The Nature of a Nosebleed

Although it is recognised that any local inflammation or trauma is likely to result in a nosebleed, the precise mechanisms by which most epistaxis occurs are still poorly understood. It is known that epistaxis presentations to the ED are more common in the winter months, [1] probably reflecting a higher incidence of upper respiratory tract infections and lower atmospheric humidity.

There are also two well defined peaks in epistaxis prevalence occurring at the extremes of age, [1] which may reflect different aetiological causation.

Children

In children, it is hypothesised that staphylococcal colonisation of the anterior nasal cavity is an important factor in producing both crusting of the mucosa and subsequent epistaxis. [11]

Adults

In adults, a number of different aetiological associations have been described. Recent heavy (within 24 hours) or regular high alcohol intake is associated with an increased risk of non-traumatic epistaxis, [12] as well as systemic drugs usage including anticoagulants and antiplatelet drugs. [13]

Environmental factors such as humidity, altitude, exposure to irritants e.g. dust, cigarette smoke or certain chemicals also increase the risk of epistaxis. Other general causes of damage include Atherosclerosis, increased venous pressure from mitral stenosis and Haematological conditions affecting clotting (Thrombocytopenia, haemophilia, Von Willebrand disease, platelet dysfunction and leukaemia). [13]

Trauma is identified as a local cause damaging blood vessels. It can result from an injury from nasal fractures, blunt trauma, septal ulcers or perforations, nose-picking or foreign body. [13]

Local causes of damage to the blood vessels may also include [13]:

• Vascular causes
• Post-operative bleeding
• Tumours
• Nasal oxygen therapy
• Inflammation (e.g. infection, allergic rhinosinusitis, or nasal polyps).
• Topical drugs (e.g. cocaine, decongestants, or corticosteroids).