Chicken Big King: Allergens at a Glance
The honest verdict
Chicken Big King · Burger King
The Chicken Big King is a double chicken patty sandwich served on a sesame seed bun with lettuce, pickles, and a mayonnaise-based special sauce. Wheat is present in both the bun and the breaded chicken patties. Milk and egg are present in the sauce and potentially in the bun. Sesame is present on the bun. Soy is present in the frying oil and sauce. Peanut, tree nut, fish, and shellfish are not typical ingredients but cross-contact via shared fryers is possible. This sandwich is different from the single-patty Original Chicken Sandwich (see original-chicken-sandwich) and the Spicy Chicken Sandwich (see spicy-chicken-sandwich). Always confirm with your specific Burger King location before ordering.
Allergen details change and vary by location. This is a general guide — always confirm with the restaurant before ordering. Not official or medical advice.
Key facts
The Chicken Big King bun is topped with sesame seeds, making sesame a direct ingredient — not just a cross-contact risk.
The special sauce on the Chicken Big King is mayonnaise-based and contains both milk and egg.
Burger King fries chicken items and fish items in shared fryers at many locations, creating a fish cross-contact risk.
Every major allergen, one clear grid
Each of the nine major allergens marked for Chicken Big King at Burger King — Contains, May contain (cross-contact or varies), or Free. Anything we couldn't confirm defaults to "may contain," because a shared kitchen can't be ruled out without the restaurant's official menu.
| Allergen and notes | Status |
|---|---|
Milk The special sauce on the Chicken Big King is mayonnaise-based and contains milk. The bun may also contain milk or butter. Some locations may use a dairy-free bun — confirm with the restaurant. | Contains |
Egg The mayonnaise-based special sauce contains egg. The breaded chicken patty coating may also contain egg as a binding agent. Egg is a standard ingredient in this sandwich. | Contains |
Wheat / Gluten Both the sesame seed bun and the breaded chicken patties contain wheat. This is the primary allergen in the Chicken Big King. There is no standard wheat-free version available at Burger King. | Contains |
Soy Refined soybean oil is used for frying the chicken patties. The special sauce may also contain soy lecithin or soy sauce. Highly refined soy oil is FDA-exempt from allergen labeling and tolerated by most with soy allergy, but those with severe soy sensitivity should confirm. | May contain |
Peanut Peanut is not a listed ingredient in the Chicken Big King or its components. Cross-contact is very unlikely in the Burger King kitchen environment. | Free |
Tree Nut Tree nuts are not an ingredient in the Chicken Big King. Not present in the bun, patties, sauce, or toppings. | Free |
Fish Burger King serves fish items (e.g., the Big Fish sandwich) that may be cooked in shared fryers with chicken patties. Trace fish protein in shared fryer oil can transfer to the chicken patties. Ask the restaurant whether chicken and fish items share fryer oil. | May contain |
Shellfish Shellfish is not an ingredient in the Chicken Big King and is not typical in Burger King fryer environments. | Free |
Sesame The bun is topped with sesame seeds. Sesame is a direct ingredient in this sandwich. For sesame allergy, request a bun without sesame seeds — though cross-contact on the bun surface is still possible. | Contains |
“May contain” means cross-contact is possible or the answer varies by location — not that the allergen is a listed ingredient. For a severe allergy, treat “may contain” the same as “contains” until the restaurant confirms otherwise.
Small changes that remove an allergen
Simple modifications that can take an allergen off your chicken big king. Always name your allergy when you order and ask staff to confirm — a modification only helps if the kitchen prepares it separately.
Order without the special sauce
Request a plain bun without sesame seeds
Ask for grilled chicken patties instead of breaded fried patties
Request a fresh batch of chicken patties cooked in a fryer not shared with fish items
A modification lowers exposure but doesn't erase cross-contact from shared fryers, grills, or prep surfaces. For a severe allergy, confirm the prep with a manager before you eat.
Read this before you order
Cross-contact & severe allergies
A “free of” mark on the grid above means the allergen isn't an ingredient — it doesn't mean the item was made in an allergen-free kitchen. Two things matter most:
Shared fryers & equipment
Shared fryers at Burger King mean the breaded chicken patties can pick up trace proteins from fish items (like the Big Fish sandwich) cooked in the same oil. The bun and toppings are assembled on shared surfaces where other allergens may be present. The special sauce is applied directly, so cross-contact risk is lower for sauce allergens. Ask staff about fryer and preparation practices at your specific location.
If your allergy is severe
For anaphylactic allergy to wheat, milk, egg, sesame, or fish, confirm fryer practices and ingredient details before ordering. The Chicken Big King is not guaranteed safe for any of these allergens without restaurant-level confirmation. Carry your epinephrine auto-injector. If you cannot confirm preparation details, consider a simpler menu item with fewer components.
This guidance is general and can't account for how any single location prepares your food. The restaurant's staff and official allergen menu are the final word — when in doubt, ask, or choose something else.
Avoidance is not the only option for milk allergy
There is no FDA-approved immunotherapy for milk allergy. Some specialist centres offer milk oral immunotherapy off-label, and Xolair is approved to reduce the severity of reactions to accidental exposure across IgE-mediated food allergies.
Beyond that, oral immunotherapy in a specialist clinic raises reaction thresholds the most of any current approach, and sublingual immunotherapy raises them less but causes markedly fewer reactions and is easier to keep up over years. Neither makes any particular dish safe to eat, and an epinephrine auto-injector stays with you throughout.
A history of anaphylaxis, or severe or poorly controlled asthma alongside the food allergy, means this belongs with an in-person allergist rather than any remote service.
Frequently Asked Questions
Yes, the special sauce is mayonnaise-based and contains milk. The bun may also contain milk or butter. For a dairy-free version, order without the special sauce and request a plain bun — though cross-contact from shared preparation surfaces is still possible. Confirm the bun ingredients with your specific Burger King location.
No. The sesame seed bun and the breaded chicken patties both contain wheat. There is no standard gluten-free version at Burger King. A grilled chicken option without breading removes the wheat from the patty, but you would still need a gluten-free bun (not standard) and confirm that the grilled chicken is prepared on separate surfaces away from breaded items.
The Chicken Big King uses two smaller breaded chicken patties stacked with lettuce, pickles, and special sauce on a sesame seed bun — similar to the Big King burger format. The Original Chicken Sandwich uses a single larger breaded chicken patty with lettuce and mayonnaise on a regular bun. Allergen profiles are similar (wheat, milk, egg, sesame), but the double-patty format of the Big King means more breading and more potential for cross-contact per serving.
The bun is topped with sesame seeds, making sesame a direct ingredient. Requesting a bun without sesame seeds may reduce the risk, but cross-contact from the bun surface and shared toaster equipment is possible. Burger King does not currently offer a sesame-free bun as a standard option. For sesame allergy, consider ordering the chicken patties alone without the bun, or choose a different menu item.
No, Burger King uses refined soybean oil for frying, not peanut oil. Peanut is not a listed ingredient in the Chicken Big King. The risk of peanut cross-contact is very low in the Burger King kitchen environment. If you have a peanut allergy, the Chicken Big King is generally considered safe by ingredient, but always confirm with the restaurant.
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Read moreFind out which foods you actually react to
Reading allergen labels is a lot easier once you know exactly what you're allergic to. Curex offers at-home allergy testing and immunotherapy so you can identify your triggers and manage them with a clinician — the confident first step before you navigate any menu.
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Please verify before ordering
Allergen info changes and varies by location
Recipes, suppliers, and preparation methods change often and differ between locations, so the details here can go out of date or not match your specific Burger King restaurant. Always confirm directly with the restaurant and check its official allergen menu before ordering. This page is a general research summary — it is not official information from Burger King, and it is not medical advice. If you have a food allergy, decisions about what is safe to eat should be made with the restaurant and, where relevant, your healthcare provider.
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