🟠 (Fish Roe Allergy: Salmon Roe - Pollack Roe)

Eggs (like salmon roe, pollock roe, etc.) are increasingly being consumed by infants and young children, and immediate allergies (IgE-mediated) to these eggs can occur.

Is caviar/pollock allergy easy to cure?

Large-scale, long-term follow-up data showing the "tolerance acquisition rate (recovery rate)" for ikura (salmon roe) and tarako (walleye pollock roe) allergies is limited.
However, case reports and small-scale studies suggest that fish roe allergy is not a type that frequently resolves spontaneously (acquires tolerance), and that many cases persist.

2) Symptoms (ranging from mild to severe)

Symptoms of fish roe allergy range from mild, such as skin symptoms (hives, etc.), discomfort in the mouth and throat, and abdominal pain, to severe anaphylaxis.
Additionally, cases have been reported where a strong reaction occurs with fish roe alone, but fish (fish meat) can be eaten (i.e., an allergy to fish roe only).

3) Why it's prone to happen (Properties of protein)

The major allergen in fish roe (especially salmon roe) is known to be vitellogenin-derived proteins (such as the β' component).
These proteins are easily bound by IgE and are resistant to digestion in the gastrointestinal tract, allowing them to transfer into the bloodstream. This is considered one of the factors that can cause reactions even with small amounts.

4) How often do cod and pollock allergies coexist?

🔗With fish roe allergies, you may react to multiple types of fish roe.
It has been shown that cross-reactions of IgE can occur between salmonid roe (such as ikura).
However, because the pattern of cross-reactivity varies from individual to individual, it is not guaranteed that "everyone will react to all fish roe."

5) Do fish roe like shishamo and sardines also require "complete set removal"?

🧩Just because someone has a fish roe allergy doesn't mean there's sufficient grounds to universally eliminate all fish roe.
The extent of elimination should be determined on a case-by-case basis, considering the presentation of symptoms and examination findings (such as specific IgE tests), with the realistic approach of limiting elimination to the minimum necessary.
Also, since there are many cases where fish meat can be consumed even with a roe allergy, it is not usually necessary to uniformly eliminate fish meat as well (individual judgment is the premise).

🔴Considering the "timing of consumption" for fish roe
When trying new foods, not just roe, the basic rule is to eat them on a day when you are feeling well, in small amounts, and during the daytime (when it's easy to get to a doctor).

Literature
Mäkinen-Kiljunen S, et al. Severe Reactions From Roe Without Concomitant Fish Allergy. Ann Allergy Asthma Immunol. 2003.
Shimizu Y, et al. Major Allergen and Its IgE Cross-Reactivity Among Salmonid Fish Roe Allergy. J Agric Food Chem. 2009.
Kyosaka I, et al. Digestibility… and Migration to Blood of β’-Component (Onk K 5), a Major Salmon Roe IgE-binding Protein. Food Chemistry. 2019.
Makita E, et al. Increased Ratio of Pollock Roe-specific IgE… Oral Food Challenge. Allergology International. 2018.
Sampson HA, et al. Food Allergy: A Practice Parameter Update-2014. J Allergy Clin Immunol. 2014.
Burks AW, et al. NIAID-sponsored 2010 Guidelines… Pediatrics. 2011.