How being allergic to cats can make you allergic to pork

Author: Louise Bourdery

Earlier this year, a Portuguese research group published one of the very few articles found in the scientific literature on the pork-cat syndrome. This is a good opportunity to introduce and raise awareness about this rather rare disease.

In their publication, Joana Barradas Lopes and her colleagues report the well-documented case report of a patient. This patient, a 51-year-old female has a history of recurrent asthma when exposed to cats, since childhood. After years of tolerating mammalian meat, this patient had been experiencing an intense and generalized itching a few minutes after ingestion of  well-cooked pork meat for a while.

Many routine diagnostic tests were performed and the pork cat syndrome was diagnosed and a strict pork-free diet was prescribed. With this eviction diet, no more episode occurred in the patient.

The pork-cat syndrome was first described in 1994 by Martine Drouet and her research team, and since then, very few publications have been issued. Before  looking into the details of this syndrome and into what it entails for the patients, here is a short reminder on what allergic diseases are.

An allergy, also known as hypersensitivity, is when the body reacts to typically harmless substances such as specific foods or animals. This reaction can range from mild symptoms (e.g. red eyes, sneezing, coughing) to a more severe reaction or death, if not treated in time.

Although allergic diseases have increased in the Western part of the world for a couple of decades, the pork-cat syndrome remains a very rare condition. However, about 1% to 3% of patients allergic to cats seem to be at higher risk of developing a pork meat allergy.

How can someone with a cat allergy develop an allergy to pork meat? This is partly due to a great similarity among the different species of mammals. More specifically, it is due to a similarity in their serum albumin, a protein found in the blood of vertebrates, which leads to a cross-reactivity.

It is thought that an initial sensitization to cat serum albumin is followed by an allergic reaction after ingestion of pork meat containing pork serum albumin. Given these similarities leading to a cross-reactivity, other mammalian meat such as beef may as well induce an allergic reaction in pork-cat syndrome patients.

Despite its rarity, this type of allergy may be easily manageable as long as it is properly and accurately diagnosed. The correct diagnosis is crucial to avoid any severe reaction which might lead to a fatal outcome if not managed.