The significance of tissue biopsy for fungi in necrotizing otitis externa

The conventional treatment for necrotizing otitis externa (NOE) is prolonged anti-pseudomonas therapy, with surgical treatment in non-responsive patients. The aim of the present study is to describe the course of management of patients with non-responsive NOE undergoing hyperbaric oxygen therapy (HBOT), and to investigate the importance of tissue biopsy for fungi in this group of patients.

A retrospective study conducted between January 2010 and December 2013 at an Otolaryngology Head and Neck Surgery Department. Included were all 52 patients with NOE referred to our Medical Centre for further treatment including HBOT.

Fifty-two consecutive patients, 29 men and 23 women, with a mean age of 70.6 years, were included in our study. Twenty seven (51.9%) underwent surgical debridement. No significant difference was found between the group having surgical intervention, and those who did not, with regard to sex, age, comorbidities, cranial nerve involvement or laboratory results. However, those who had surgical intervention had a statistically significant higher rate of fungal infection (P = 0.049). After completing 7 weeks of HBOT, a significantly lower WBC count was observed in the fungus-infected group (7000 vs 7.800, P = 0.03), and a tendency towards lower CRP levels in the fungus-infected group (16 vs 58, P = 0.087).

Patients with NOE should have a comprehensive surgical intervention when delayed healing is observed, because proper fungal culturing might change the course of treatment and improve prognosis.

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