Sandbox:Otitis externa classification

# Overview
Otitis externa is classified as acute, chronic, or malignant based on the duration of the disease, as well as diffusion and severity of infection and symptoms.

# Classification
Otitis externa is classified by duration, diffusion, and symptom severity.

## Acute Otitis Externa
- Otitis externa is characterized as "acute" if the following conditions are satisfied:
Onset within 48 hours.
Primarily caused by bacterial infection of Pseudomonas aeruginosa and Staphylococcus aureus.
Otalgia and feelings of itchiness or "fullness" of the ear canal.
Erythema or edema of ear canal.
Tenderness of the tragus and pinna.
- Onset within 48 hours.
- Primarily caused by bacterial infection of Pseudomonas aeruginosa and Staphylococcus aureus.
- Otalgia and feelings of itchiness or "fullness" of the ear canal.
- Erythema or edema of ear canal.
- Tenderness of the tragus and pinna.
- Hearing loss is not usually associated with acute presentations of otitis externa.
- Acute otitis externa is treated with topical or systemic antibiotics for 7-10 days.
- Clinical response will usually be seen within 48-72 hours; full symptom resolution is usually achieved within 14 days.
- Acute otitis externa is localized to the ear canal and is not characterized by diffusion of infection throughout the ear and head.

## Chronic Otitis Externa
- Otitis externa is considered chronic for cases that persist greater than 3 months with treatment.
Usually, it is diagnosed for cases in which antibiotic therapy does not alleviate symptoms.
- Usually, it is diagnosed for cases in which antibiotic therapy does not alleviate symptoms.
- Chronic otitis externa is primarily caused by the following:
Otomycosis, particularly by Candida albicans and Aspergillus niger
Allergic rhinitis
Underlying dermatoses:
Eczema
Seborrhea
Psoriasis
Contact dermatitis
- Otomycosis, particularly by Candida albicans and Aspergillus niger
- Allergic rhinitis
- Underlying dermatoses:
Eczema
Seborrhea
Psoriasis
Contact dermatitis
- Eczema
- Seborrhea
- Psoriasis
- Contact dermatitis
- Symptoms of chronic otitis externa are predominantly itching, due to the presence of dermatalogical condition or fungal debris.
Otorrhea is more common in chronic otitis externa than the acute presentation.
- Otorrhea is more common in chronic otitis externa than the acute presentation.
- Treatment of chronic otitis externa resolves around treating the underlying condition, including corticosteroid therapy for dermatological conditions and topical anti-fungal medications for otomycosis.

## Malignant Necrotizing Otitis Externa
- Acute otitis externa becomes reclassified as malignant and necrotizing when the infectious pathogen diffuses from the ear canal and infects the temporal bones, as well as bones in the ear adjacent to the canal, leading to damage and degradation.
- It is usually caused by the bacterial pathogen responsible for the acute variant, usually Pseudomonas aeruginosa.
- Otitis externa becomes malignant when the patient is immunocompromised.
It usually occurs in acute otitis externa patients with diabetes or undergoing chemotherapy, leading to reduced ability to counter the spread of the pathogen.
- It usually occurs in acute otitis externa patients with diabetes or undergoing chemotherapy, leading to reduced ability to counter the spread of the pathogen.
- Malignant otitis externa will usually manifest with the following symptoms:
Severe otalgia and otorrhea that is not responsive to treatment.
Granulated tissue in the ear canal
Intracranial and neck complications:
Fever
Nerve damage in the head and neck.
Osteitis
Lymphadenitis
Difficulty speaking or swallowing.
Facial palsy
- Severe otalgia and otorrhea that is not responsive to treatment.
- Granulated tissue in the ear canal
- Intracranial and neck complications:
Fever
Nerve damage in the head and neck.
Osteitis
Lymphadenitis
Difficulty speaking or swallowing.
Facial palsy
- Fever
- Nerve damage in the head and neck.
- Osteitis
- Lymphadenitis
- Difficulty speaking or swallowing.
- Facial palsy
- Treatment of malignant otitis externa requires therapy targeting the pathogen as well as the source for immunocompromisation.