{
 "topic": "Otitis Externa",
 "slug": "otitis-externa",
 "category_id": 15741,
 "summary": "Diagnosing swimmer's ear by the 48-hour onset and tragal tenderness criteria, topical-to-oral antibiotic escalation, and when persistent otorrhea should trigger ENT referral or suspicion for MRSA or cholesteatoma.",
 "written_by": "claude-sonnet",
 "references": [
  {
   "title": "2021_Fleisher_&_Ludwig's_Textbook_of_Pediatric_Emergency_Medicine.epub",
   "author": null,
   "pages": []
  },
  {
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    512
   ]
  },
  {
   "title": "Pediatric Board Study Guide",
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   ]
  },
  {
   "title": "Pediatric ICD-10-CM 2023",
   "author": "American Academy of Pediatrics Committee on Coding and Nomenclature;",
   "pages": [
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   ]
  },
  {
   "title": "Pediatric Otolaryngology (American Academy of Pediatrics) ( etc.)",
   "author": null,
   "pages": [
    123
   ]
  },
  {
   "title": "Netters Pediatrics (Florin \u0422., Ludwig St.)",
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  {
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   "author": null,
   "pages": [
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   ]
  }
 ],
 "short": [
  {
   "title": "In short",
   "content": "- Otitis externa (\"swimmer's ear\") is inflammation of the external auditory canal, usually polymicrobial, especially common in school-age children, swimmers, and during summer/high humidity.\n- Pseudomonas aeruginosa is the leading cause (up to 60% of cases), followed by Staphylococcus aureus; other isolates include Enterobacter aerogenes, Proteus mirabilis, Klebsiella pneumoniae, streptococci, coagulase-negative staphylococci, diphtheroids, and fungi (Candida, Aspergillus) \u2014 fungal infection (otomycosis) is typically seen after prolonged topical antibiotic drop use.\n- Mechanism: cerumen normally coats the canal with a water-resistant, acidic, antibacterial layer; water trapped in the ear (swimming) disrupts this layer, and attempts to remove water or relieve itching (cotton swabs, other objects) cause trauma that creates a portal of entry for bacteria. Cerumen impaction trapping water is also a risk factor.\n- Diagnostic criteria (diffuse acute otitis externa): rapid symptom onset (within 48 hours) of otalgia, pruritus, and aural fullness, PLUS tenderness with manipulation of the auricular cartilage (tragus/pinna traction pain) \u2014 this traction tenderness helps distinguish otitis externa from otitis media with perforation. May have otorrhea, cervical lymphadenitis, or surrounding skin/pinna cellulitis.\n- Exam shows an erythematous, swollen, edematous external canal, often with debris, discharge, or purulent exudate.\n- First-line treatment: topical combination antibiotic/corticosteroid otic drops (e.g., polymyxin/neomycin or a fluoroquinolone) after canal debridement; a wick should be placed if canal edema is too severe for topical drops to reach the proximal canal.\n- Escalate to oral ciprofloxacin (covering Pseudomonas) for severe cases not responding to topical drops, or when the canal is too edematous to visualize the tympanic membrane \u2014 refer to ENT in that scenario, and the patient will need a temporary ear wick.\n- Systemic antibiotics are indicated when cellulitis extends beyond the external canal.\n- Malignant (necrotizing) otitis externa is osteomyelitis of adjacent bony/skull-base structures, seen especially in diabetic or immunosuppressed patients; suspect it with more severe pain, otorrhea, and possible cranial nerve palsies \u2014 imaging is essential for diagnosis, and P. aeruginosa is a key pathogen; it can be fulminant and necrotizing.\n- Persistent purulent otorrhea despite treatment warrants escalation: more than 2 weeks unresponsive to oral/topical antibiotics \u2192 refer to otolaryngology; more than 6 weeks unresponsive \u2192 consider cholesteatoma (squamous epithelial/keratin collection in the middle ear); more than 3 months despite multiple antibiotic courses \u2192 consider MRSA as the most common isolate."
  }
 ],
 "long": [
  {
   "title": "Definition",
   "content": "Otitis externa (external otitis, \"swimmer's ear\") is inflammation of the skin lining the external auditory canal, typically polymicrobial in origin. Diffuse acute otitis externa is diagnosed by rapid onset (within 48 hours) of otalgia, pruritus, and aural fullness, together with tenderness on manipulation of the auricular cartilage (tragus/pinna traction); associated findings may include otorrhea, cervical lymphadenitis, or cellulitis of the surrounding skin or pinna. It is particularly common in school-age children, in children who swim, and during summer months when humidity is high, though it can occur without swimming."
  },
  {
   "title": "Epidemiology",
   "content": "Otitis externa is a common childhood problem, especially during warmer months and among children who participate in water sports; the peak association with swimming gives the condition its common name, though it is not exclusively a swimming-related illness."
  },
  {
   "title": "Etiology",
   "content": "Pseudomonas aeruginosa is the predominant cause, isolated in up to 60% of cases, followed by Staphylococcus aureus. Other, less common bacterial isolates include Enterobacter aerogenes, Proteus mirabilis, Klebsiella pneumoniae, streptococci, coagulase-negative staphylococci, and diphtheroids; fungal pathogens such as Candida and Aspergillus (otomycosis) may also be isolated, typically in the setting of prolonged topical antibiotic drop use. Cerumen normally protects the canal by forming a water-resistant, acidic, antibacterial coating that prevents maceration; external otitis develops when this protective layer is disrupted, most often by water trapped in the canal from swimming, or by trauma from attempts to remove water or relieve itching (cotton swabs or other objects), which creates a portal of entry for bacteria. Cerumen impaction that traps water in the canal is a separate but related risk factor. Inflammation of the ear canal from herpesvirus, varicella-zoster virus, other skin exanthems, and eczema can also predispose to external otitis."
  },
  {
   "title": "Clinical features",
   "content": "Ear pain and, often, visible ear discharge are the usual presenting symptoms. Examination reveals an erythematous, swollen external canal, often filled with debris or purulent exudate. Traction on the auricle (or pressure on the tragus) reproduces or worsens pain in otitis externa \u2014 a finding that helps distinguish it from otitis media with perforation, where such traction is not typically painful. Associated cervical lymphadenitis or cellulitis of the surrounding pinna/skin can occur in more significant cases."
  },
  {
   "title": "Diagnostics",
   "content": "Diagnosis is clinical, based on the characteristic symptom onset and exam findings; a thorough debridement of the external auditory canal, when feasible, both confirms the diagnosis (by revealing the inflamed canal directly) and initiates treatment by removing debris that would otherwise block topical medication delivery. In severe or refractory cases, cultures of canal exudate can be sent to identify the specific causative organism and guide antibiotic selection. In patients with diabetes or immunosuppression, evaluate carefully for malignant (necrotizing) otitis externa \u2014 osteomyelitis of the adjacent bony structures \u2014 which presents with more severe pain and otorrhea and may include cranial nerve palsies; imaging is essential to make this diagnosis and should not be deferred in an at-risk patient with a severe or atypical presentation."
  },
  {
   "title": "Treatment",
   "content": "First-line treatment for uncomplicated otitis externa (without abscess, osteitis, middle-ear disease, or recurrent infection) is topical otic preparations combining an antibiotic and a corticosteroid, such as polymyxin/neomycin or a fluoroquinolone otic drop, after gentle debridement of canal debris; systemic analgesia is also appropriate given the significant pain these infections cause. When canal edema is severe enough that topical drops cannot reach the more proximal canal, insert a wick to facilitate drug delivery \u2014 this may require ENT referral if the canal is too edematous to visualize the tympanic membrane. Systemic (oral) antibiotics, such as ciprofloxacin (covering Pseudomonas), are indicated for severe cases unresponsive to topical therapy or when cellulitis extends beyond the external canal. Recalcitrant cases, especially with prominent pruritus, should be evaluated for fungal disease (otomycosis) or a deeper infection. Persistent purulent otorrhea despite appropriate treatment should prompt staged escalation: refer to otolaryngology if drainage persists beyond 2 weeks despite oral and topical antibiotics; consider cholesteatoma if otorrhea persists beyond 6 weeks unresponsive to treatment; and consider MRSA as the most likely isolate if discharge persists beyond 3 months despite multiple courses of topical and oral antibiotics."
  }
 ],
 "clinical": [
  {
   "title": "Management at the bedside",
   "content": "Confirm the diagnosis using the 48-hour onset criterion plus tragal/auricular traction tenderness, and gently debride the canal both to confirm the diagnosis directly and to allow topical medication to reach the inflamed skin. Start first-line topical combination antibiotic-corticosteroid drops (polymyxin/neomycin or a fluoroquinolone) for uncomplicated cases, and add oral analgesia given how painful this condition typically is. If canal swelling is too severe for drops to penetrate proximally, place a wick \u2014 and refer to ENT if the swelling is severe enough that you cannot visualize the tympanic membrane, since these patients need specialist canal management and a temporary wick.\n\nEscalate to oral ciprofloxacin for cases not responding to topical therapy or when cellulitis has spread beyond the external canal, and evaluate for malignant otitis externa with imaging in any diabetic or immunosuppressed patient who has disproportionate pain, otorrhea, or new cranial nerve findings \u2014 do not manage this population with topical therapy alone. If drainage persists beyond 2 weeks despite appropriate treatment, refer to otolaryngology; if it persists beyond 6 weeks, evaluate for cholesteatoma; and if it persists beyond 3 months despite multiple antibiotic courses, consider MRSA as the likely organism and adjust antimicrobial coverage accordingly.\n\nFor prevention, counsel families to dry the ear canal after swimming, avoid cotton swabs and other objects that disrupt the protective cerumen layer or cause canal trauma, and consider drying drops (e.g., dilute acetic acid or alcohol-based solutions) for children with recurrent episodes, particularly frequent swimmers, since disruption of the natural cerumen barrier is the central mechanism driving this condition."
  }
 ]
}