Anaphylaxis is a severe and potentially life threatening allergic reaction often associated with foods such as peanuts or shellfish. A recent case involving an energy drink, however, has focused attention on an unexpected ingredient hiding in some beverages and supplements.

According to a report from the American College of Allergy, Asthma and Immunology, a boy, 15, experienced a severe allergic reaction after trying a new energy drink. Symptoms included "widespread hives," wheezing and difficulty breathing.

The case was presented at the ACAAI’s 2026 Annual Scientific Meeting, held Nov. 12 through 16 in Phoenix, Arizona. The report described the reaction and the medical treatment required to bring the teenager’s symptoms under control.

The teen was taken to a hospital, where he received two doses of epinephrine. He was also treated with albuterol, an antihistamine and IV fluids, and his symptoms resolved following treatment.

A review of the beverage label revealed that the energy drink contained 5 grams of collagen derived from cod. That ingredient became a focus because of the teenager’s previous experiences with certain fish.

The teen reported mild throat itching and swelling of his lips when eating canned tuna. He had eaten salmon without a problem and also had eczema, asthma and allergic rhinitis, commonly called hay fever.

Despite the symptoms associated with tuna, skin prick testing for allergies to tuna, cod and flounder returned negative results. The findings highlight the complications that can arise when different proteins are involved in allergic reactions.

The research remains preliminary because it was presented at the ACAAI conference. It had not yet been published in a journal following peer review, according to the report.

Allergist Annabelle Rowland, M.D., the study author and an ACAAI member based in Georgia, said the case demonstrates "how tricky fish allergy can be."

"Collagen from fish is showing up in a growing number of products, from drinks to supplements," Rowland said. "Standard fish allergy tests mostly look for a different fish protein and contain very little collagen, so a person can test negative and still react."

A spokesperson for the Council for Responsible Nutrition in Washington, D.C., told Fox News Digital that collagen ingredients can come from several animal sources, including fish, cattle and pigs. The spokesperson urged consumers to consider their health needs and sensitivities when selecting products.

"Fish-derived collagen can pose an allergy risk for people sensitive to fish, and processing or hydrolysis does not necessarily eliminate that risk," the spokesperson said.

The organization also cautioned against drawing broad conclusions from one reported case. "The case presented at ACAAI highlights the importance of allergen awareness, but a single suspected reaction does not establish how frequently such reactions occur," the spokesperson added.

Manufacturers are legally required to provide accurate ingredient information and disclose major allergens, according to the council. Those disclosures are intended to help consumers make informed decisions about the foods, beverages and supplements they use.

Sung Poblete, Ph.D., CEO of Virginia based Food Allergy Research & Education, told Fox News Digital that fish collagen is increasingly being used in supplements, beverages and wellness products. She said reactions can differ among people and among proteins derived from different fish.

"While many people with fish allergy avoid all finned fish, reactions can vary between individuals and between different fish-derived proteins," Poblete said. "So someone can be allergic to one type of fin fish and not another."

Poblete said labels must identify the species of fish used in a product. Crustacean shellfish, including shrimp, crab and lobster, must also be identified specifically, according to the FDA.

"For someone managing fish or shellfish allergy, 'marine collagen' on a label calls for a closer look at the ingredient list and 'contains' statement," Poblete said. "If the source still isn’t clear, FARE encourages people to call the manufacturer before using the product."

Consumers are encouraged to ask manufacturers what collagen is made from and how products are sourced, packaged and tested for allergens. Poblete also urged people to discuss any reaction with an allergist, even when an allergy test returns a negative result.

"This case offers a timely reminder to read every label, including on drinks and supplements, and talk with an allergist about any reaction, even if a test came back negative," Poblete said. Fox News Digital reached out to energy drink manufacturers for comment.