In the Annals Of Surgery July 1937 Dr Urban Maes from New Orleans wrote an article about “The Infections of the dangerous areas of the face”. He mentions that this topic was first discussed by Ludlow who wrote about 6 patients with minor infections of the face (pimple or boil on the lip) in 1852. Three of those patients died within a short period of admission after pinching or scratching the pimple initially. Dr Maes did not realise that the cause of deaths were due to cavernous sinus thrombosis as the postmortem then did not check the brain. It was not until 1883 that Sir Frederick Treves offered the first explanation as to why infections of certain areas of the face were dangerous. He correctly predicted that the cause of death in these patients was due to thrombosis of cerebral sinuses.

As medical students we have all been taught that infection involving the area now known as “Danger Triangle of the Face” must be treated promptly as there is a big risk of patients developing Cavernous Sinus Thrombosis which could be fatal. I remember a young man who was admitted to our hospital when I was a houseman 45 years ago. He had severe infection of the face (multiple pustules). He was otherwise perfectly normal. We started IV antibiotics soon after admission. However within 12 hours of admission he was dead. I can never forget this incident. The public are still unaware of the seriousness of infection affecting this region. They tend to ignore or treat a pimple or infection in the area as they would an infection on their arm or leg.

The danger triangle of the face as its name implies is a triangular area with the tip of the triangle at the medial angle of the eye and the base present covering the lower part of nose and the upper lip. See figure. It is the Area in the Face from where infection can spread to the Cavernous Sinus leading to Cavernous Sinus thrombosis. Infection can easily spread to the brain from here.

The Cavernous Sinus is located in the middle of the skull base on either side of the basisphenoid bone. They are two blood filled spaces consisting of a large number of thin walled veins. It is considered as a complex neurovascular structure as it houses not only cranial nerves 3, 4, 6 and 5 (i and ii) but also the internal carotid artery. It also serves as a venous drainage route for the orbit and base of the skull. It is the only place where a major artery runs through a space filled with venous blood.

How is the cavernous sinus connected to the “Danger triangle of the face”:

Facial vein communicates with the cavernous sinus through two routes. Near the medial angle of the eye the supra orbital vein, a tributary of the facial vein communicates with the superior ophthalmic vein present in the orbit. The superior ophthalmic vein drains into the cavernous sinus. The other route is through the the deep facial vein draining in to the pterygoid venus plexus that communicates with the cavernous sinus.The facial vein and its communicating veins do not possess valves and therefore blood can pass in both directions.

Initial Symptoms of a cavernous sinus thrombosis:
? a sharp and severe headache
? swelling and bulging of the eyes
? eye pain that is often severe

More Serious Signs:
As cranial nerves III, IV, VI and opthalmic and maxillary branches of V pass through the cavernous sinus, thrombosis and infection of the sinus may cause severe clinical symptoms through pressure on the respective nerves. As cranial nerves 3, 4 and 6 supply muscles controlling eye movements, symptoms may relate to loss of certain movement of the eye. Rarely if the swelling is considerable it may even cause pressure on the optic Chiasma or sometimes the pituitary gland.

Most cases of cavernous sinus thrombosis occur when a bacterial infection in another part of the skull or face spreads into the cavernous sinuses. In around 7 out of every 10 cases, staphylococcus is responsible. It often appears a few days before cavernous sinus thrombosis.

Investigations:
? Routine blood tests should include blood culture for pathogens.
? A CT scan and or MRI scan

Treatment:
Cavernous sinus thrombosis will need urgent active treatment in a hospital. The main treatment will be through intravenous antibiotics. The treatment can last for several weeks. The addition of steroids and anticoagulants may be needed in severe cases.

Complications:
Although cavernous sinus thrombosis is thought to be rare, it can affect people of all ages and once diagnosed is an extremely serious condition. Even with prompt treatment, as many as one in three people with the condition die. Around 1 in 10 people who survive will develop long-term health problems as the result of damage to their brain, such as persistent headaches and fits, or some degree of visual impairment.