Abstract
Otitis externa is an inflammatory condition of the external auditory canal which occurs due to any trauma, changes in the PH of the skin of external auditory canal. The normal PH of the external auditory canal skin should be in the acidic medium. This inhibits the growth of certain infectious microorganisms. Once the external canal skin PH becomes alkaline, the chances of inflammation of the skin increases. To assess the pH of the external auditory canal in cases of otitis externa with secretion and compare the treatment efficacy of treating it with topical anti-inflammatory like ichthammol glycerine, topical steroid cream and oral antibiotics. A prospective observational study involved a total of 120 patients who came with symptoms and signs of external otitis. pH of external canal was measured during first visit and at 42 days. The patients were divided into three groups. First group was treated with Ichthammol glycerine, second group was treated with Ichthammol glycerine with topical steroid cream and third group was treated with oral antibiotics with topical steroid cream. Patients were analyzed based on severity score during first visit, at 7 days, at 21 days and 42 days. This study involved 64(53.3%) patients were male and 56(46.7%) were females. The mean age group involved in the study was 42.50 years. The mean PH value in the external auditory canal during the first visit was alkaline (6.09) and the mean PH value at 42 days was changed to acidic (4.95) which was statistically significant (p = 0.00). There was significant reduction in the severity score in the oral antibiotic with topical steroid cream, followed by IG with topical steroid cream followed by Ichthammol glycerine (p = 0.001). In this study we have analyzed the pH level favorable in causing otitis externa and the best available treatment for the same. It has been observed that the alkaline Ph is more favorable in causing otitis externa. Efficacy of Topical corticosteroid with antibiotics is maximum in the management of otitis externa.
Keywords: pH, External auditory canal, Skin, Otitis externa, Eac skin PH
Introduction
Otitis externa is the condition was first described by Mayer in 1844, there are extensive research in this field and in the otorhinolaryngology practice, there are considerable amount of patients with otitis externa are encountered [1–6]. Even though otitis externa is acute, there are many chances to become chronic [1]. McLaurin et al. [7] defined the condition chronic otitis externa in 1964 as a recurrent or persistent infection caused by two factors: one is continuity of the epithelium was disturbed and the second one is change of H of skin of external canal from acidic to alkaline medium.
External canal skin act as a barrier against exogenous trauma and the another function is bactericidal and fungicidal which was achieved by acidity of skin of external canal [1]. March ionini and Hausknetch postulated that ‘acid cloak’ is present in the skin of external canal and Wise and Sulzberger suggested that acidification of the skin surface helps to manage the skin conditions [8, 9]. Blank conducted a study on measurement of PH of skin on adults and children and found PH ranges from 4.2 to 5.6, in female 0.5 units higher compared to males [10]. Bernstein and Hermann performed the study of PH in eczematous skin conditions and concluded that alkaline medium was higher in the fissures of the skin [11].
In 1949, Fabricant and Perlstein were the first otologists studied about the skin pH of the external auditory canal in normal individuals [12]. Later on, in 1957, Fabricant compared the previous study findings with the pH of the patients with acute otitis externa, and concluded that higher pH was seen in otitis externa [13].
The objective of the study was to assess the pH of the skin of the external canal in patients with otitis externa with secretion and compare the treatment efficacy of treating it with topical anti inflammatory like ichthammol glycerine, topical steroid cream and oral antibiotics.
Methodology
Sample size—120 (Using EPI info software).
Sample size formula—S = 2 * p * 1 − p/d2.
Study design—A prospective observational study.
Study area—Department of Otorhinolaryngology (ENT), Chettinad hospital & research institute.
Duration of the study—The study was conducted between 20th December 2020 and 21st December 2021.
After taking detailed history in patients with otitis externa, the patients undergone thorough otorhinolaryngological examination and systemic examination. This was followed by the measurement of the pH of the external auditory canal by placing the pH strips in the outer third of the discharge in the external auditory canal and check for colour change (Fig. 1). Patients were divided into three groups based on the treatment. One group was treated with Icthamol glycerol, other group was treated with Icthamol glycerol with topical steroid cream and one more group was treated with oral antibiotics with topical steroid cream.
Fig. 1.
Measurement of external canal PH using PH strips
Inclusion Criteria
All patients who had attended the ENT Outpatient department/Inpatient department with clinical features related to otitis externa will be included in the study.
Patients of both sexes.
Patients of all age group.
Diagnostic criteria of otitis externa are sudden onset of symptoms such as ear pain, aural fullness, ear itching and signs such as skin edema, congestion, or ear discharge with tragal tenderness
Exclusion Criteria
Cases of acute suppurative otitis media (ASOM) and chronic suppurative otitis media (CSOM), furunculosis, malignant otitis externa, skin conditions like contact dermatitis, psoriasis
Systemic diseases like diabetes, immunodeficiency and patients on immunosuppressive drugs/cancer chemotherapy were excluded from the study.
Around 120 patients fulfilling the inclusion and exclusion criteria, diagnosed to have acute otitis externa were included in the study. The patients were divided into groups randomly, one group was Ichthammol glycerine application, topical steroid cream with Ichthammol glycerine application and with Systemic antibiotics and topical steroid cream.
Treatment and Randomisation
Randomization was done by computer generated randomisation list, with a ratio of 1:3. Overall, 120 patients were randomised to three groups. One group received three ear drops three times daily of either (Ichthammol glycerine application; n = 40), (topical steroid cream with Ichthammol glycerine application group; n = 37), or (Systemic antibiotics and topical steroid cream; n = 43). The ear drops, ichthammol glycerine paint and tablets were administered in a double blind fashion, according to the randomisation list.
Measurements
At the baseline visit the doctor recorded the severity score based on the symptoms and sings (none, moderate, severe) the signs in the external auditory canal and auricle and condition of tympanic membrane.
The pH of the external auditory canal skin was assessed using a pH paper and placing it over the cartilaginous part during the first visit and at 42 days. The values were interpreted based on the colour reading in the pH strips (Fig. 2). A compressed dry wick was used to allow penetration of the drug along its length. After 24 h the wick was removed and the ear inspected. This was continued until the eardrum was visible and the drugs could penetrate the canal.
Fig. 2.
External auditory canal skin PH showing acidic and alkaline PH
The patient was asked to give information on risk factors (swimming, ear cleaning or picking, and use of hearing aids, earplugs, or personal stereo more than three times a week), antibiotic use in the past month, and the number of ear infections within the past year.
The first follow up visit was seven days after the baseline visit. If the patient had not recovered, treatment was continued, with a second follow up visit at 7 days and third follow up visit at 21 days. Patients who had not recovered continued treatment until 42 days, after which they were considered treatment failures if they had not recovered or they had been given an alternative treatment during the study period. At each follow up, the doctor determined treatment compliance from the amount of drug remaining and whether the patient had recovered.
Statistical Analysis
Statistical analysis was carried out using Statistical Package for the Social Sciences (SPSS) version 26.0 and Microsoft Excel software. The frequency and discriptions were used. The association between two groups were assessed by paired sample and Anova test. The statistical significance was considered when p value < 0.05.
Results
This study included a total of 120 patients among them 64(53.3%) patients were male and 56(46.7%) were females. The mean age group involved in the study was 42.50 years (Table 1). The mean PH value in the external auditory canal during the first visit was alkaline (6.09) and the mean PH value at 42 days was changed to acidic (4.95) which was statistically significant (p = 0.00) (Table.2).
Table 1.
Distribution of sex and age (N = 120)
| Sex | |
|---|---|
| S. no | N (%) |
| Male | 64 (53.3%) |
| Female | 56 (46.7%) |
| Age | ||
|---|---|---|
| Minimum | Maximum | Mean (Standard deviation) |
| 5 years | 82 years | 42.50 (18.86) |
Table 2.
PH value of external auditory canal
| S. no | PH of external auditory canal | Mean (SD) | t Value | P value |
|---|---|---|---|---|
| 1 | At presentation | 6.09 (0.56) | 18.44 | 0.00 |
| 2 | At 42 days | 4.95 (0.36) | 7 |
During the first visit, the severity of signs and symptoms were recorded in each group and considered as baseline for assessing the recovery in further visits. At first visit, the mean value of the signs and symptoms of the patients in Icthamol glycerol was 2.18, IG with topical steroid cream was 2.34 and oral antibiotic with topical steroid cream was 2.44. During second visit, at 7 days, the score in Icthamol glycereine was 1.93, IG with topical antibiotic cream was 1.73 and oral antibiotic with topical antibiotic cream was 1.51 which was statistically significant (p = 0.002). At 21 days, the score in Icthamol glycereine was 1.68, IG with topical antibiotic cream was 1.14 and oral antibiotic with topical antibiotic cream was 1.02 which was statistically significant (p = 0.00). At 42 days, the score in Icthamol glycereine was 1.15, IG with topical antibiotic cream was 1.0 and oral antibiotic with topical antibiotic cream was 1.0 which was statistically significant (p = 0.001). There was significant reduction in the severity score in the oral antibiotic with topical steroid cream, followed by IG with topical steroid cream followed by Ictahmol glycerol (Table 3).
Table 3.
Various treatment and their outcome
| S. no | Visit | Treatment | Mean (SD) | F value | P value |
|---|---|---|---|---|---|
| 1 | At presentation | Icthamol Glycerol | 2.18 (0.38) | 3.57 | 0.031 |
| IG with topical steroid cream | 2.35 (0.48) | ||||
| Oral antibiotic with topical steroid cream | 2.44 (0.50) | ||||
| 2 | 7 days | Icthamol Glycerol | 1.93 (0.47) | 6.739 | 0.002 |
| IG with topical steroid cream | 1.73 (0.56) | ||||
| Oral antibiotic with topical steroid cream | 1.51 (0.51) | ||||
| 3 | 21 days | Icthamol Glycerol | 1.68 (1.68) | 40.932 | 0.000 |
| IG with topical steroid cream | 1.14 (1.14) | ||||
| Oral antibiotic with topical steroid cream | 1.02 (1.02) | ||||
| 4 | 42 days | Icthamol Glycerol | 1.15 (0.36) | 6.882 | 0.001 |
| IG with topical steroid cream | 1.0 (0.0) | ||||
| Oral antibiotic with topical steroid cream | 1.0 (0.0) |
Discussion
Acute otitis externa is the inflammation of external auditory canal characterized by redness or swelling of the external auditory canal filled with debris associated with pain, itching, conductive hearing loss with the duration of less than 3 weeks (Fig. 3) [14]. The normal PH of the external auditory canal skin is acidic ranges from 4.2 to 5.6 [1]. During otitis externa, the PH of the canal changed from acidic to alkaline make its more prone to infection. There are various methods of treatment for otitis externa. The most commonly practiced management protocol includes debridement, acidifying antimicrobial agents with or without corticosteroids [15].The current study was aimed to assess the pH of the external auditory canal in cases of otitis externa with secretion and compare the treatment efficacy of treating it with topical anti-inflammatory like ichthammol glycerine, topical steroid cream and oral antibiotics. This study included a total of 120 patients among them 64(53.3%) patients were male and 56(46.7%) were females. The mean age group involved in the study was 42.50 years. The mean PH value in the external auditory canal during the first visit was alkaline (6.09) and the mean PH value at 42 days was changed to acidic (4.95) which was statistically significant (p = 0.00).
Fig. 3.
External canal showing features of otitis externa
At first visit, the mean value of the signs and symptoms of the patients in Icthamol glycerol was 2.18, IG with topical steroid cream was 2.34 and oral antibiotic with topical steroid cream was 2.44. At 7 days (p = 0.002) and 21 days (p = 0.00) the symptoms and signs were highly improved in the topical steroid cream with oral antibiotics followed by topical steroid cream with icthamol glycerol followed icthamol glycerol alone. At 42 days, the score in Icthamol glycereine was 1.15, IG with topical antibiotic cream was 1.0 and oral antibiotic with topical antibiotic cream was 1.0 which was statistically significant (p = 0.001). There was significant reduction in the severity score in the oral antibiotic with topical steroid cream, followed by IG with topical steroid cream followed by Ictahmol glycerol.
Van Balen et al. [14] compared the three common treatment in otitis externa: Acetic acid alone, acetic acid with steroid and steroid with antibiotics and concluded Steroid and acetic acid or steroid and antibiotic ear drops are equally effective.
Kim et al. [16] measured PH of external auditory canal during otitis externa and compared vinegar irrigation with topical antibiotics and found that the EAC lost its acidity proportionately to the degree of disease in otitis externa and Vinegar irrigation and topical antibiotics were equally effective for restoration of pH.
Martinez-Devesa et al. [1] compared PH of external auditory canal in normal people and the patients with otitis externa and concluded that alkaline PH in the skin of ear canal was more prone for progression to chronic otitis externa especially in the younger individual.
Mittal A et al. [17] compared EAC PH of normal individual with otitis externa, its variation in change of temperature and humidity and found that acidification of the EAC is the only treatment required in most cases. No significant change in pH of ears was observed with changes of temperatures and humidity.
Conclusion
In this study we have analyzed the pH level favorable in causing otitis externa and the best available treatment for the same
It has been observed that the alkaline Ph is more favorable in causing otitis externa.
Efficacy of Topical corticosteroid with antibiotics is maximum in the treatment of otitis externa.
Funding
This study did not receive any kind of funding from any sources.
Data Availability
The collected data will be kept confidential. All routine investigation will be done as per standard protocol.
Declarations
Conflict of interest
The authors express no conflict of interest.
Ethical Approval
The study will be conducted only after obtaining approval by the Institutional Human Ethics Committee.
Consent to Participate
All patients will be treated equally irrespective of their participation in the study. The cost of any investigations required for the study will be borne by the chief investigator.
Informed Consent
Informed consent will be obtained from all the patients who participate in the study.
Footnotes
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Associated Data
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Data Availability Statement
The collected data will be kept confidential. All routine investigation will be done as per standard protocol.