and what its potential complications are one must first learn a little about the anatomy of the external ear.
Anatomy of ear
The outer ear consists of the pinna (ear) and the ear canal, ending at the tympanic membrane. After the eardrum, there is the region of the middle ear. When there is an inflammation anywhere in the outer ear, we call it otitis externa. When inflammation occurs in the area behind the eardrum, it is called otitis media.
The external auditory canal is a cylindrical duct about 2.5 cm long and 1cm in diameter. It begins and ends in the ear through the tympanic membrane.
The outer part of the ear canal is lined with a thicker skin with numerous adnexal structures such as glands that produce earwax, sebaceous glands and hair follicles. The inner part of the channel nearest to the eardrum, contains a thin and fragile skin, without the subcutaneous tissue. The skin in this area is in direct contact with the underlying bone. Thus, minimal inflammation or canal alteration (such as using objects to scratch the ear) are capable of causing significant pain and / or injury.
Our canal has some intrinsic defense mechanisms that hinder the occurrence of infections:
The anatomy of the ear itself is already protective because it partially covers the ear canal, hindering the entry of extraneous objects. Another factor that prevents extraneous objects is that the ear canal presents a more refined area, which prevents, for example, a finger to reach the eardrum. The presence of hair in the outer ear canal also acts as a barrier.
The production of earwax is also essential, because beyond the physical barrier, it causes a decrease in the pH of the ear canal, inhibiting the growth of fungi and bacteria. The wax is also a hydrophobic substance, which helps to lower the humidity inside the ear.
The ear is a "self-cleaning" organ. The skin of the ear canal increases from the inside out, which will naturally push the dirt, excess wax and clean the ear.
Like various parts of our body, the canal has its own flora of bacteria that normally do not cause health problems and even hinder the arrival of more aggressive bacteria. Wounds in the ear canal may facilitate penetration of bacteria into deeper tissues causing infection. Most of otitis externa are caused by the bacterium Pseudomonas aeruginosa, an invading bacterium not normally colonizing the ear canal. Bacteria that normally inhabit the ear, Staphylococcus aureus is the one that causes more ear infections, especially if there is a wound in the skin of the ear canal.
Otitis externa usually arises when some of the protection systems mentioned above is broken.
Exposure to water is a well-documented risk factor for otitis externa. Excess moisture leads to maceration of the skin and breaks the barrier of wax, changing the microflora of the ear canal, favoring the growth of bacteria that cause ear infections. Otitis externa is also known as swimmer's ear infections.
Traumas such as excessive (or aggressive) cleaning of the ear, not only remove cerumen, but also can create scratches along the thin layer of skin in the ear canal, allowing bacteria have access to deeper tissues. Moreover, part of a cotton swab can loosen up or a small piece of tissue paper can be left behind in the ear canal, these remnants can cause a severe skin reaction, leading to infection.
The use of a swab pushes wax further into the canal. This wax tablet can act as a stopper and only comes out with the help of an otolaryngologist. As has been already said, the ear does not need to be cleaned, it is able to expel the wax and impurities. The swab can hurt the ear canal and prevent "self-cleaning" of the ear.
Frequent use of devices that occlude the ear canal, such as hearing aids, earphones (earphones) or diving plugs also predispose to otitis externa.
Allergic contact dermatitis can lead to external otitis (for example, earrings or allergy to chemicals in cosmetics or shampoos), as well as other dermatological conditions such as psoriasis, or atopic dermatitis.
Otitis externa can occur at any age but is most common in children between 7 and 12 years.
The most common symptoms of otitis externa are pain, itching, feeling of blockage and discharge of fluid from the ear. The ear pain in otitis externa is usually very strong and worsens when pulling or tightening ear. Some palpable lymph nodes in the neck on the side of the affected ear can arise.
On examination with otoscope it is possible to notice very swollen and red ear canal, typical signs of inflammation. The fever usually occurs only in severe cases.
Malignant otitis externa, also called necrotizing otitis externa, is a serious and potentially fatal complication of acute bacterial otitis externa. More common in diabetic patients, the elderly and immunocompromised, it occurs when the infection spreads from the skin to the bone and marrow spaces of the skull base (also involving soft tissue and cartilage of the temporal region).
Patients with necrotizing otitis externa usually have severe pain and purulent discharge. Swelling, redness and frank necrosis of the skin of the ear canal may be visible at otoscopy. Cranial nerve palsies are a sign of poor prognosis.
Malignant external otitis can lead to brain abscess and meningitis.
The diagnosis is made with MRI or CT scan, showing the progression of the infection to the bone structures. Patients suspected of having malignant otitis externa should be immediately referred to an otolaryngologist.
In some cases your doctor will flush the ear with water and hydrogen peroxide before beginning treatment. This accelerates healing, removing dead skin cells and excessive ear wax.
The prescription of ear drops is used to reduce pain and swelling caused by otitis externa. These drops usually contain a combination of corticosteroids, antifungals and antibiotics. Do not use drugs on your own, before using any medicine to treat an ear infection you need to make sure the eardrum is not perforated.
The correct application of the drops is essential for them to reach the ear canal:
Lie on the side or tilt your head to the opposite shoulder.
Fill the ear canal with drops.
Lie on the side for 20 minutes and place a cotton ball in the ear canal.
You should feel better within 36 to 48 hours after starting treatment. If your pain gets worse or there are no signs of improvement in this time period, call your doctor. Analgesics or anti-inflammatory tablet may be used for pain relief.
Avoid wetting the ears during treatment. During having a bath you can put a cotton ball coated with Vaseline in the ear. Avoid swimming for at least ten days after beginning treatment. Also avoid using hearing aids and headsets until the pain disappears.
