title: Contact allergy to various components of topical preparations for treatment of external otitis.
abstract: Patients suffering from chronic external otitis had developed contact allergies to one or more compounds of topical preparations in 40% of 142 tested patients. Neomycin and framycetin caused most of the allergic reactions (16.2%) followed by chinoform (7.0%), chloramphenicol and polymyxin (4.2%). Preservatives of the topical otic preparations such as benzethonium chloride (8.5%), benzalkonium chloride (6.3%) and thimerosal (merthiolate) (5.6%) were also common causes of allergic reactions. An epicutaneous test (patch test) using compounds in topical preparations should be done in cases of prolonged, treatment resistant external otitis.
mesh_terms: D000891:Anti-Infective Agents, Local / Q000009:adverse effects* / Q000627:therapeutic use; D003877:Dermatitis, Contact / Q000209:etiology*; D005601:Framycetin / Q000009:adverse effects / Q000627:therapeutic use; D006801:Humans; D009355:Neomycin / Q000009:adverse effects / Q000627:therapeutic use; D010032:Otitis Externa / Q000188:drug therapy*; D010328:Patch Tests; D014677:Pharmaceutical Vehicles / Q000009:adverse effects
chemical_list: D000891:Anti-Infective Agents, Local; D014677:Pharmaceutical Vehicles; D005601:Framycetin; D009355:Neomycin