Cookie Notice

This site uses cookies. By continuing to browse this site, you are agreeing to our use of cookies. Review our cookies information for more details.

OK
skip to main content

Steel head trout and salmon allergy

Question:

2/28/2020
What do you advise salmon-allergic patients with regards to ingestion of steelhead trout, given that the latter is a trout but a member of the Salmonidae family?

Answer:

In one stud, the ELISA inhibition test, the rates of IgE-binding inhibition caused by different species in the same genus, silver salmon and rainbow trout, were about 50%. (1)

Using DNA analysis, Kuehn looked at cross-reactivity to fish species. The parvalbumin content in fresh fish was on average: 4.5 mg/mL for herring, 3.8 mg/mL for carp, 2.5 mg/mL for redfish, 2.3 mg/mL for salmon/ trout, 2.0 mg/mL for cod, 0.6 mg/mL for mackerel, and < 0.05 mg/mL for tuna. Using DNA-based assay, the sensitivity to detect parvalbumin varied significantly between different species of fish. In this study, we developed polyclonal antibodies that were able to detect the parvalbumins of eight frequently consumed species of fish (salmon, trout, carp, cod, mackerel, redfish, herring, tuna) with a comparable sensitivity. (2)

Helbing, et al, using radioallergosorbent inhibition testing demonstrated significant cross-reactivity among pollack, salmon, trout, and tuna. (3)

Based on these data, cross-reactivity between steelhead and salmon is compelling. While the ultimate answer is how relevant is this in clinical practice. I live in Alaska, where salmon is a significant component of subsistence. Among the Native population, I have patients that react to King Salmon (coho) but can eat Red Salmon (sockeye). I have wanted to do a study on this for many years. So, I think armed with the information that there is indeed probable cross-reactivity, you may consider a controlled challenge. All commercially bought steelhead will be farmed, not wild, which may have some significance.

In summary, yes, there is clearly cross-reactivity between steelhead trout and salmon.

1) Kondo Y, Ahn J, Komatsubara R, et al. Comparison of allergenic properties of salmon (Oncorhynchus nerka) between landlocked and anadromous species. Allergol Int. 2009;58(2):295–299. doi:10.2332/allergolint.08-OA-0064

2) Kuehn A, Hilger C, Graf T, Hentges F. Protein and DNA-based assays as complementary tools for fish allergen detection. Allergol Select. 2017;1(2):120–126. Published 2017 Aug 4. doi:10.5414/ALX01485E

3) Helbling A, McCants ML, Musmand JJ, Schwartz HJ, Lehrer SB. Immunopathogenesis of fish allergy: identification of fish-allergic adults by skin test and radioallergosorbent test. Ann Allergy Asthma Immunol. 1996;77(1):48–54. doi:10.1016/s1081-1206(10)63479-5

I hope you find this helpful

Respectfully submitted,
Jeffrey G Demain, MD, FAAAAI