Most cases of otitis externa (OE) are caused by superficial bacterial infections and can be treated with over-the-counter analgesics and topical eardrops. Commonly used topical eardrops are acetic acid drops, which change the pH of the ear canal; antibacterial drops, which control bacterial growth; and antifungal preparations. Oral or parenteral antibiotics are reserved for severe cases. Otic antibiotic and steroid combinations have shown to be highly successful in treatment. The corticosteroid ingredient decreases inflammation and can help to ease the pain. These eardrops treat bacterial infection and reduce canal edema. The agents commonly prescribed for treating otitis externa are associated with cure rates between 87% and 97%.  In severe cases, oral or intravenous (IV) antibiotic therapy and narcotic analgesics may be required.
Most cases of OE are caused by superficial bacterial infections. Accordingly, most individuals with this condition may be treated with topical antibiotic preparations. Some preparations also contain a corticosteroid ingredient. The small amount of steroid that is present in the solution can help to ease the pain and edema associated with OE.
Hydrocortisone/neomycin/polymyxin B (Cortisporin, Cortomycin)
Hydrocortisone/neomycin/polymyxin is an antibacterial and anti-inflammatory agent for otic use, available as a solution or a suspension. It is used to treat steroid-responsive inflammatory conditions for which a corticosteroid is indicated and in which bacterial infection or a risk of bacterial infection exists.
Otic ofloxacin is a pyridine carboxylic acid derivative with broad-spectrum effect that inhibits bacterial growth by inhibiting DNA gyrase. It is available as a 0.3% (3 mg/mL) solution.
Otic ciprofloxacin is a fluoroquinolone that inhibits bacterial synthesis (and thus growth) by inhibiting DNA gyrase. It has activity against pseudomonads, streptococci, methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus epidermidis, and most gram-negative organisms but has no activity against anaerobes. It is available with or without hydrocortisone. Cetraxal is an otic solution available as 14 single-use applicators containing 0.25 mL of 0.2% solution each. Ciloxan is an ophthalmic solution that may be used for OE.
Tobramycin interferes with bacterial protein synthesis by binding to 30S and 50S ribosomal subunits, thereby causing defects in the bacterial cell membrane. Dexamethasone decreases inflammation by suppressing migration of polymorphonuclear leukocytes (PMNs) and reducing capillary permeability. TobraDex is an ophthalmic solution that may be used for OE.
Gentamicin is an aminoglycoside antibiotic used for gram-negative bacterial coverage. It is available as an ophthalmic solution that may be used for OE. This solution is a compounded medication, with each 1 mL containing 3 mg of gentamicin sulfate and 1 mg of betamethasone sodium phosphate.
Ciprofloxacin is a fluoroquinolone that inhibits bacterial DNA synthesis (and thus growth) by inhibiting DNA gyrase and topoisomerases, which are required for replication, transcription, and translation of genetic material. It has activity against pseudomonads, streptococci, MRSA, S epidermidis, and most gram-negative organisms but not against anaerobes. Dexamethasone decreases external auditory canal (EAC) inflammation by suppressing migration of PMNs and reducing capillary permeability; it also relieves pain symptoms.
This otic suspension is indicated for use in OE, as well as for use in otitis media in individuals with tympanostomy tubes.
Ciprofloxacin is a fluoroquinolone that inhibits bacterial DNA synthesis (and thus growth) by inhibiting DNA gyrase and topoisomerases, which are required for replication, transcription, and translation of genetic material. It has activity against pseudomonads, streptococci, MRSA, S epidermidis, and most gram-negative organisms but not against anaerobes. Hydrocortisone decreases inflammation by suppressing migration of PMNs and reducing capillary permeability.
Inflammation and accumulated debris allow the growth of bacterial species. This growth is counteracted by the use of mild acidifying medications, such as acetic acid solutions. These agents are useful for fungal OE or for mild OE believed to be of bacterial origin. They can also be useful for prevention.
Acetic acid in aluminum acetate (Borofair)
Aluminum acetate has a drying effect. Acetic acid works well in superficial bacterial infections of OE.
Acetic acid is antibacterial and antifungal; hydrocortisone is anti-inflammatory, antiallergic, and antipruritic. The combination of the 2 agents is inexpensive and works well in treating superficial bacterial infections of OE.
Alcohol vinegar otic mix
A homemade mix of 50% rubbing alcohol, 25% white vinegar, and 25% distilled water is as effective as pharmaceutical acidifying agents and less expensive. It is very useful for prevention and can be used as a flushing solution for fungal infections.
Oral antibiotics are used to treat severe infection or cellulitis. Fluoroquinolones are the drugs of choice by virtue of their coverage of Pseudomonas species.
Ciprofloxacin is a fluoroquinolone that inhibits bacterial DNA synthesis (and thus growth) by inhibiting DNA gyrase and topoisomerases, which are required for replication, transcription, and translation of genetic material. It has activity against pseudomonads, streptococci, MRSA, S epidermidis, and most gram-negative organisms but not against anaerobes.
OE can be quite painful, and control of this pain is essential to quality patient care. Analgesics ensure patient comfort and may have sedating properties. Inexpensive, simple nonsteroidal anti-inflammatory drugs (NSAIDs) reduce inflammation and irritation and can be paired with opiates to improve pain symptoms.
Over-the-counter acetaminophen is appropriate for most patients. It is the drug of choice for pain in patients who are known to be hypersensitive to aspirin or NSAIDs, who have upper GI gastrointestinal (GI) disease, or who are taking oral anticoagulants.
The combination of acetaminophen and codeine is indicated for the treatment of mild to moderate pain.
A small but significant percentage of OE cases are due to Aspergillus species or other yeasts and fungi (otomycosis). Some cases of fungal OE can be treated with acidifying drops; topical antifungal agents are used to treat otomycosis refractory to these drops. The mechanism of action of topical antifungal agents usually involves inhibition of the pathways (eg, enzymes, substrates, and transport) necessary for sterol/cell membrane synthesis or those involved in altering the permeability of the fungal cell membrane (eg, polyenes).
Otic clotrimazole solution is a compounded medication. Clotrimazole is a broad-spectrum antifungal agent that inhibits yeast growth by altering cell membrane permeability, causing the death of fungal cells.
Nystatin is a fungicidal and fungistatic antimicrobial obtained from Streptomyces noursei; it is effective against various yeasts and yeastlike fungi. It changes the permeability of the fungal cell membrane after binding to cell membrane sterols, causing the cellular contents to leak. Treatment should continue until 48 hours after the disappearance of symptoms. Topical application of nystatin reduces fungal growth.
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