Meat allergy after tick bite?

Summer is here and lots of of us are spending more time outdoors. We understand how necessary it’s to wear insect repellent, not only to guard ourselves from annoying insect bites, but more importantly, to guard ourselves from diseases carried by mosquitoes, lice, fleas and ticks. We worry about viruses (like yellow fever), bacteria (like Lyme disease) and parasites (like malaria), but did you realize that a tick bite also can cause a meat allergy?

Alpha-gal syndrome is a variety of food allergy to pork. In the United States, this immunoglobulin E (IgE)-mediated allergic response is attributable to the bite of the star tick (which carries a carbohydrate molecule called galactose-alpha-1,2-galactose (alpha-gal) into the body). Alpha-gal is present in the cells and tissues of all mammals except primates (i.e., humans, chimpanzees, and monkeys) (Commins, 2019). The ticks that cause alpha-gal syndrome pick up the molecule from the blood of the animals they bite. When a tick bites an individual, alpha-gal is transferred into the person’s body. Several tick bites may cause the immune system to change into sensitive to pork, which may range from a light response to a severe and/or life-threatening anaphylaxis.

The star tick is found primarily within the southeastern United States, but has spread to the northern and western parts of the country. Alpha-gal syndrome has also been reported in Australia, Spain, Germany, Japan, and Sweden, and should be attributable to other kinds of ticks, similar to (Commins, 2019)

Symptoms of an allergic response can appear anywhere from two to 10 hours after eating pork, unlike other allergic reactions to foods that always occur inside minutes of consumption. Symptoms include:

• Hives, itching, peeling skin
• Swelling of the lips, face, tongue, throat
• Dizziness, hypotension, fainting
• Dyspnoea
• Runny nose, sneezing
• Abdominal pain, diarrhea, nausea, vomiting
• Headaches
• Anaphylaxis

The best technique to prevent alpha-gal syndrome is to guard yourself from tick bites.

• Cover exposed body parts: wear shoes, long pants, long-sleeved shirts, a hat, and gloves.
• Stay on the paths and avoid going through bushes and tall grass.
• Use insect repellents when in grassy and wooded areas.
  • Use a repellent containing DEET, picaridin, IR3535, oil of lemon eucalyptus (OLE), para-menthanediol (PMD), or 2-undecanone.
    • Spray children with repellent, avoiding hands, eyes and mouth.
    • Repellents mustn’t be used on children under 2 months of age.
    • Products containing OLE or PMD mustn’t be used on children under 3 years of age.
  • Apply 0.5% permethrin to shoes, clothing, camping equipment or wear previously treated clothing.
• After spending time outdoors, check for ticks.
  • Check pets, coats and backpacks rigorously
  • Do a full body examination: underarms, in and across the ears, behind the knees, within the hair/scalp/neck, between the legs, and across the waist.
• Take a shower to remove any ticks that will not be attached to your skin.
• To kill ticks, wash clothes in hot water and tumble dry on high for 10 minutes.
• For ticks which are attached to the skin (CDC, 2019):
  • Using tweezers, grasp the tick as near the skin as possible.
  • Pull gently with regular pressure, being careful to not crush or crush the tick.
  • After removing the mask, clean your skin and hands with isopropyl alcohol or soap and water.
  • You can do away with a tick by placing it in alcohol, a sealed container, or flushing it down the bathroom.

• Alpha-gal syndrome is normally diagnosed based on a medical interview and a blood test to evaluate the presence of alpha-gal antibodies within the blood.
• Beef is the pork that the majority often causes this allergic response, but alpha-gallate can be triggered by gelatin, milk, and a few cheeses.
• Red meat ought to be avoided in all forms, including broths, sauces, meat extracts and spices.
• Patients should carry an epinephrine auto-injector (e.g., EpiPen, Auvi-Q) in case of severe allergic reactions.
• Typical emergency treatment for anaphylaxis includes adrenaline, a histamine blocker, and corticosteroids.
• Inform patients that they might have an allergic response to products containing gelatin, similar to those present in intravenous colloid solutions, vaccines, capsules, and suppositories (Stewart et al., 2015).
• Heart valve alternative in pigs may cause a life-threatening allergic response (van Nunen, 2015)

Center for Disease Control and Prevention (2019). Tick Removal and Testing. Retrieved from https://www.cdc.gov/lyme/removal/index.html

Center for Disease Control and Prevention (2018). Prevention of tick bites in humans. Retrieved from https://www.cdc.gov/lyme/prev/on_people.html

Commins, SP (2019). Meat allergy. Retrieved from https://www.uptodate.com/contents/allergy-to-meats?search=lone%20star%20tick

Mayo Clinic (2019). Alpha-gal syndrome. Retrieved from https://www.mayoclinic.org/diseases-conditions/alpha-gal-syndrome/symptoms-causes/syc-20428608.

Stewart, PH, McMullan, KL, and LeBlanc, SB (2015). Delayed pork allergy: clinical consequences of galactose-α-1,3-galactose sensitization. (4), 260-264. DOI:10.1016/j.anai.2015.08.003

Strickler, J. (2017). Mammalian meat allergy: an unexpected danger. (8), 47-51. DOI:10.1097/01.NURSE.0000521027.38133.7d

Van Nunen. (2015). Tick-induced allergies: mammalian meat allergy, tick-borne anaphylaxis and their significance. (1), 3-16. DOI:10.5415/apalergy.2015.5.1.3