Alternobaric vertigo may develop if pressures in the left and right middle ear are not equal during ascent.
Risk factors:
(1) upper respiratory tract infection
(2) allergic rhinitis
(3) middle ear infection
(4) mass lesion in the middle ear
(5) obstructing lesion in the external ear canal
Signs and symptoms:
(1) ear pain
(2) bloody otorrhea (with external ear barotrauma if the external canal is blocked)
(3) vertigo
An inexperienced diver may panic if these symptoms occur unexpectedly.
Management:
(1) A person should not dive until all symptoms related to the ears have cleared.
(2) Decongestants may help reduce blockage associated with viral infections or allergies.
(3) Antibiotic therapy may be indicated if there are signs of otitis media.
(4) Analgesics can help relieve acute pain.
(5) Keep the external ear canal free of obstructions (cerumen and foreign bodies).
(6) The pain can be relieved by descending a few feet in the water. The diver can then slowly try ascending again.
