Smith-McGuckin spot.

Direct inspection of the tympanic membrane, especially with the help of the microscope, continues to be an important part of the examination of the patient suffering from ear disease. Accurate assessment of the varied appearances can be helpful in anticipating the prognosis in SMOM and may give information about the pathology of CSOM and cholesteatoma. The Smith-McGuckin spot was first described 20 years ago (Smith 1964, R Thomas 1965, personal communication) and its significance is reviewed. Further evidence of the relationship between skeletal disorders such as Turner's syndrome and persistent SMOM is described. It is suggested that bone resorption in the deep meatus, outer attic wall and ossicles may result from chronic hyperaemia rather than sepsis or avascular necrosis. The part played by cholesteatoma in bone erosion is questioned.