“Otitis externa” means inflammation of the ear in the area of the external auditory canal, which does not extend beyond the tympanic membrane.
Usually, this inflammation is caused by an infection.
External auditory canal
The ear receives the sound waves and converts them into electrical signals that are passed through the nerves to the brain.
The slightly curvy external auditory canal (meatus acusticus externus) begins on the outside of the ear at the auricle and extends to the eardrum.
The wall of the ear canal is formed by cartilage in the outer third, while the inner two-thirds are formed from bone.
The duct is about 2.5 cm long and is lined with skin that reaches up to the eardrum.
On this epithelium there are:
- hair directed outwards;
- Glands that produce the earwax (ceruminal glands).
Children and infants are most affected, but adults can also get sick.
Rarely, the disease occurs bilaterally.
Otitis media is another form of ear infection that affects the anatomical area of the middle ear; This includes:
- Ossicular chain (hammer, anvil and stirrup).
Inflammation of the ear canal is not contagious.
Classification of ear canal inflammation
Otitis externa can take several forms:
- Furunculous, if it occurs localized.
- Generalized, if it is diffuse and spreads throughout the ear canal.
Otitis externa maligna
In some cases, inflammation of the ear canal spreads to the outer auricle and surrounding tissues, such as the jawbone and facial area.
This particularly severe form of ear canal inflammation is called otitis externa maligna or progressive necrotizing otitis.
Otitis externa maligna is caused by the bacterium Pseudomonas aeruginosa.
This aggressive infection mainly affects patients with a weak immune system, such as:
- People with immunodeficiency.
The term “maligna” does not refer to a tumorous disease.
If left untreated, this infection of the ear can lead to death.
Causes of ear canal inflammation
There are various causes of otitis externa, as well as various factors that increase the likelihood of its occurrence.
- Bacterial infection – usually caused by bacteria: Pseudomonas aeruginosa or Staphylococcus aureus. It often occurs in summer, because people go to the sea, go to the swimming pool, sweat more or shower more often; the result is the entry of water into the ear canal, creating an ideal environment for bacteria to multiply.
- Seborrheic dermatitis – a common skin disease characterized by scaling, redness and crusting, which can sometimes also affect the ears.
- Infection of the middle ear or otitis media – The middle ear infection can also spread beyond the eardrum and cause ear canal inflammation.
- Fungal or yeast infection – Fungal infections are less common and are caused by different species of Aspergillus or Candida albicans. Sometimes they have them proven (Aspergillus, for example, causes black secretion), while in other cases it is not possible to find the culprit. Cotton swabs can transmit fungi, in addition, the use of cotton swabs can injure the skin in the external auditory canal and favor the development of infection.
- Irritation or allergic reaction – Otitis externa arises due to an inflammatory response to things that get into the ear, such as medicines, earplugs, or shampoo.
Otitis externa may also recur after previous therapy if treatment has not been completed completely and effectively.
Risk factors for ear canal inflammation
The following factors are not direct causes of otitis externa, but can increase the likelihood of developing this condition.
Water and moisture in the ear canal – The risk of otitis externa may increase:
- swimming (especially in dirty or polluted waters),
- due to excessive sweating,
- in humid environments.
The fluid in the ear canal is an ideal environment for bacteria and fungi.
Wind and cold are not risk factors for otitis externa.
Lesions in the ear – The ear canal is very sensitive and easily vulnerable to:
- heavy cleaning, especially with cotton swabs,
- Hearing aids.
Chemical products – The risk of otitis externa increases when irritating products are used near the ear, such as:
- Hair spray
- Hair dye.
Blockage of the ear canal – The blockage can be caused by:
- earwax plug,
- sebaceous cyst (atheroma),
- Abnormalities in the ear anatomy, such as a narrow ear canal or bone growth.
An ear canal blockage promotes inflammation of the skin and water accumulation in the ear.
Inflammatory skin diseases – can increase the likelihood of developing ear canal inflammation, for example:
Symptoms of ear canal inflammation
- Significant swelling of the external auditory canal.
- Transient hearing loss or hypakusis.
- Feeling of stuffy ears.
- Itch; this can be very intense, which is why the patient scratches and causes skin injuries.
- Earache; they worsen with touch and jaw movements. The earache is severe because the outer ear also consists of cartilage and cartilage skin and inflammation of these tissues is very painful.
- Lymph node enlargement around the ear.
- Usually, secretions are small, mucous and white, but can also be purulent (full of pus).
- With the presence of granulation tissue in chronic infection, the secretions are bloody.
Mycotic form (fungal infestation)
- secretion of whitish or downy secretions; other possible colors of the secretion are:
- Tinnitus or a ringing in the ears.
Form associated with seborrheic dermatitis
Typically, there is a comprehensive skin involvement, usually affected:
- ear with the auricle,
Inflammation of the ear canal caused by seborrheic dermatitis is characterized by:
- intense itching, which can lead to severe scratching;
- Reddening of the skin, thickening and numerous yellowish and greasy looking crusts.
In the case of ear canal inflammation due to psoriasis, the scalp is often also involved, less often the face.
In people with psoriasis in the ear canal, a thick red lesion appears with silvery-white scales.
Often the injuries itch.
Form associated with allergic contact dermatitis
It is an allergic reaction to allergens in:
- earrings containing nickel,
- Substances contained in hair care products.
It can occur suddenly.
The external auditory canal can react to the allergens even if they do not cause an allergic reaction
The auricle and earlobes may be affected.
- Ear canal inflammation: treatment and home remedies
- Tympanic membrane perforation: symptoms and causes
- Otitis media: symptoms and diagnosis