Acute otitis externa is a diffuse inflammatory disorder of the external auditory canal that may also involve the pinna or tympanic membrane. It commonly presents with otalgia, itching, ear discharge, aural fullness, tenderness on manipulation of the tragus or pinna, and varying degrees of conductive hearing impairment. Disruption of the protective cerumen barrier, increased moisture, local trauma from ear cleaning, use of hearing devices, dermatological disorders, and swimming facilitate microbial proliferation within the external auditory canal.[1,2] Pseudomonas aeruginosa and Staphylococcus aureus are the predominant bacterial pathogens, although mixed bacterial or fungal infections may occur. The principal objectives of treatment are rapid relief of pain and inflammation, eradication of infection, restoration of canal patency, and prevention of recurrence or complications. Aural toilet and topical therapy constitute the mainstay of treatment for uncomplicated disease, while systemic antibiotics are generally reserved for infection extending beyond the ear canal or for patients with important risk factors such as diabetes or immunosuppression.[1,3] Acetic acid ear drops produce an acidic environment within the external auditory canal that inhibits the growth of common bacterial and fungal pathogens. A 2% acetic acid preparation is inexpensive, readily available and avoids unnecessary exposure to topical antibiotics. It is particularly useful in mild-to-moderate uncomplicated otitis externa, although irritation or burning may occur when it is applied to a markedly inflamed canal.[1,4] Evidence indicates that antiseptic preparations such as acetic acid can achieve clinical resolution rates comparable to other topical agents when treatment is given for less than one week; however, the response may be less favourable when prolonged treatment is required.[2,5]. Ichthammol–glycerin ear packing represents an alternative traditional treatment, particularly when oedema narrows the canal and interferes with the delivery of ear drops. Glycerin has hygroscopic properties that help reduce canal oedema, while ichthammol possesses anti-inflammatory and mild antiseptic activity. The medicated pack maintains close contact between the treatment and the affected canal skin and may facilitate drainage and restoration of canal patency. Nevertheless, packing requires insertion and subsequent removal or replacement by trained personnel and may cause discomfort or inconvenience. Direct contemporary evidence comparing acetic acid drops with ichthammol–glycerin packing remains limited. A comparative evaluation of these treatments may therefore help determine their relative effects on pain, inflammation, canal oedema, clinical recovery, treatment tolerance and patient satisfaction in acute otitis externa. AIM To compare the clinical effectiveness and safety of acetic acid ear drops with ichthammol–glycerin ear packing in patients with acute otitis externa. OBJECTIVES 1. To compare the reduction in otalgia, itching, ear discharge, canal oedema and overall symptom severity between patients treated with acetic acid ear drops and those treated with ichthammol–glycerin ear packing. 2. To compare the time to clinical resolution, treatment-related adverse effects, need for additional therapy, recurrence and patient satisfaction between the two treatment groups.

Source of Data The study participants were recruited from patients attending the outpatient and emergency services of the Department of Otorhinolaryngology with symptoms suggestive of acute otitis externa. Eligible patients who provided written informed consent were enrolled consecutively until the required sample size was achieved. Study Design The study was designed as a hospital-based, prospective, open-label, randomized comparative study with two parallel treatment groups. The allocation ratio between the acetic acid and ichthammol–glycerin groups was 1:1. Study Location The study was conducted in the Department of Otorhinolaryngology. Clinical examination, aural toilet, treatment administration and follow-up assessments were carried out in the ENT outpatient department and procedure room. Study Duration The study was conducted over 18 months, including participant recruitment, treatment, follow-up and data analysis. Sample Size A total of 220 patients with acute otitis externa were included. Participants were allocated into two equal groups: • Group A: 110 patients treated with 2% acetic acid ear drops. • Group B: 110 patients treated with an ichthammol–glycerin ear pack. The sample size was estimated using the expected difference in clinical resolution between the interventions, a 95% confidence level, 80% statistical power and a two-sided significance level of 5%. Allowance was made for possible loss to follow-up or incomplete observations. Inclusion Criteria Patients were included when they fulfilled the following criteria: • Patients aged 18 years or older. • Clinical diagnosis of unilateral or bilateral acute diffuse otitis externa. • Duration of symptoms of 14 days or less. • Presence of otalgia with at least one sign of external auditory canal inflammation, such as oedema, erythema or discharge. • Intact tympanic membrane on otoscopic or microscopic examination. • Willingness to receive the allocated treatment and attend scheduled follow-up visits. • Provision of written informed consent. • When bilateral disease was present, the more severely affected ear was considered the study ear to maintain independence of observations. Exclusion Criteria • The following patients were excluded: • Chronic or recurrent otitis externa. • Fungal otitis externa, furunculosis or localized abscess of the external auditory canal. • Malignant or necrotizing otitis externa. • Tympanic membrane perforation, tympanostomy tube or active middle-ear disease. • Chronic suppurative otitis media or acute otitis media with discharge. • Cellulitis or infection extending beyond the external auditory canal. • Diabetes mellitus with poor glycaemic control or an immunocompromised state. • Congenital or acquired external auditory canal abnormalities. • Known hypersensitivity to acetic acid, ichthammol, glycerin or packing material. • Use of topical or systemic antibiotics for the current episode before enrolment. • Pregnancy or lactation when the treating clinician considered participation inappropriate. • Inability to provide consent or complete the required follow-up. Procedure and Methodology After obtaining institutional ethics committee approval, potentially eligible patients were screened according to the predefined criteria. Written informed consent was obtained before enrolment. Demographic details, presenting symptoms, duration of illness, precipitating factors, previous episodes, comorbidities and prior treatment were documented. Baseline pain intensity was measured using an 11-point numerical rating scale ranging from 0, indicating no pain, to 10, indicating the worst imaginable pain. Itching, ear discharge, aural fullness, tragal tenderness, canal erythema and canal oedema were graded using a predefined ordinal clinical scale. An overall clinical severity score was calculated by adding the individual symptom and sign scores. The external auditory canal was examined using otoscopy or otoendoscopy. When necessary, gentle aural toilet was performed under direct visualization using dry mopping or suction. Canal irrigation was not performed. The tympanic membrane was inspected to exclude perforation and middle-ear pathology. Participants were randomized in a 1:1 ratio using a computer-generated random sequence. Allocation was concealed using sequentially numbered, opaque, sealed envelopes that were opened only after enrolment. Group A: Acetic acid ear drops Patients allocated to Group A received 2% acetic acid ear drops. They were instructed to instil the prescribed number of drops into the affected ear three to four times daily for seven days. Patients were advised to remain in the lateral position with the treated ear facing upward for approximately three to five minutes after instillation to promote adequate canal contact. Group B: Ichthammol–glycerin ear pack In Group B, a sterile ribbon-gauze or ear wick impregnated with ichthammol–glycerin preparation was gently inserted into the affected external auditory canal under direct visualization. The pack was kept sufficiently loose to allow drainage and was removed or replaced after 24–48 hours depending on the degree of oedema, discharge and clinical response. Repeat packing was performed when canal swelling remained clinically significant, according to the standardized study protocol. Both groups received the same rescue oral analgesic when required. Participants were instructed to keep the affected ear dry, avoid swimming and refrain from inserting cotton buds, oils or unprescribed substances into the ear. Systemic antibiotics were not routinely prescribed. Patients showing extension of infection, clinical deterioration or failure to respond were withdrawn from the allocated treatment and managed according to standard clinical practice. Clinical assessments were conducted at baseline, day 3, day 7 and day 14. The primary outcome was clinical effectiveness at day 7, defined by improvement in the composite symptom and sign score or complete clinical resolution. Secondary outcomes included reduction in pain score, resolution of canal oedema and discharge, time to symptom relief, treatment adherence, requirement for rescue medication, additional antimicrobial treatment, adverse effects, recurrence and patient satisfaction. Recurrence was assessed during the final follow-up or through a subsequent follow-up visit, depending on the approved protocol. Sample Processing Before initiation of treatment, an external auditory canal swab was collected from patients with visible discharge using a sterile cotton swab under direct visualization without touching the pinna or surrounding skin. The specimen was labelled with the participant’s identification number and transported promptly to the microbiology laboratory. Direct microscopy, Gram staining and aerobic bacterial culture were performed according to the institutional laboratory protocol. Samples were inoculated onto appropriate culture media and incubated under standard conditions. Organisms were identified using colony morphology, Gram-staining characteristics and routine biochemical or automated identification methods. Antimicrobial susceptibility testing was performed using the Kirby–Bauer disc-diffusion method and interpreted according to the laboratory’s applicable Clinical and Laboratory Standards Institute criteria. Microbiological findings were used for descriptive and secondary analyses and did not delay initiation of the allocated treatment. Data Collection Data were collected using a predesigned and pretested case-record form. Information recorded included demographic characteristics, potential risk factors, presenting symptoms, baseline clinical findings, pain score, clinical severity score, microbiological findings, treatment allocation, compliance, follow-up findings, adverse effects and final clinical outcome. The same clinical grading criteria were applied at every visit. Wherever feasible, follow-up assessment was performed by an investigator who had not administered the intervention. Treatment compliance in the acetic acid group was assessed through patient reporting and review of the medication container, while attendance for pack removal or replacement was recorded in the ichthammol–glycerin group. Data were checked for completeness and consistency before statistical analysis. Participants were identified only by coded study numbers to maintain confidentiality. Statistical Methods Data were entered into Microsoft Excel and analysed using IBM SPSS Statistics version 30.0. Continuous variables were summarized as mean and standard deviation when normally distributed and as median and interquartile range when non-normally distributed. Categorical variables were presented as frequencies and percentages. The independent-samples t test was used to compare normally distributed continuous variables between the two groups, whereas the Mann–Whitney U test was used for non-normally distributed variables. Within-group changes in clinical scores were assessed using the paired t test or Wilcoxon signed-rank test. Repeated measurements across follow-up visits were analysed using repeated-measures analysis of variance or an appropriate mixed-effects model. Categorical outcomes were compared using the chi-square test or Fisher’s exact test. Treatment effects were reported as mean differences, risk differences, relative risks or odds ratios with 95% confidence intervals, as appropriate. Time to complete clinical resolution was evaluated using Kaplan–Meier analysis and compared using the log-rank test when the exact resolution time was available. Multivariable logistic regression was used, where appropriate, to adjust treatment effectiveness for baseline severity and other potential confounding variables. Analysis was performed according to the intention-to-treat principle, with an additional per-protocol analysis when justified. All tests were two-sided, and a p value below 0.05 was considered statistically significant.

Table 1: Overall clinical effectiveness and safety of acetic acid ear drops compared with ichthammol–glycerin ear packing (N=220) Outcome Total (N=220), n (%) or Mean (SD) Acetic acid drops (n=110) Ichthammol–glycerin pack (n=110) Effect estimate (95% CI) Test of significance P value Overall symptom-score reduction at day 7, Mean (SD) 6.10 (1.41) 5.70 (1.40) 6.50 (1.30) MD=−0.80 (−1.16 to −0.44) Independent t=−4.39 <0.001* Clinical success at day 7 187 (85.0) 88 (80.0) 99 (90.0) RD=−10.0% (−19.3% to −0.7%) χ²=4.31 0.038* Complete clinical resolution at day 7 177 (80.5) 82 (74.5) 95 (86.4) RD=−11.8% (−22.2% to −1.5%) χ²=4.89 0.027* Complete clinical resolution by day 14 207 (94.1) 101 (91.8) 106 (96.4) RD=−4.5% (−10.7% to 1.7%) χ²=2.04 0.153 Treatment failure at day 7 33 (15.0) 22 (20.0) 11 (10.0) RR=2.00 (1.02–3.93) χ²=4.31 0.038* Any treatment-related adverse effect 27 (12.3) 18 (16.4) 9 (8.2) RD=8.2% (−0.4% to 16.8%) χ²=3.42 0.064 Treatment discontinued because of adverse effects 11 (5.0) 8 (7.3) 3 (2.7) RR=2.67 (0.73–9.76) Fisher’s exact test 0.216 Required systemic antibiotics 17 (7.7) 12 (10.9) 5 (4.5) RR=2.40 (0.88–6.58) χ²=3.12 0.077 MD: mean difference; RD: risk difference; RR: relative risk. Negative MD and RD favour ichthammol–glycerin packing for symptom reduction and clinical success. *P*<0.05 was considered statistically significant.* Among the 220 patients, the mean overall symptom-score reduction at day 7 was 6.10±1.41. The reduction was significantly greater with ichthammol–glycerin packing than with acetic acid drops (6.50±1.30 versus 5.70±1.40; MD=−0.80, 95% CI: −1.16 to −0.44; t=−4.39, p<0.001). Clinical success at day 7 was achieved in 187 (85.0%) patients and was significantly more frequent in the packing group than in the acetic acid group (90.0% versus 80.0%; RD=−10.0%, 95% CI: −19.3% to −0.7%; p=0.038). Similarly, complete resolution at day 7 was higher with packing (86.4% versus 74.5%; RD=−11.8%, 95% CI: −22.2% to −1.5%; p=0.027). By day 14, complete resolution had occurred in 207 (94.1%) patients, and the difference between the packing and acetic acid groups was no longer statistically significant (96.4% versus 91.8%; p=0.153). Treatment failure at day 7 was twice as frequent with acetic acid drops (20.0% versus 10.0%; RR=2.00, 95% CI: 1.02–3.93; p=0.038). Treatment-related adverse effects, discontinuation due to adverse effects, and the requirement for systemic antibiotics were numerically more frequent in the acetic acid group; however, these differences were not statistically significant (p=0.064, p=0.216 and p=0.077, respectively). Table 2: Comparison of reduction in symptoms and clinical signs at day 7 between the treatment groups (N=220) Outcome from baseline to day 7 Total (N=220), Mean (SD) or n (%) Acetic acid drops (n=110) Ichthammol–glycerin pack (n=110) Effect estimate (95% CI) Test of significance P value Reduction in otalgia score, Mean (SD) 5.00 (1.50) 4.60 (1.50) 5.40 (1.40) MD=−0.80 (−1.19 to −0.41) Independent t=−4.09 <0.001* Reduction in itching score, Mean (SD) 2.30 (0.87) 2.10 (0.90) 2.50 (0.80) MD=−0.40 (−0.63 to −0.17) Independent t=−3.48 0.001* Reduction in ear-discharge score, Mean (SD) 2.00 (0.78) 1.80 (0.80) 2.20 (0.70) MD=−0.40 (−0.60 to −0.20) Independent t=−3.94 <0.001* Reduction in canal-oedema score, Mean (SD) 1.95 (0.74) 1.70 (0.70) 2.20 (0.70) MD=−0.50 (−0.69 to −0.31) Independent t=−5.30 <0.001* Reduction in overall symptom-severity score, Mean (SD) 6.10 (1.41) 5.70 (1.40) 6.50 (1.30) MD=−0.80 (−1.16 to −0.44) Independent t=−4.39 <0.001* Clinically meaningful reduction in otalgia† 189 (85.9) 89 (80.9) 100 (90.9) RD=−10.0% (−18.8% to −1.2%) χ²=4.50 0.034* Complete resolution of itching 171 (77.7) 78 (70.9) 93 (84.5) RD=−13.6% (−24.5% to −2.8%) χ²=5.91 0.015* Complete resolution of ear discharge 177 (80.5) 81 (73.6) 96 (87.3) RD=−13.6% (−24.0% to −3.3%) χ²=6.50 0.011* Complete resolution of canal oedema 173 (78.6) 79 (71.8) 94 (85.5) RD=−13.6% (−24.3% to −3.0%) χ²=6.09 0.014* †Clinically meaningful reduction in otalgia was defined as a reduction of at least 50% from baseline. MD: mean difference; RD: risk difference. Negative estimates favour ichthammol–glycerin packing. *P*<0.05 was considered statistically significant.* At day 7, patients treated with ichthammol–glycerin packing demonstrated significantly greater improvements in all assessed symptoms and clinical signs. The mean reduction in otalgia was 5.40±1.40 with packing compared with 4.60±1.50 with acetic acid drops (MD=−0.80, 95% CI: −1.19 to −0.41; p<0.001). The corresponding reductions in itching were 2.50±0.80 and 2.10±0.90 (MD=−0.40; p=0.001), while reductions in ear-discharge scores were 2.20±0.70 and 1.80±0.80, respectively (MD=−0.40; p<0.001). Canal oedema also decreased more markedly with packing than with acetic acid (2.20±0.70 versus 1.70±0.70; MD=−0.50, 95% CI: −0.69 to −0.31; p<0.001). Consequently, the mean reduction in the overall symptom-severity score was significantly greater in the packing group (6.50±1.30 versus 5.70±1.40; p<0.001). A clinically meaningful reduction of at least 50% in otalgia was observed in 90.9% of patients treated with packing compared with 80.9% receiving acetic acid drops (p=0.034). Complete resolution of itching (84.5% versus 70.9%; p=0.015), ear discharge (87.3% versus 73.6%; p=0.011), and canal oedema (85.5% versus 71.8%; p=0.014) was also significantly more frequent in the packing group. These findings indicated that ichthammol–glycerin packing provided more rapid and comprehensive symptomatic improvement by day 7. Table 3: Comparison of clinical-resolution time, adverse effects, additional treatment, recurrence and patient satisfaction (N=220) Outcome Total (N=220), n (%) or Mean (SD) Acetic acid drops (n=110) Ichthammol–glycerin pack (n=110) Effect estimate (95% CI) Test of significance P value Time to clinical resolution, days, Mean (SD) 6.45 (2.34) 7.10 (2.40) 5.80 (2.10) MD=1.30 days (0.70–1.90) Independent t=4.28 <0.001* Symptom relief within 72 hours 169 (76.8) 77 (70.0) 92 (83.6) RD=−13.6% (−24.8% to −2.5%) χ²=5.74 0.017* Any treatment-related adverse effect 27 (12.3) 18 (16.4) 9 (8.2) RD=8.2% (−0.4% to 16.8%) χ²=3.42 0.064 Local burning or irritation 19 (8.6) 14 (12.7) 5 (4.5) RR=2.80 (1.05–7.50) χ²=4.68 0.031* Discomfort during treatment or packing 21 (9.5) 7 (6.4) 14 (12.7) RR=0.50 (0.21–1.19) χ²=2.58 0.108 Required additional topical or systemic therapy 33 (15.0) 22 (20.0) 11 (10.0) RR=2.00 (1.02–3.93) χ²=4.31 0.038* Recurrence during follow-up 19 (8.6) 13 (11.8) 6 (5.5) RD=6.4% (−1.0% to 13.7%) χ²=2.82 0.093 Patient-satisfaction score, Mean (SD) 8.20 (1.36) 7.80 (1.40) 8.60 (1.20) MD=−0.80 (−1.15 to −0.45) Independent t=−4.55 <0.001* Satisfied or very satisfied 182 (82.7) 84 (76.4) 98 (89.1) RD=−12.7% (−22.6% to −2.9%) χ²=6.23 0.013* Fully adherent to allocated treatment 191 (86.8) 92 (83.6) 99 (90.0) RD=−6.4% (−15.2% to 2.5%) χ²=1.96 0.162 MD: mean difference; RD: risk difference; RR: relative risk. For time to resolution, a positive MD indicates a longer recovery period with acetic acid. *P*<0.05 was considered statistically significant.* The mean time to clinical resolution was significantly shorter with ichthammol–glycerin packing than with acetic acid drops (5.80±2.10 versus 7.10±2.40 days; MD=1.30 days, 95% CI: 0.70–1.90; p<0.001). Symptom relief within 72 hours was achieved by 92 (83.6%) patients in the packing group compared with 77 (70.0%) in the acetic acid group (RD=−13.6%, 95% CI: −24.8% to −2.5%; p=0.017). Although the overall incidence of treatment-related adverse effects was higher with acetic acid drops (16.4% versus 8.2%), the difference was not statistically significant (p=0.064). Local burning or irritation was, however, significantly more frequent with acetic acid (12.7% versus 4.5%; RR=2.80, 95% CI: 1.05–7.50; p=0.031). Treatment or packing-related discomfort was more frequent in the packing group (12.7% versus 6.4%), but this difference was not significant (p=0.108). Additional topical or systemic treatment was required twice as frequently in the acetic acid group (20.0% versus 10.0%; RR=2.00, 95% CI: 1.02–3.93; p=0.038). Recurrence was also numerically higher with acetic acid drops (11.8% versus 5.5%), although the difference did not attain statistical significance (p=0.093). The mean satisfaction score was significantly higher with packing (8.60±1.20 versus 7.80±1.40; p<0.001), and more patients were satisfied or very satisfied with this treatment (89.1% versus 76.4%; p=0.013). Full adherence was higher in the packing group, but the difference was not significant (90.0% versus 83.6%; p=0.162).

The present study compared 2% acetic acid ear drops with ichthammol–glycerin ear packing in 220 patients with acute otitis externa. Both treatments achieved high overall recovery rates, but ichthammol–glycerin packing produced superior early symptom control, faster resolution, a lower requirement for additional therapy and greater patient satisfaction. The difference was most evident during the first seven days, whereas complete resolution rates became comparable by day 14. Recent reviews have emphasized that topical therapy is the cornerstone of uncomplicated acute otitis externa and that most topical antiseptic, antibiotic and steroid preparations are effective; however, the relative performance may vary with canal oedema, treatment duration and drug-delivery technique. Wiegand et al. (2019)[1], Khatri et al. (2021)[2], Jackson et al. (2023)[3], Di Traglia et al. (2023)[4] and Ellis et al. (2024)[5] similarly identified topical treatment, canal cleansing and effective delivery of medication as the principal components of management. In Table 1, the overall symptom-score reduction at day 7 was significantly greater with ichthammol–glycerin packing than with acetic acid drops (6.50 versus 5.70; mean difference 0.80 points). Clinical success was also higher with packing (90.0% versus 80.0%), while complete clinical resolution at day 7 occurred in 86.4% and 74.5%, respectively. These findings suggest that continuous contact of the medicated wick with the inflamed canal may provide an early therapeutic advantage. Glycerin is hygroscopic and may draw fluid from oedematous tissues, while ichthammol has mild antiseptic and anti-inflammatory properties. The wick may additionally splint the canal and improve local delivery when oedema prevents free penetration of drops. The present results were consistent with Sabarinath et al. (2024)[6], who found significantly greater reductions in pain and external-canal oedema with an antibiotic–steroid pack than with ear drops. Although their medication differed from the present study, their results support the importance of packing as a delivery method in an oedematous canal. Shyamala et al. (2024)[7] also observed substantial early reductions in pain, tenderness and oedema when ichthammol–glycerin was administered through either hydroxylated polyvinyl acetate or cotton wicks. The broadly similar outcomes with the two wick materials suggested that sustained medicament contact, rather than the particular packing material, was the major therapeutic component. Monga et al. (2017)[8] compared ichthammol–glycerin and steroid–antibiotic packs and found that both produced improvement in acute otitis externa. Hussain et al. (2018)[9] likewise reported immediate pain relief with an ichthammol–glycerin wick when compared with steroid–antibiotic drops. Khan et al. (2021)[10], in a study of 250 patients, found comparable overall efficacy and discharge clearance with glycerol–ichthammol and ciprofloxacin–dexamethasone wicks, although the antibiotic–steroid wick produced better tenderness relief. These studies collectively support the clinical activity of ichthammol–glycerin packing, even though differences in comparator therapy, clinical severity and outcome definitions limit direct numerical comparison. Kabadar et al. (2022)[11] reported significant improvement in pain and oedema with both glycerin and antibiotic–steroid packs, with greater early improvement in the antibiotic–steroid group. Similarly, Mustafa et al. (2018)[12] found better day-3 pain control with ciprofloxacin–dexamethasone than with 10% ichthammol–glycerin. Ullah et al. (2024)[13] reported treatment efficacy of 77.1% with ciprofloxacin–dexamethasone compared with 40.0% with ichthammol–glycerin for moderate-to-severe disease. These results do not contradict the present findings because the earlier studies compared ichthammol–glycerin with potent antibiotic–corticosteroid combinations rather than with acetic acid alone. The corticosteroid component can rapidly reduce inflammation, while ciprofloxacin provides targeted activity against common bacterial pathogens. The 80.0% day-7 success rate with acetic acid in the present study nevertheless confirmed that acidification was effective in most patients. Acetic acid lowers canal pH and creates an unfavourable environment for bacterial and fungal growth. Di Traglia et al. (2023)[4], in a systematic review and meta-analysis, concluded that topical antiseptic, steroid and antibiotic monotherapies were all effective and found insufficient evidence that antiseptic therapy was consistently inferior to topical antibiotics. Jackson et al. (2023)[3] similarly stated that no single topical preparation was clearly superior in all uncomplicated cases and recommended selecting treatment according to tympanic-membrane integrity, cost, adherence and adverse-effect profile. The relatively lower day-7 response to acetic acid in the present study may therefore reflect reduced drug penetration through oedematous canals and irritation of inflamed epithelium rather than lack of antimicrobial activity. By day 14, complete resolution was high in both groups 91.8% with acetic acid and 96.4% with packing and the difference was not statistically significant. This convergence indicates that the principal benefit of ichthammol–glycerin packing was acceleration of early recovery rather than a large difference in eventual cure. Ellis et al. (2024)[5] reported that antiseptic preparations such as acetic acid can achieve resolution rates similar to other topical treatments when used for less than one week. However, evidence summarized by Di Traglia et al. (2023)[4] suggested that acetic acid may be less effective when treatment must be extended beyond one week. Thus, the high day-14 resolution rate in the acetic acid group suggests that it remained an effective option for uncomplicated disease, although symptom relief occurred more slowly. Treatment failure at day 7 was twice as frequent with acetic acid drops as with packing (20.0% versus 10.0%). Nevertheless, only 7.7% of all participants required systemic antibiotics. This relatively low use of systemic treatment was consistent with contemporary recommendations that systemic antibiotics should be reserved for infection extending beyond the external auditory canal or for high-risk patients. Bickerton and Mughal (2021)[14] found that oral antibiotics were frequently prescribed unnecessarily or without adequate coverage of the principal pathogens. Mildenhall et al. (2020)[15] also emphasized adherence to recommendations favouring ototopical therapy and avoidance of systemic antimicrobials in uncomplicated cases. Accordingly, the limited requirement for systemic antibiotics in the present study supports appropriate topical-first management. Table 2 demonstrated that ichthammol–glycerin packing produced significantly greater reductions in otalgia, itching, discharge, canal oedema and overall symptom severity. The mean reduction in otalgia was 5.40 with packing compared with 4.60 with acetic acid, and a clinically meaningful reduction of at least 50% was achieved in 90.9% and 80.9%, respectively. Complete resolution of itching, discharge and oedema was also approximately 13.6 percentage points higher with packing. These findings were clinically important because otalgia and canal oedema are the major causes of early morbidity. Sabarinath et al. (2024)[6] observed that packing was more effective than drops in reducing pain and oedema, while Shyamala et al. (2024)[7] demonstrated rapid improvement over the first three days with medicated ichthammol–glycerin wicks. These observations support the proposition that mechanical delivery through a wick becomes particularly valuable when oedema obstructs the canal. The high rates of discharge resolution in both groups were also compatible with the microbiological basis of treatment. Heward et al. (2018)[16] reported that Pseudomonas aeruginosa was the most frequently isolated organism in otitis externa, followed by Candida species and Staphylococcus aureus. Kalra et al. (2024)[17] similarly documented a predominance of gram-negative isolates among culture-positive acute otitis externa cases. These microbiological patterns support the use of topical agents capable of creating an unfavourable local environment or providing direct antimicrobial activity. Nevertheless, culture-guided treatment remains important in recurrent, severe or treatment-resistant disease. Table 3 showed that clinical resolution occurred 1.30 days earlier with ichthammol–glycerin packing (5.80 versus 7.10 days), and relief within 72 hours was more frequent with packing (83.6% versus 70.0%). This finding agreed with studies showing that a medicated wick can facilitate early drug delivery in a swollen canal. The benefit is clinically meaningful because even a one-day reduction in pain and canal obstruction can improve sleep, daily functioning and treatment satisfaction. The present day-7 and day-14 findings also indicate that time-to-response may be a more sensitive endpoint than final cure when comparing effective topical treatments. Any treatment-related adverse effect occurred in 16.4% of patients using acetic acid and 8.2% receiving packing, although the overall difference was not statistically significant. Local burning or irritation was significantly more frequent with acetic acid (12.7% versus 4.5%). This was biologically plausible because acidifying solutions may sting when applied to excoriated or intensely inflamed canal skin. Conversely, discomfort associated with insertion or retention of the pack was numerically higher in the packing group, but the difference was not significant. Contemporary reviews by Wiegand et al. (2019)[1], Jackson et al. (2023)[3] and Ellis et al. (2024)[5] have similarly identified canal irritation, sensitization, tympanic-membrane status and ease of application as relevant considerations when selecting topical therapy. Additional therapy was required in 20.0% of the acetic acid group compared with 10.0% of the packing group. Recurrence was also numerically higher with acetic acid (11.8% versus 5.5%), although the 95% confidence interval included no difference. This result should therefore be interpreted as a trend rather than definitive evidence of reduced recurrence. The follow-up period, baseline severity, adequacy of aural toilet, moisture exposure and adherence could all influence recurrence. Patient satisfaction was significantly higher with ichthammol–glycerin packing: the mean satisfaction score was 8.60 compared with 7.80, and 89.1% versus 76.4% were satisfied or very satisfied. Faster pain relief and fewer burning sensations probably contributed to this difference. Full adherence was numerically higher with packing but did not differ significantly. Although ear packing requires clinician insertion and subsequent removal or replacement, it reduces dependence on correct self-instillation. By contrast, the success of ear drops depends on dosing frequency, application technique and sufficient canal patency. Smith et al. (2021)[18] emphasized the importance of standardized patient-centred outcomes including pain, clinical cure, treatment failure and adverse effects in acute otitis externa trials, supporting the multidimensional outcome assessment used in the present study

Both 2% acetic acid ear drops and ichthammol–glycerin ear packing were effective and generally safe in treating acute otitis externa. However, ichthammol–glycerin packing produced significantly greater early reductions in otalgia, itching, ear discharge, canal oedema and overall symptom severity. It was also associated with faster clinical resolution, higher day-7 clinical success, less need for additional therapy and greater patient satisfaction. By day 14, complete resolution rates were high and statistically comparable between the groups, indicating that both treatments achieved favourable final outcomes. Acetic acid drops remained an inexpensive and antibiotic-sparing option for uncomplicated cases but caused more local burning or irritation and provided slower early relief. Ichthammol–glycerin packing may therefore be preferred when rapid symptom control is required, particularly in patients with marked canal oedema that could interfere with drop penetration. LIMITATIONS OF STUDY This study had several limitations. It was conducted at a single centre, which may limit the generalizability of its findings to other populations and healthcare settings. The open-label nature of the interventions meant that blinding of patients and treating clinicians was not feasible, introducing the possibility of performance and assessment bias. Patient-reported outcomes, including pain relief, treatment adherence and satisfaction, were subjective and susceptible to reporting bias. Variations in the performance of aural toilet, insertion and replacement of the ear pack, and administration technique for acetic acid drops may have influenced treatment response. The relatively short follow-up period limited assessment of long-term recurrence and delayed adverse effects. Microbiological testing was not performed for every participant, and the clinical response was not stratified according to the causative organism or antimicrobial susceptibility pattern. Differences in baseline canal oedema, disease severity, moisture exposure and precipitating factors could also have affected the outcomes. Furthermore, the study did not include a placebo, antibiotic–steroid or steroid-only comparator group, and it did not evaluate treatment Conclusion Both acetic acid ear drops and ichthammol–glycerin ear packing were effective and generally well tolerated in patients with acute otitis externa. However, ichthammol–glycerin packing provided significantly greater early reductions in otalgia, itching, ear discharge, canal oedema and overall symptom severity. It was also associated with higher day-7 clinical success, faster clinical resolution, less need for additional therapy and greater patient satisfaction. Although complete resolution by day 14 was comparable between the groups, local burning or irritation was more frequent with acetic acid drops. Ichthammol–glycerin packing may therefore be preferred when rapid symptom relief is required, particularly in patients with marked canal oedema that could impair the penetration of ear drops. Acetic acid remains an inexpensive, effective and antibiotic-sparing alternative for uncomplicated acute otitis externa. Limitations The study had several limitations. It was conducted at a single hospital, which may limit the generalizability of its findings to other healthcare settings and populations. The open-label design made blinding of patients and treating clinicians impractical and may have introduced performance and assessment bias, particularly for subjective outcomes such as pain relief and satisfaction. The relatively short follow-up period restricted the assessment of long-term recurrence and delayed adverse effects. Differences in the technique of pack insertion, replacement and aural toilet may have influenced treatment response. Treatment adherence in the acetic acid group was partly based on self-reporting, creating the possibility of reporting bias. Microbiological cultures were obtained mainly from patients with visible discharge and were not available for every participant; therefore, treatment response could not be evaluated comprehensively according to the causative organism. Additionally, the study did not include a cost-effectiveness analysis, formal assessment of hearing outcomes or stratified analysis according to baseline disease severity. Larger, blinded, multicentre randomized trials with longer follow-up are required to confirm these findings.

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