Can You Identify An Allergy To Shellfish?

Over recent years the levels of fish and seafood consumption has increased dramatically, partly due to the concerns about fat and cholesterol in our diets. Because fish is seen as the healthier and low fat option, people are choosing it far more over red meat – it also offers bountiful doses of heart-healthy omega-3 fatty acids, which is an added bonus to our health. As this has increased, so too have the numbers of people who are allergic to it. Fish allergies affect around one in 200 people, and shellfish allergy symptoms  (such as prawns and crabs) are more common with one percent of the population in significant shellfish consumptions. A seafood allergy is more common amongst adults than children, and isn’t as common as milk or peanut allergies. Those who have an allergy to this form of food tend to have it for the rest of their lives. But how can you spot it?

As with other foods, the symptoms include nausea and sickness, abdominal cramps, wheezing, flushing or swelling of the skin, urticarial rashes and diarrhoea, and even fatalities in some extreme cases. It’s fairly uncommon for people to have an allergic reaction to just the smell of a food, though many people complain of such a symptom. However, in shellfish allergies, this is not the case – around 15 percent of people with a seafood allergy can react just to vapours and steam produced during cooking, in particular with BBQ and grilling. This is a chemical reaction, as fish and shellfish release small proteins known as amines during cooking, which lead to people inhaling them. This causes a reaction that’s quite unlike other food allergies. Surveys suggest that after nut allergies, seafood is the most common for severe reactions, known as anaphylaxis. In a report based on 167 children with seafood allergies, over one in five had experienced a severe reaction to the food.

Most people with allergies to crustaceans, such as prawns, are still able to eat finned fish. Similarly, people who are allergic to tuna can often eat prawns – a cross-reactivity within a class is common, though, for some people who are allergic to a fish such as salmon generally have to avoid all finned fish. This is the same for people with a crustacean-allergy when eating oysters and squid, as studies suggest that there could be cross-sensitivity with these foods. This cross-reactivity tends to be more common in children than adults – it’s for this reason that children with seafood allergies need an allergy assessment in order to determine which other forms of fish and shellfish that are allergic to and need to avoid.

If you notice that you get symptoms akin to other allergies when fish or seafood is cooking, this can be a sign, as previously mentioned. Patients with a long history of severe reactions to crustacea should avoid locations where these foods are cooked and served, as it can trigger allergic reactions which could prove to be fatal in severe cases. Interestingly, reports suggest that up to 20 percent of people who are allergic to fish can tolerate it when it is canned, such as tuna. The canning process involves extensive heating in order to preserve the food, which can destroy the protein that many are allergic to. However, it’s not worth risking it as four out of five people will still have a reaction. If you suspect you may have an allergy to fish or shellfish, it’s worth speaking to your GP in order to determine if this is the case. You may require an allergy testing in order to diagnose it.

Categories: diet, food allergy, intolerance

Milk Allergy or Intolerance: What"s The Difference?

We often hear remarks about milk and dairy intolerances, but what is the difference between an allergy and an intolerance? Is one more serious than the other, and how can you identify between the two? A milk allergy is when your baby’s immune system reacts to the proteins in milk – this is commonly a childhood allergy and affects around two percent and seven percent of infants. If your baby has eczema, they’ll be more likely to develop an allergy to milk. A lactose intolerance, however, occurs when your baby can’t digest the lactose, or sugars, found in milk. This is rarer than an allergy and isn’t necessarily confined to childhood. Your baby can consume milk proteins through your breast milk if you’ve drunk or eaten dairy produce, or they may react to milk formulas which are made up of cow’s milk. Babies are sometimes allergic to the casein in milk, which is the curd which forms when the milk turns sour; they may be allergic to the whey, which is the watery substance which is leftover when the curd is removed; they may sometimes be allergic to both. If your child has an allergy to milk, they’ll often have outgrown it by their teenage years – some even by the age of three. However, around half of babies and children who have a reaction to milk will develop an allergy to something else later in life. Studies show that around 80 percent will develop asthma.

Some children or infants have immediate reactions after drinking milk or having eaten dairy, which could show up as a flushed face, a rash on the skin, or watery eyes and a runny nose. They may feel sick, vomit or have diarrhoea, or in extreme cases have anaphylaxis – an extreme and rare reaction to an allergen. A simple skin prick test or a blood test can help determine if there are any allergies in your children. Though most reactions are immediately obvious, delayed allergic reactions are not uncommon either. This may arise in the form of eczema, colic, constipation or diarrhoea, or failure to gain weight – also referred to as a failure to thrive. These symptoms are common in early childhood though, and a milk protein allergy is just one possible explanation. It’s for this reason that getting your child tested if you suspect an allergy is important, in order to determine if this is actually the case. Delayed reactions make diagnosing the condition more difficult, as they involve parts of the immune system which are slower to respond.

Your GP or a dietician can work through a diet plan with you which will involve cutting out milk and dairy to see if the symptoms disappear or resurface. However, before cutting anything from your child’s diet, speak to a GP first to check it is safe. This is the same if you suspect your child is allergic to the formula you’re feeding them – get medical advice beforehand, as it may not be as simple as simply switching to a soya-based product. A lactose intolerance is quite different to an allergy in that your baby will not have the enzyme, lactase, they need to break down lactose found in dairy products. This is rare amongst babies in the UK, but it doesn’t happen. It tends to occur in places where adults don’t typically drink or cook with cow’s milk, such as in Asia. As before, speak to your GP if you suspect this is the case who can run tests and identify the problem.

Categories: allergies, intolerance, milk