Epistaxis (or “nosebleed”) is the occurrence of hemorrhage from the nose. It is a quite common phenomenon, especially during childhood. At this age, indeed, the nasal mucous membrane tends to be thinner and more delicate. The main problem is that under this thin nasal epithelium there is a great density of capillaries, whose function is to warm the air that we inspire before it reaches the lungs. Nosebleed occurs when these capillaries and the mucous membrane that protects them lose their integrity.
It is quite difficult to estimate the real incidence of epistaxis, mainly because most episodes are self-limited, and thus not reported. Epistaxis comes to medical attention only when it is recurrent, or particularly severe. A recent study by Pallin et al. has found that the incidence of these severe cases is of 1.7 cases per 1,000 population in a year. It has also pointed out that the age-related risk has two peaks, being significantly higher in children under 10 years old and in old people over 70 years old.
Epidemiology of epistaxis in US emergency departments, 2005
The pathogenesis of nosebleed is quite various. It may be caused by some local factors, but, in some more severe cases, some systemic factors may be involved.
Among the possible local causes we find:
- local traumas (usually a blunt trauma, e.g. a punch, possibly accompanied by a nasal fracture)
- exposition to environmental irritants, that may cause a severe local inflammatory reaction; inflammation leads to some local changes, such as vasodilatation, increased permeability, increased blood flow and increased blood pressure; the consequence is an increased risk of capillary ruptures
- frequent use of nasal sprays, in particular corticosteroid nasal sprays; corticosteroids reduce inflammation, but, on the other hand, they enhance protein catabolism, and this leads to an increased capillary fragility
On the other hand, the main systemic conditions that may lead to epistaxis are:
- hypertension; an increase in blood pressure raises the risk of capillary ruptures
- vitamin C deficiency (as in the case of scurvy); vitamin C is required for the synthesis of collagen, the most important component of connective tissue; defective connective tissue leads to fragile capillaries, resulting in abnormal bleeding
- heart failure (in particular right-sided failure); in this condition there is an increase in systemic venous pressure and, as a consequence, also in systemic capillary pressure; this condition raises the risk of capillary ruptures
- hyperthermia; hyperthermia induces an extreme peripheral vasodilatation (in order to increase heat dissipation); this raises the risk of capillary ruptures
- alcohol consumption; alcohol inhibits the vasomotor center, thus causing a persistent peripheral vasodilatation in case of chronic abuse; this results in an increased risk of capillary ruptures
- any condition impairing the system of coagulation; the patient loses his ability to stop bleeding when a blood vessel is broken:
Effects of alcohol on hemostasis, 2005
Most cases of nosebleed, however, occur spontaneously, with no obvious cause.
When nosebleed is determined by a specific factor, the therapy usually aims to remove this primary cause (removal of the environmental irritants in case of irritation, antihypertensive treatment in case of hypertension, vitamin C supplement in case of scurvy, treatment of the specific bleeding disorder in case of impairment of the coagulation cascade, and so on).
But what about all those cases of spontaneous nosebleed? Nosebleed is not a dangerous event, but, especially if it occurs frequently, it may be somewhat annoying. Therefore, in some cases it may be advisable to take action against this problem. And, before coming to drugs, the simplest remedy suggested by the General Practitioner is usually to drink a certain daily amount of bilberry juice.
Why should the doctor give such an advice? Which are the molecules contained in the bilberry? Which ones help counteracting the nosebleed? How do they act?
We find the answer to all these questions in some specific polyphenolic compounds, anthocyanins of whom bilberry is very rich.. Anthocyanins, indeed, are able to exert a general antioxidant and a specific vasoprotective action. In this way, they manage to increase capillary strength, thus helping to prevent bleeding in all conditions of extreme capillary fragility.