Acidifying therapy, best choice in otitis external
Introduction Medicus) and Farnli (the family medicine appendix of the Index Medicu s). Lit Since 1976, a group of about 15 experi erature references found in the selected enced general practition ers, staff members publications were traced and two ENT E.ROOYACKERS-LEMMENS of the department of general practice in textbooks were consulted. Articles were E. VAN DE L1SDONK Nijmegen , meet once a month to discuss excluded from further study when they P. GIESEN common problems in general practice. In concerned one of the following subjects: 1992 some conferences were addressed to malignant otitis externa; in vitro research; Rooyackers-Lemmens E, Van de Lisdonk otitis externa and an orientation in lit surgical therapy; CT-scan. Case-reports EH, Giesen P. Acidifying therapy, best erature was made. Otitis externa is defined and reports concerning undefined otitis choice in otitis externa? Huisarts Wet 1993; as an inflammatory condition of the skin were also excluded. This procedure 36(Suppl): 31-5. of the external ear canal. In the Nether yielded 51 articles. First of all, these ar lands, incidence-figures from general ticles were scanned for information on Abstract Literature was reviewed in order to practice amount to 12-14 cases per 1000 aetiology. Secondly, reports from clinical define a rational therapy in otitis extema based upon aetiology and predisposing factors. In patients per year. It almost equally affects trials were studied, comparing different most casesa bacterial infection turnedout to be all age groups and both sexes.!" Otitis drugs (and/or placebo) in the treatment of present (mainly Pseudomonas Aeruginosa or externa occurs most frequently in summer otitis externa. Reports of trials in which Staphylococcus Aureus); also, an allergic con and in humid tropical areas. Patients com different brands of eardrops were com tact dermatitis or mycosis can be present, par plain of pain, itching, discharge and, less pared, while each contained a combination ticularly in chronic otitis extema. The medica often, hearing loss or a plugged feeling. of an antibiotic and a corticosteroid, were tion of choice is Aluminium acetotartrate. Re Otoscopy reveals erythema, edema and excluded. sistentcasescanbetreatedwithtopicalantibio discharge or desquamation" Acute and tics or topical steroids. Combination of both chronic forms can be distinguished. Seven studies were found and critically drugs is not recommended.Research ingeneral Simple acidifying therapy is recom reviewed according to the following crite practice is neededtostate theoutcomesof using these guidelines. mended for the acute form; there are no ria:" concrete recommendations for chronic - was the study based on an 'inception otitis externa. Moreover, it is only in Dutch cohort ' ? literature that a distiction between a dry was the referral pattern described ? E. Rooyackers-Lemmens, vocational trainee; E.H. van de Lisdonk, GP, MD; P. Giesen, GP. and a wet form of otitis externa is made."!' were the exclusion-criteria described? Correspondence: E.H. van de Lisdonk, It is not clear whether this clinical distinc has complete follow-up been Department of generalpracticeandsocial tion corresponds with different aetiologi achieved ? medicine, Catholic University of Nijmegen. cal factors and, consequently, should be were the demographic and clinical Verlengde Groenestraat 75. 6525 EJ Nijmegen. treated differently. In the Netherlands, characteristics of patients and controls daily practice does not seem to correspond described ? with the advice for acidifying therapy, at was the study designed as a randomized least not according to daily practice of the controlled trial? members of the conferences. In order to have patients and controls been reach consensus on the management more matched for clinical characteristics? knowledge about the aetiology was re have objective outcome criteria been quired . Therefore a study of literature was developed and used? conducted, in order to find the answers to was the outcome assessment 'blind'? the following questions: • Which factors play a part in the aetio Aetiology logy of otitis externa? • Is a treatment with acidifying eardrops The ear canal is well protected against justified in view of these factors? infections by the acidity (pH 5-5,7) of the meatal skin, by the water-resistant, bacte Methods riostatic and bactericidal qualities of ce rumen (thanks to the polyunsaturated fatty Using otitis externa as a keyword, the lit acids in cerumen), and by the outward erature of the last 10 years was screened migration of the meatal skin with about 1,5 referring to Medline (the automatized bib mm per monrh.P'" This natural protection liographic data collection of the Index can decrease as a result of:
HUISARTS EN WETENSCHAP 1993; 36(Suppl) 31 - tissue maceration in case of high envi ronmental temperature and humidity Table 1 Cultures ofpatients with otitis externa and controls. Percentages (tropical climate, swimming); - damage of the skin, caused by for Health y ear canal Otitis externa 38 6 example scratching or syringing the Dibb Man ni Calderon 19 Dibb Manni Calder on ear, or a corp us alienum (hearing aids !); n=77 n=21 n=29 n=226 n=54 n=29 - dermatological diseases, such as ecze Diphteroids 32 38 86 48 ma, psoriasis; 86 81 - alkaline pH, caused by using soap; Staphyloc. C-* 83 90 52 - absence of cerumen, caused by vigo r- S. aureus 4 8 34,1 18 11 ous cleaning of the ear canal, chronic Pseudomonas aeruginosa 22,1 38 50 inflammation, or long-term topica l ap B-hemolyt. streptococ 15,5 4 plication of steroids; Proteus sp 3,5 9 - host resistance lowering conditions Klebsiella sp 5,3 11 3,7 like diabetes, anemia; E.coli 3,5 1,9 anatomical variants, such as a narrow Candida alb 9,3 14 ear canal. Aspergillus sp. 24 The connection between swimming and No growth 9 10 5 4,4 8 1,9 otiti s externa has been confirmed in con * C- = coagulase-negative, predom inantly S. epidermidis trolled studies.":" No controlled studies regarding any of the other ment ioned pre disposing facto rs were found.' 89141520-34 Table 2 Seven studies concern ing compara tive trials to the medication Infection is an important cause of otitis treatm ent ofotitis externa externa; table 1 shows the results of cul tures made ofdiseased and normal ears . In References 16 55 50 52 56 57 24 gene ral, the micro-organisms predomi Number of patients 126 24 66 46 179 110 83 (a) (b) (c) (d) (e) (f) nantly isolated in otitis externa are Pseu Therapeutics (f) domonas aeruginosa (17-64 per cent) and 1 Start cohort + + + + + + + Staphylococcus aureus (11-46 per cent). 2 Selection of patients + + + Pathogenic bacteria are sporadically 3 Exclusion criteria + + + + + found in the healthy external ear canal of 4 Percentage patients control persons." 19 21 35-3? In Norway, dur- follow ed + + * + + * + ing a whole year, a high incidence of S. 5 Characteristics aureus was found together with a low in - demog raphic + + cidence of fungi and yeasts,' whereas in - cinical + + + + swimmers and in subtropical areas a high 6 Randomized + + + + + + + :j: incidence of Pseudomonas was found 7 Matching + 8 Criteria end-results + + + + + + toget her with a moderate high incidence of 9 Double-blind + + + + + fungi and yeasts." 19 Fungi and yeasts also play a role in the following situations: * drop-outs >20 per cent. :t: match ing w as negative (groups were not corresponding). chronic otitis externa; long-term treatment with eardrops containing a corticosteroid; (a) aluminium acetate w ith a comb ination preparation (combination of an antibiotic and steroid) prolonged prophylactic treatment with (b) a solution of boric acid 4% and alcohol 25% w ith two combi nation preparations (c) aluminium acetate w ith a top ical antibiotic antibiotics; in immunocompromised pa (d) hydrocortisone-butyrate w ith a combination preparation tients," ?3? 3940 Ie) acetic acid 2% in aluminium acetate w ith VoSol(R) (chemical composit ion: 2% acetic acid in a propvlene-qlvcol vehicle of 3% propvlene-q lvcol-diacetate, 0.02% benzethonium-chloride en 0.015% In otitis externa of more than two sodium-ac etate) and VoSol-hydrocortisone (VoSol - HC) w ith a combination preparation months' durat ion, 18 per cent of the cul (f) VoSol - HC w ith a combination preparation tures showed no micro-organisms or a nor mal flora (Staphylococci other than S.aureus, corynebacteria)." In such cases an allergic contact dermatitis should be considered; for example caused by chemi cal substances in hearing aids, hair-dye,
32 HUISARTS EN WETENSCHAP 1993; 36(Suppl) a superinfectioncausedby resistantorgan Management of otitis externa in daily general practice isms and could cause hypersensitivity to one of the antibiotics.8911 44 In the USA, • Cleaning of the ear canal. Advise pa 2 No improvement and itching or a dry, eardrops containing both an acidifying tients not to do this themselves. scaly ear canal: start corticosteroid solution and a corticosteroid are recom • Inspection, with special attention to containing eardrops. mendedincaseof otitisexternain patients the ear drum (otitis media, cholestea toma, perforation). A small number of patients will keep with eczemaor psoriasis." • Medication treatment: aluminium symptoms. In case of chronic otitis ex Medicaltreatmentof otitis externa was acetotartrate 6 dd 2 eardrops during 1 terna the following points ought to be the first subject of 17 of the 51 selected week (anti-microbial, dries the exter considered: articles. Of these 17 articles, 6 were re nal canal, not ototoxic); in case of • Avoid a warm humid environment views for postgraduate education, 2 were edema or discharge, first place a cot (swimming), leave off hearing aids follow-up studies of one treatment, 2 were ton plug in the canal and keep it wet (temporarily). studies of the effectsof cleaningthe exter with the aluminium acetotartrate • Culture for fungi and yeasts, espe nal auditorycanal," 48 and 7 were clinical drops for 24 hours. cially in patients who have received trials comparing different medications. In case of obvious improvement in the topical steroids for a long time, immu These 7 were studied according to the first week of use, patient continues the nocompromised patients or patients previously formulated criteria.The results same treatment until the symptoms who have received prolonged pro have disappeared (max. 2-3 weeks). phylactic treatment with antibiotics. are summarized in table 2: all trials meet If symptoms persist after 1 week, ask • Consider allergic contact dermatitis at least 5 of the criteria;two meet 8 crite patients to return. Otoscopic inspection and its predisposing factors. ria;24 52 in four trialsthereis no mentionof reveals: • Consider reference to an ENT special clinical criteria for the diagnosis acute 1 No improvement and discharge: ist, if middle ear disease can not be otitis externa;" 52 5657one includesonly 24 again cleaning, start topical antibio excluded or surgical correction of a patients;" two have a high percentage of tics. narrow ear canal may be necessary. drop-outs.Y" The four clinical trials in whichacidifying therapy forotitis externa was one of the treatments can be sum marizedas follows: chromate in match-heads (used for pick eardrum and in cases where acidifying • In a Family Medical Centre in Cyprus, ing the ear!) and eardropscontainingneo therapy has no effect. Disadvantages of 126 patients were studied. No significant mycine.' 923 28 41-43 Also,diseaseslikeecze- topical antibiotics are the developmentof differences were found between Alumi ma, psoriasis, and diabetes mellitus, and sensibilisation, drug resistance, and oto nium Acetate eardrops and Polymyxine habits like ear-picking, can account for toxicity."!" II 2227284244 505 1 Oral antibio- neomycine-hydrocortisone eardrops(Oto chronic forms of otitis externa.10 2842-45 tics are indicated when the infection sporin")." Chronic otitis externa is more often at spreads to the surrounding tissues outside • In England, in 24 patients referredto an tended by itching, the acute form more the ear canal and systemic signs of infec ENT specialist, no significant differences oftenbypain,hearinglossanddischarge." tion develop, and in cases of serious and were found between a solution of boric As a result of chronic otitis externa irre progressive otitis externa."?1444 Espe acid 4% and alcohol25% on theone hand versible skin changes are described with cially in the Netherlands, eardrops con and polymyxine-fluocinolonacetonide narrowingof the ear canal." 32 Malignant taining corticosteroids are recommended econazol-methanol-glycerol-polyethyle otitisexternaisanextremely rare,butseri for the treatmentof all dry, itchy formsof neglycol eardrops on the other." ous form of otitis externa." chronic otitis externa.l!" 11 23Recently, no • In England, in 66 outpatientsof an ENT difference could be found betweenthe ef department, no significant differences Therapy ficacy of a topical corticosteroid and a were found between Aluminium Acetate combination of a topical corticosteroid eardrops and gentamicin eardrops." All authors recognize the importance of withantibiotics; S. aureusinfections were • In the USA, in 179outpatients,40 otitis cleaning the ear canal ('aural toilet') for evenmoresuccessfullytreatedbythetopi externa ears were treated with acetic acid inspection and application of local ther cal corticosteroid only." In theory, re 2 per cent in Aluminium acetate,40 were apy.4748Acidifying eardrops are oftenrec peated or prolonged use of steroids can treated with VoSoL (a non-aqueous acid ommendedas firstchoiceof therapy. They cause atrophyof the skin.944 52Only a few solution); the remaining ears, showing have an antibacterial effect by lowering authors recommend eardrops that com complications (eczema, allergic reac pH, and restore the natural barrieragainst bine corticosteroids and antibioticsas first tions),were treatedwithVoSoLcombined micro-organisms.2149 Topical antibiotics choice." 263153 Otherswarnagainstthe use withhydrocortisone (VoSoL-HC) orcolis are indicated in cases of perforation of the of such combinations, as they could mask tin-neomycin-hydrocortisone eardrops. In
HUISARTS EN WETENSCHAP 1993; 36(Suppl) 33 the first group 80 per cent of the treated whether a different treatment is required if 7 Dibb WL. Microbialaetiologyof otitis ex ears was cured within one week: pain was a bacterial infection is the probable cause terna. J Infect 199I; 22: 233-9. gone in 92,5 per cent, itching in 60 per of otitis externa than if eczema is the prob 8 PaparellaMM,ShumrickDA. Otolaryngo cent; with VoSol the results were even able cause. logy. Philadelphia: WB Saunders Com pany, 1990. better. In the ears with complications no Concerning the second question, there 9 PoublonRML.De medicamenteuze behan differences were found between the two is little scientific research to the efficacy deling van otitis extema. Geneesmiddelen treatments." The latter was also found in of acidifying therapy that meets the pre bull 1989; 23: 32-4. other trials." 57 viously stated criteria of quality. Never 10 HordijkOJ.Oorpijn,jeuk enafscheidingals theless, the results were remarkably simi symptomen van een ziekoor. NedTijdschr A new development concerns artificial ce lar: acidifying therapy equalizes the effi Geneeskd 1987; 131: 725-7. rumen." The first experiences are promi cacy of the topical use of antibiotics or 11 Anoniem. Samenstellingen toepassing van sing, but further research is needed. combinations of antibiotics and cortico oordruppels FNA. Ned Tijdschr Geneeskd For chronic otitis externa, reference to steroids. It is concluded that an acidifying 1979; 122: 1920-3. an ENT specialist is recommended if the therapy is the first choice in the treatment 12 Tugwell PX. Hoe moeten medische tijd schriften worden gelezen? III. Het beoor presence of chronic middle ear disease can of otitis externa; it is as effective as topical delen van het klinischebeloop en de prog not be ruled out or if - rarely - one con antibiotics and corticosteroids are, but nosevaneenziekte.NedTijdschrGeneeskd siders surgical correction of acquired ste does not entail the risk of complications, 1983; 127:2367-70. nosis of the external ear canal. 10 1429 32 and it is cheap. 13 Stone M, Fulghum, RS. Bactericidal activ As a spin-off from the literature-study, Publication-bias may have played a role ityof wetcerumen.AnnOtolRhinolLaryn some guidelines are proposed for the man in these positive results: negative results gol 1984;93: 183-6. agement of otitis externa in daily general are more likely to remain unpublished. A 14 MarcySM. Externalotitisdue to infection. practice (page 33). second marginal note is the fact that a Pediatr InfectDis 1985; 4(suppl): 27-30. number of trials concerned patients of 15 OsbomeJE, Baty10. Dopatientswithotitis Discussion ENT specialists. This population is a se extemaproducebiochemically differentce rumen? Clin Otolaryngol 1990;15: 59-61. lection of the more complicated and ther 16 LambertIJ. A comparison of the treatment The epidemiology, aetiology and therapy apy-resistant cases, and therefore not rep ofotitisextemawith'Otosporin' andalumi of acute otitis externa is well documented resentative for the general practice pa niumacetate: a report froma servicesprac in literature. Nevertheless, in the Nether tients with otitis externa. Further research tice inCyprus.J R ColiGenPract 1981;31: lands and particularly in general practice in family practice is necessary to evaluate 291-4. the clinical picture has hardly been stu the acidifying therapy. 17 Weingarten MA.OtitisextemaduetoPseu died. Therefore, results can not simply be domonas in swimming pool bathers. J R generalized to the situation of the Dutch Coil Gen Pract 1977; 27: 359-60. general practitioner. With regard to 18 Springer GL, Shapiro ED. Fresh water chronic otitis externa things are less clear: swimming as a riskfactorfor otitisextema: a case-control study. Arch Environ Health there are no consistent definitions for the References I Van de Lisdonk EH, Van den Bosch 1985; 40: 202-6. disease and the aetiology is much more WJHM,HuygenFJA,Lagro-JanssenALM. 19 CalderonR, Mood EW. An epidemiologi complicated. The role of endogenic pre Ziekten in de huisartspraktijk. Utrecht: cal assessment of waterqualityand 'Swim disposing factors (dermatological diseases Bunge, 1990. mer's ear'. Arch EnvironHealth 1982; 37: as eczema and psoriasis, systemic condi 2 Price1. Otitis extema in children. J R Coli 300-5. tions, narrow ear canal) and of exogenic Gen Pract 1976;26: 610-5. 20 Jongkees LBW. Keel-, neus- en oorheel factors (allergic contact dermatitis, ear 3 Lamberts H. In het huis van de huisarts. kunde. Amsterdam:Elsevier, 1984. picking) is insufficiently investigated; 20 Verslag van het Transitieproject. Lelystad: 21 CassisiN,DavidsonT, CohnA,WittenBR. per cent of the cultures (bacteria and fungi) Meditekst, 1991. Diffuse otitis extema: Clinical and micro is negative. Also, aetiologic factors corre 4 Van der Velden J, De Bakker DH, Claes biologic findings in the course of a multi sens AMC,SchellevisFG.NationaleStudie center study on a new otic solution. Ann sponding with dry and wet forms of otitis naar ziektenen verrichtingen in de huisart Otol Rhinol Laryngol 1977; 86(supp\): 1 externa were not found in literature. Re senpraktijk. Basisrapport. Utrecht: Nivel, 16. search does not seem to provide a reliable 1991. 22 PfleidererAG. Otitisextema.Update1988; answer to the question whether these pre 5 De WitG. Otitisextema. Ned TijdschrGe 902-8. disposing factors have consequences for neeskd 1974; 118: 58-64. 23 JobbinsD. Otitisextema. Aust Fam Physi therapy. Of course, in case of allergic con 6 ManniJJ, KuylenK. Clinicaland bacterio cian 1986; 15: 720-6. tact dermatitis , contact with the allergen logical studies in otitis extema in Dar es 24 KimeCE, Ordonez,GE, UpdegraffWR, et will be avoided, so the use of eardrops can Salaam, Tanzania. Clin Otorhinolaryngol al.Effectivetreatmentof acutediffuseotitis be discontinued . But it remains unclear 1984;9: 351-4. extema: a controlledcomparisonof hydro-
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