Case Study: When Tick Bite Makes Red Meat Forbidden

Upon arrival at the Emergency department (ED), doctors began to work on him trying to find out what could be the cause of his multiple symptoms. The patient could be feeling faint as a result of intravascular volume depletion from Gastrointestinal Problem but this is not the only symptom that he was experiencing. Postprandial watery bowel movement could be as a result of a GI Tract infection or maybe malabsorption which might arise from conditions like Celiac Disease.

But seeing that the symptoms were many but localized, it could mean that Mast cells were activated either by allergies or anaphylactic reactions. Mediators like histamine can lead to multi-organ symptoms but what could trigger this mast cells to be activated and cause this much issues. Allergies can be gotten from foods, medications, and our environment but then multi-organ symptoms can also be triggered by underlying conditions like mastocytosis or mast cell activation syndrome.

But doctors will also not rule out the fact that it could be hereditary or drug induced angioedema. If doctors will have to rule out hereditary, then they need to know his history and so it was confirmed that the patient had type2 diabetes, High triglyceride level, rapid heartbeat, a history of kidney stone and ADHD. As expected, he was taking medications to treat these conditions with drug like Metformin, Saxagliptin, metoprolol, atorvastatin, amphetamine, but then started taking Napeoxen and antacid for his abdominal pains.

When he was asked about travel history, he hadn't traveled out of Michigan where he lived at least in recent times and since he wasn't one who liked t try out new dishes, he hadn't eaten any new food or stayed around people who were sick or immunocompromised. While doctors noticed that his temp, oxygen rate, and saturation were normal, his heart rate was fast, and his blood pressure was low. Doctors noticed he had swollen lips and tender soft abdomen with no swollen lymph node, enlarged spleen or liver but he had hives on his neck, scalp, groin, abdomen, and shoulders.

His symptoms may point to Anaphylaxis or as a result of infectious cause. In the case of Anaphylaxis, it can be caused by insect bites, stings, food, or medications. Upon blood work, it was seen that his white blood cell count was very elevated up to 26500 mm³ compared to the normal 4500 to 11000mm³ which just confirms that previous suspicion, high lactic acid, his iron levels were normal so he was not anemic, Serum sodium levels were low, elevated serum troponin level suggested inadequate blood flow to the heart, and he had a reduced kidney function. The patient was tachycardic and trust me, this is a lot for one person, so what could be the cause?

Soon the patient began to show signs of possible shock which just showed that it could be histamine levels causing the problem and epinephrine should be considered to prevent anaphylaxis. Four days later his condition worsened as he had tightening of the chest, worsening rash, tachycardia, hypotension, wheezing, and reduced oxygen saturation. When Blood work came back, it showed that he had elevated tryptase level, and elevated Serum IgE level which indicated that he was suffering from an allergy. Let me state that his condition became better after he was administered epinephrine and treated on the first day he came to the hospital, so it forced doctors to ask what could have triggered the attack on the forth day.

Doctors requested to know what he ate at the hospital on the forth day and he mentioned that he had eaten beef 4 hours before his symptoms worsen. I could imagine the medical practitioner having the light bulb moment like I got the cause. So he was asked about his hobbies and job, and he mentioned that he was a deer hunter who hunted white-tailed deer and he had eaten venison 2 days before he came to the emergency department.

Alpha-Gal Allergy was the next suspect on the board. Galactose -alpha-1,3-galactose (Alpha-Gal) is a carbohydrate that is not present in humans but present in all non-primate mammals. So exposure to the carbohydrate can cause the body to see it as foreign thereby causing the immune system IgE antibodies to react directly which would lead to an allergic response when they eat red meat.

Remember I mentioned tick at the beginning of this post, yes the Lone-star Tick (Ambluomma Americanum) is a vector for this exposure in humans and the carbohydrate found in the saliva contains the ticks. One of the animals these tick feed on is the white-tailed deer. This patients might have been bitten by the tick while hunting or brought it into his home without knowing and so got the carbohydrate in his body. He was diagnosed with Alpha-Gal syndrome and was discharged after given glucocorticoids, and antihistamines and he was given a patting warning which is to stay away from red meat. Months later when he was tested again, he still had the Alpha-Gal IgE in his blood but his tryptase level was normal this time around.

^{Post Reference}

^{https://pmc.ncbi.nlm.nih.gov/articles/PMC9306225/
https://pmc.ncbi.nlm.nih.gov/articles/PMC3085643/
https://pmc.ncbi.nlm.nih.gov/articles/PMC8344025/
https://www.cdc.gov/alpha-gal-syndrome/about/index.html
https://www.nhs.uk/conditions/anaphylaxis/}

^{Image Reference}

^{Image 1 || Flickr || Lone Star Tick Bite
Image 2 || Flickr || ER not comfortable, patch of nitroglycerin on my chest
Image 3 || Flickr || DSC_1491}