CSOM (Chronic suppurative otitis media) is a chronic infection of the ear with purulent discharge oozing from the ear in a patient with a perforated tympanic membrane. Although ear discharge that lasts longer than six weeks is typically considered chronic, the WHO defines CSOM as ear discharge that lasts longer than two weeks.

Risk Factors for CSOM:

Patients who have otitis media early in their childhood, those with recurrent attacks of otitis media and patients with chronic secretory otitis media are prone to develop CSOM. Other risk factors include:

• a low socioeconomic status,
• malnourished individuals,
• those with chronic diseases like diabetes, tuberculosis, HIV infections, and cancers
• Patients with craniofacial anomalies, cleft palate, ciliary disorders, and Down's syndrome
• Patients on long term immunosuppressants, chemotherapeutic agents, and hypo gamma/ agammaglobulinemia.

Early recognition and treatment are necessary because of the complications associated with the condition notably permanent hearing loss and cholesteatoma.

Treatment of CSOM:

The initial empiric therapy includes topical antibiotics and aural toilet. The aural toilet alone is not recommended. It results in a better antibiotic and antiseptic penetration and is therefore combined with topical antibiotics. The aural toilet is done to dry the ear and clear it of any debris. Techniques for the aural toilet include:

• Dry mopping with a wisp of cotton
• Ear wicking
• suctioning

Topical antibiotics should be preferred initially. These include topical ofloxacin and ciprofloxacin administered twice daily. Apart from the ofloxacin and ciprofloxacin, other agents like amoxicillin, antifungal agents, and aminoglycosides are not FDA-approved for topical use. Furthermore, other agents may be associated with greater toxicity and may be less effective. Topical antiseptic agents may be used only if gentle suctioning can not be done or is not available.

Topical antiseptics include: 

• Hydrogen peroxide
• Zinc
• Boric acid
• Acetic acid (vinegar), and
• Povidone-iodine (PVP-I)
• Burrow's solution (aluminum acetate) and vinegar (acetic acid) may be used in resource-limited settings.

Vinegar is effective in 60 - 80% of the cases of CSOM with persistent ear discharge, however, it is difficult to tolerate and may result in non-compliance.

Similarly, Povidone-iodine is thought to have similar efficacy as topical ciprofloxacin. Oral and intravenous antibiotics may be added if topical therapy fails and the patients have persistent ear discharge after 3 weeks of antibiotic therapy. Although, systemic antibiotics do not penetrate the infected area as the topical antibiotics do. However, if the culture and sensitivity results indicate the use of antibiotics other than topical ciprofloxacin and ofloxacin, systemic therapy may be indicated in such cases. Other indications may include sick patients, those with extensive disease, and immunocompromised patients. Options for systemic therapy may include imipenem, ceftazidime, aztreonam, and linezolid.

Patients who are not treated timely may develop complications like:

• Hearing loss
• Mastoiditis
• Subperiosteal abscess
• Labyrinthitis
• facial palsy
• Meningitis
• Lateral sinus thrombosis
• Brain abscess

Last but not least, comorbid conditions should be treated. Specifically, poorly controlled diabetes should be treated and infectious disease consultations should be taken from the experts.

A Case Scenario of CSOM and poorly controlled Diabetes Mellitus

A 58 years of age, female patient presented with vertigo for the past two weeks. She also complained of purulent discharge from the left ear along with a low-grade fever and headache. There was no history of focal weakness or sensory symptoms, seizures, bladder or bowel-related symptoms. She is a diagnosed case of type 2 diabetes mellitus and currently on premixed insulin (Humulin 70/30) 44 units in the morning and 32 units in the evening. She recently consulted an ENT specialist and was prescribed the following medications:

• Ranitidine 150 mg twice daily
• Betahistine 8 mg thrice daily
• vitamin B 12
• Humulin 70/30 (44 units before breakfast and 32 units before dinner)
• Metformin 1000 mg twice daily
• Cefuroxime (Zinacef) 250 mg two times per day

On examination, she was well oriented but could not sit comfortably because of severe vertigo. She had horizontal nystagmus but the rest of the neurological examination was unremarkable. She had a cotton bud in her ear which was soaked with serous fluid. Systemic examination was unremarkable.

Her blood sugars at the time of the examination were 450 mg/dl.

She was advised culture and sensitivity test along with KOH stain and fungal culture of the fluid draining from the ear and a CECT of the head/ brain. She was also advised to revisit her ENT specialist as she was still symptomatic after one week of cefuroxime axetil (Zinacef). Her antidiabetic medicines were modified:

• Sitagliptin and metformin 50/1000 mg twice daily
• Inj. Aspart 28 units before breakfast and lunch
• Inj. Ryzodeg (Aspart and Degludeg) 36 units before dinner

The dose of Betahistine was enhanced to 16 mg thrice per day. Her blood sugar record after one week was slightly above the ranges for which the dose was adjusted. CECT brain and the fungal stains/ culture and sensitivity results are awaited.

In conclusion,

CSOM is a chronic infection of the middle ear manifesting as ear discharge and perforated tympanic membrane. Prolonged topical antibiotic therapy along with aural toilet is necessary to avoid long--term complications. Comorbid conditions especially diabetes should be managed appropriately to achieve better results.