Conductive hearing loss developing during childhood is usually due to otitis media with effusion and may present with speech and language delay or difficulty hearing. Later onset of conductive hearing loss may have an obvious cause such as an ear infection, trauma or upper respiratory tract infection or may have an insidious onset related to chronic middle ear disease, otosclerosis or a tumour of the naso-pharynx. Earwax is a very common cause of a conductive hearing loss which may present suddenly when the wax blocks sound from getting through the external ear canal to the middle and inner ear. Diagnosis
Diagnosis requires a detailed history, local examination of the ear, nose, throat and neck, and detailed hearing tests. In children a more detailed examination may be required if the hearing loss is congenital. Otoscopy
Examination of the external ear canal and ear drum is important and may help identify problems located in the outer ear up to the tympanic membrane. Differential testing
For basic screening, a conductive hearing loss can be identified using the Rinne test with a 256 Hz tuning fork. The Rinne test, in which a patient is asked to say whether a vibrating tuning fork is heard more loudly adjacent to the ear canal (air conduction) or touching the bone behind the ear (bone conduction), is negative indicating that bone conduction is more effective that air conduction. A normal, or positive, result, is when air conduction is more effective than bone conduction.
Linear and whorled nevoid hypermelanosis (also known as "Linear nevoid hyperpigmentation," "Progressive cribriform and zosteriform hyperpigmentation," "Reticulate and zosteriform hyperpigmentation," "Reticulate hyperpigmentation of Iijima and Naito and Uyeno," "Zebra-like hyperpigmentation in whorls and streaks," and "Zebra-line hyperpigmentation") is a disorder of pigmentation that develops within a few weeks of birth and progresses for one to two years before stabilizing. : 549   There is linear and whorled hyperpigmentation following the lines of Blaschko without preceding bullae or verrucous lesions. : 549   It is important to exclude other pigmentary disorders following the Blaschko lines before making a diagnosis of linear and whorled nevoid hypermelanosis. The differential diagnoses include incontinentia pigmenti, linear epidermal nevus, hypomelanosis of Ito and Goltz syndrome. Recently, a case of linear and whorled nevoid hypermelanosis was reported in a Malaysian Chinese girl. See also
Skin lesion
List of cutaneous conditions

References


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