[Itching in the external ear--a side effect of ear plugs]

The object of this investigation was to assess the frequency of itching in the external auditory meatus in individuals who use hearing aid ear plugs (OP) and, simultaneously, to assess the cause of the itching. Seventy-six of the patients examined consecutively in the audiological department (ages 34-89 years) were questioned about itching and were submitted to an objective ear, nose and throat examination, audiometry and culturing from the external meatus for bacterial and fungal growth. In 20 patients, patch tests were made for allergic reactions from which the ear plugs were made (heat polymerized methyl methacrylate). None of the 20 patients had become sensitized. Itching in the external auditory meatus was found to be a side effect of employment of ear plugs with an incidence of 39% as opposed to only seven in ears without ear plugs (p less than 0.05). The incidence of itching was not reduced in ears with a ventilation channel in the ear plug. In 38% of the itching ears no objective changes were observed and, in the remaining cases, the changes were frequently limited. Potentially pathological bacterial growth was found to be significantly more in ears with ear plugs (1- greater than 16%, p less than 0.05) and in itching ears (4- greater than 24%, p less than 0.05). In ears with potentially pathogenic bacteria, objective changes were nearly always found. In the vast majority of cases, the potentially pathogenic bacteria were Gram-negative, corresponding to the findings in external otitis in the tropics and mixed infections with fungi were frequently present.(ABSTRACT TRUNCATED AT 250 WORDS)