Perichondritis of the auricle: bacterial findings and clinical evaluation of different antibiotic regimens.

PURPOSE: Pseudomonas aeruginosa is commonly found in suppurative perichondritis, but the significant pathogens in non-abscess perichondritis are unclarified. We aimed to explore the bacterial findings and evaluate the effectiveness of different antibiotic regimes in the treatment of patients with perichondritis.

METHODS: All patients treated for perichondritis at the two Ear-Nose-Throat Departments in Central Denmark Region (covering 20% of the Danish population) from January 1990 to October 2018 were included.

RESULTS: In total, 112 patients with (n = 12) or without (n = 100) abscess were included in the study. Potential pathogens were found in 40 of 55 cultures. P. aeruginosa was recovered in 58% of abscess cases, while Staphylococcus aureus was predominant in non-abscess infections (49%). Eighty-two percent of S. aureus recovered were isolated as heavy or moderate growth. In non-abscess cases, no significant differences in clinical progress (p = 0.65), alteration in antibiotic therapy (p = 0.31), duration of hospitalization (p = 0.65), or frequency of relapse of infection (p = 1.00) or sequelae (p = 0.38) were found between patients treated with antibiotics covering S. aureus vs. P. aeruginosa.

CONCLUSIONS: Our findings suggest that intravenous antibiotic therapy covering S. aureus is sufficient and appropriate empirical treatment in the majority of patients with non-abscess perichondritis. Antibiotic coverage should be expanded to include P. aeruginosa if the clinical response is disappointing or cultures grow P. aeruginosa. The risks and downsides to this approach seems limited as only a minority of patients suffered (minor) cosmetic sequelae and relapse of infection in our cohort of non-abscess perichondritis patients initially treated with antibiotics not covering P. aeruginosa.