How can a seafood allergy be managed?

The best management for any food allergy is simply to avoid the food you are allergic to, and a seafood allergy is no exception. Fortunately, avoiding seafood is not particularly difficult, as it is not usually used as an additional and unexpected ingredient in many foods. When eating out, you might need to make sure that other foods have not had any contact with your allergen (for example, chips cooked in the same oil as fish may trigger an allergic reaction).

You can get medications for the asthma-like symptoms and the allergic rhinitis and allergic conjunctivitis that you may have problems with if you breathe in seafood vapours. You can buy antihistamine tablets and nasal sprays over the counter. Medications for symptoms of asthma will need to be prescribed to you by your doctor. The type of medication you will need, and how often you will need to take it, depends on the severity of your symptoms.

Antihistamine tablets are a common and popular choice. They include loratadine or cetirizine hydrochloride. Most of these tablets are once-a-day tablets, and are effective against a wide range of symptoms. You can buy these over the counter at any pharmacy.

Nasal symptoms can be treated with nasal sprays. These come in many varieties.

Decongestant nasal sprays simply clear out a blocked nose. Examples of a decongestant nasal spray include ephedrine, phenylpropanolamine, or phenylephrine. They work by acting on the nervous system to narrow the blood vessels in your nose (vasoconstriction), which can make a nose less blocked and also help reduce the amount of mucus. Remember that a blocked nose is mainly the result of blood vessels in the wall separating the two sides of your nose (your nasal septum) becoming wider (vasodilation). Decongestant nasal sprays can clear your nose before you use another type of nasal spray – this makes the other nasal sprays more effective. Care must be taken that you do not over-use these, as this can result in a blocked nose which was worse than it was to begin with after you stop using these sprays.

Antihistamine nasal sprays are also readily available. Examples of antihistamines are cetirizine or loratadine. Antihistamines work by acting against histamine receptors and thus stopping histamine giving you symptoms. Histamine is a chemical that is released from mast cells when allergens are present, and their effects on the body produce the signs and symptoms of allergy. Steroids, such as beclometasone dipropionate (Beconase), can also be found as nasal sprays, and these work by stopping the production of chemicals known as leukotrienes and prostraglandins, which can contribute to the symptoms of allergy. Leukotriene antagonists, such as montelukast and zafirlukast, act against leukotrienes. They have fewer side effects that steroids, but are also less effective.

Symptoms of allergic conjunctivitis can be relieved by eye drops. As with nasal sprays, there are several different types. Eye drops can include antihistamines such as cetirizine hydrochloride. Antihistamine eye drops can be effective within 10 – 15 minutes. You can also find eye drops which are used for rehydrating the eye and providing relief from itchy or dried eyes. These are more expensive and should not be used too often, as you may get a rebound reaction where the eye ends up drier than what it was before you used these eye drops. Sodium cromoglicate and nedocromil act by stabilising the mast cells (these cells release histamine) and can stop histamine being released. These drugs can be extremely effective. It is important that you do not wear contact lenses while you are using eye drops.

Asthma-like symptoms can be relieved by inhalers, however, inhalers are only given out by prescription. You can see your doctor if you need to obtain an inhaler.

You are most likely to be given the “blue” inhaler first. This is likely to contain terbutaline or salbutamol, which are beta-2 adrenergic agonists. This means they act on the nervous system to relax the muscles around your airways and allow your airways to open up again. One puff of this inhaler should be taken whenever necessary, and the effects can last 3 – 4 hours.

If you still require more medication for symptoms of asthma, you may be given the “brown” inhaler. This contains a corticosteroid, which stops some important immune chemicals being produced (these chemicals are leukotrienes and prostraglandins). These chemicals can worsen symptoms by making blood vessels wider (vasodilation) and leaky, and can attract other white blood cells to the area, making symptoms worse. Examples of corticosteroids used for treating asthma symptoms are beclometasone dipropionate and budesonide. These drugs should be taken twice a day, and you should continue using the blue inhaler as needed.

If you still require medication, your doctor will assess how well you are doing and may decide to add a long-acting beta-2 adrenergic agonist to your plan. This group includes drugs like salmeterol and formoterol, and are the “green” inhalers. They provide relief for approximately 12 hours. You should still continue using the brown and blue inhalers as directed too. The effects of the green inhaler can last the whole night and might be the key to a good night's sleep if your symptoms are severe.

If this is still ineffective, your doctor may change the dosage of your brown inhaler, and may also decide to give you other drugs. One class of these other drugs are leukotriene receptor antagonists. These drugs stop additional white blood cells being drawn to the area, and have fewer side effects than steroid drugs. Examples of leukotriene receptor antagonists are montelukast and zafirlukast. Alternatively, you might be given theophylline in a tablet form, which can relax the muscles around your airways and open up your airways. If your asthma symptoms continue to be troublesome, you may be given corticosteroid tablets too.

Always carry your EpiPen with you when you are out, if you have been given one. Anaphylactic shock can be fatal and the adrenaline from an EpiPen can save your life. You might also wear a bracelet or some other form of identifier to indicate that you are allergic to seafood.

Seafood allergies Guide Index:

• What are seafood allergies?
• What are the signs and symptoms of a seafood allergy?

• How can a seafood allergy be diagnosed?
• How can a seafood allergy be managed?