Malignant otitis externa

Otomycosis: The foremost aetiological agent causing otitis externa and the antifungal susceptibility pattern in North-Western Iran

BACKGROUND

Otomycosis is considered a recurring fungal ear infection. The external auditory canal provides an appropriate and optimal situation for fungal growth.

OBJECTIVES

The study aimed to identify the causative agents of otomycosis and determine corresponding antifungal drug susceptibility patterns in north-western Iran.

METHODS

From October 2020 until November 2021, 200 patients attended an otolaryngology referral centre with otitis externa, and their ear discharge and debris were examined and cultured. The identification of the fungal agents was implemented by polymerase chain reaction-restriction fragment length polymorphism and sequencing. In vitro antifungal susceptibility testing of the isolates was conducted in accordance with the CLSI broth microdilution protocols.

RESULTS

The prevalence of otomycosis was measured 50.5% (n = 101/200). The majority of patients were in their forties (n = 35, 34.6%) and female (n = 57, 56.4%), and the most prevalent symptom was otalgia (56.4%). The most underlying factor was remarked manipulation employing a cotton swab (65.3%). Regarding fungus, Aspergillus section Nigri (58.57%) was the foremost isolate, followed by Aspergillus section Flavi (19.23%) and Candida parapsilosis (14.96%). The predominance of Aspergillus isolates had minimal in vitro sensitivity to tioconazole and nystatin. Candida species represented higher geometric mean minimum inhibitory concentrations (MIC) against nystatin. The MIC of three Aspergillus species isolates shown above the epidemiologic cut-off values (ECV) against itraconazole.

CONCLUSIONS

Otomycosis incidence surpassed in comparison with the previous study as the most common cause of otitis externa. The MIC distribution of Aspergillus species isolates against triazole antifungals is close to the defined ECVs and likely outrun it over time.

Malignant otitis external-our experience

Malignant external otitis is an extremly morbid ostomnyelits of external auditary canal, mastoid and skitil base caused by pseudomonas arergenosa. We report our experience with six cases, which we came across in ten years.Patitents' profile our management and results are presented. A need for increasing awareness tif the condition and the probability uj early diagnosis with a high index of suspicion in the early stages is discussed. Attempt also is done to review a few recent articles with special emphasis on imaging techniques and radioistope scans.

Otitis externa: clinical comparison of local ciprofloxacin versus local oxytetracycline, polymyxin B, hydrocortisone combination treatment

Thirty patients with otitis externa were included in a prospective, randomized, parallel group comparison study. Treatment regimens used were ciprofloxacin (2 mg/ml) as ear drops twice daily or drops containing oxytetracycline (5 mg/ml) polymyxin B (10,000 units/ml) and hydrocortisone (15 mg/ml) twice daily for 7 days. Evaluation was by clinical signs and symptoms and bacteriological findings from ear swabs prior to and 3 and 8 days after start of therapy, together with long-term follow-up if necessary. Sixteen patients were included in the ciprofloxacin and 14 in the combined antibiotic group. Six of 16 and 7 of 14 initial swabs, respectively, contained Pseudomonas aeruginosa. Mixed Gram-negative and Gram-positive pathogens were found in 3 patients in the ciprofloxacin group. All Gram-negative isolates were sensitive to ciprofloxacin. Microbiological evaluation showed rapid eradication of all bacterial pathogens in the ciprofloxacin group with 1 persistence of Candida albicans but eradication of Staphylococcus aureus in the same ear with marked clinical improvement. There was 1 case of supercolonization in the ciprofloxacin group with Candida parapsilosis. In the combined antibiotic group, there were 7 persistencies of which 5 were P. aeruginosa. No adverse effects were noted in either group. Treatment was assessed as a complete success in 14/16 and 5/14 cases, partial success in 2/16 and 4/14 cases and unsuccessful or indeterminate in 0/16 and 5/14 cases, respectively. Ciprofloxacin thus appears to be a useful and effective agent in the local therapy of otitis externa.

Carcinoma of temporal bone presenting as malignant otitis externa

A 69-year-old man presented with a three-month history of otalgia and tenderness of the right ear and a one-week history of a painful right parotid swelling. Examination revealed granulation tissue in the right ear canal with normal looking tympanic membranes and a parotid abscess. Repeated biopsies from the ear canal and parotid showed non-specific inflammation. Repeated cultures from both areas grew Ps. aeruginosa. The patient's condition improved following three weeks of intensive treatment for malignant otitis externa only to relapse five weeks after the end of treatment. He received a second course, only to improve temporarily. He developed a right facial nerve palsy five weeks after he was first seen, followed four months later by palsies of all cranial nerves except the olfactory, before dying, seven months after his first appointment. The radiological, histological and post-mortem findings are discussed.

Microbial aetiology of otitis externa

Microbiological samples were collected from the ears of patients with otitis externa for a period of 1 year. Altogether, 226 evaluable samples from 104 males and 122 females were received. The age range of the patients was similar to that of the Norwegian population. A wide variety of bacteria and fungi was isolated. The commonest isolates, excluding normal flora, were Staphylococcus aureus (34.1%), Pseudomonas aeruginosa (22.1%) and Streptococcus pyogenes (8.8%); 9.3% samples contained fungi. Of all samples, 15% showed a mixture of Gram-positive and Gram-negative, potentially pathogenic, bacteria. Infection due to Gram-negative organisms alone was commoner in males, while the lack of any obvious microbial aetiology was more frequent in females. Isolation of S. aureus together with S. pyogenes was common but that of S. aureus together with S. pyogenes was common but that of S. aureus together with P. aeruginosa was unusual. In treated patients, the finding of streptococci and S. aureus was rare whereas that of P. aeruginosa or absence of growth was common. Otitis externa involving Gram-positive bacteria seems to be more prevalent in our area than in that of other reported studies.

Malignant external otitis in an infant

Ten cases of malignant external otitis in children have been reported hitherto. These are reviewe, and an eleventh case, a three-month-old infant associated with genetic granulocytopenia, is presented. On the grounds of the reported paediatric cases, the erudition in childhood is compared with the more common form in the adult, and is found to be much less linked with diabetes mellitus and to have a far better prognosis, with practically no mortality.

‘ENT’ and eye infections

This chapter discusses ear, nose, throat, and eye infections. Many different bacterial species normally colonize the mouth. Host defense mechanisms, including those associated with the ciliated epithelium in the nose and sinuses, lysozyme in saliva, and IgA and other immunoglobulins in mucous secretions or serum, may help reduce the incidence of infections because of respiratory pathogens. The normal mouth flora probably contributes to the prevention of attachment of exogenous pathogens to the mucosa. Nevertheless, certain respiratory pathogens are sometimes carried asymptomatically in the mouth or nose of healthy individuals. Upper respiratory tract infections are extremely common in infants and young school children. An average preschool child is said to have about six upper respiratory tract infections a year. Most of the infections are of viral etiology and occur in winter. Bacterial infections are also very common in young children. The eustachian tubes in infants are relatively wider and more horizontal than in adults; this might partly explain the greater incidence of acute otitis media in infants as the causative organisms may spread directly from the throat to the middle ear via the eustachian tube. Older children and adults usually have good immunity to a wide range of respiratory pathogens, but the common cold continues to be prevalent in these age groups. Sinusitis frequently occurs in adults and children.