Tick bites cause lethal meat allergy

DOCTORS are warning of a new reason to avoid tick bites: they can give you a potentially deadly allergy to meat.

The tiny insects, increasingly common in the British countryside and parklands, are already known to infect humans with the debilitating illness Lyme disease.

But now doctors have discovered that they can also make people permanently allergic to the likes of beef, lamb and pork.

NHS medics reported the cases of five patients who developed serious allergic reactions to these meats.

They added that there is no remedy to the tick-borne allergy – the only thing sufferers can do is practise the ‘ complete avoidance’ of red meat.

The warnings from doctors at the al l ergy departments of Addenbrooke’s Hospital i n Cambridge and Guy’s and St Thomas’ NHS Foundation Trust in London, are published in the journal Annals of Allergy, Asthma and Immunology.

Their scientific paper explains that some ticks carry a type of sugar called ‘alpha-gal’, which is found in most animals – but not primates such as humans. The ticks pick up the alpha-gal from biting animals such as sheep or deer, carry it in their saliva, and then pass it on to humans when they bite us. Usually, people are not allergic to the alpha-gal found in meat when they eat it, as the substance simply passes through the digestive system without being ‘seen’ by the immune system.

But if alpha-gal is introduced multiple times into the bloodstream – such as when a person is bitten repeatedly by ticks carrying it – then an i ndividual’s i mmune system may regard it as an alien substance and develop armies of antibodies to fight it.

As a result, the next time they are exposed t o alpha- gal by eating meat or perhaps even just smelling it cooking, they develop a reaction.

Symptoms can include hives, stomach ache, swelling of the windpipe, and even anaphylactic shock. And while most allergic reactions tend to occur immediately, tick-induced red meat allergy is often delayed, starting three to eight hours after eating.

The doctors added that there was currently a ‘ considerable lack of awareness of the allergen’ with just 21 per cent of patients being correctly diagnosed within a year of developing symptoms, despite the risk of life-threatening anaphylaxis.