General symptoms of a food allergy

The most common symptoms of an allergic reaction may include any combination of coughing, dry itchy throat and tongue, wheezing and breathlessness, runny nose, itchy eyes, flushing of the skin, skin rash (hives) anywhere on the body, swelling of lips and throat, changes in heart rate, feeling bloated, and abdominal pain, nausea and vomiting.

Anaphylactic shock

A severe allergic reaction can be life-threatening. There are two main symptoms for this:

1. Swelling of the airways causing severe asthma and extreme breathing difficulties
2. A dramatic drop in blood pressure that can cause unconsciousness, cardiac arrest and death.

A person who experiences one or both of these symptoms, and other general symptoms as well, is said to be having an ‘anaphylactic reaction’ or to be in ‘anaphylactic shock’. In susceptible people, what starts as a seemingly slight allergic reaction, like a rash, can rapidly progress to anaphylactic shock which can kill within a matter of minutes. In some cases, and for reasons as yet unknown, there can be a delay of a few minutes to several hours between eating an allergen and that person taking an anaphylactic reaction. Food allergy is one of the principle causes of anaphylactic shock with peanut being the main culprit.

Oral allergy syndrome

In some cases an allergic reaction can be confined to the mouth, lips, tongue or throat area. Here, the symptoms, which are generally tingling and localised swelling, usually occur within one hour of eating the offending food. Oral allergy syndrome is normally associated with the consumption of fresh fruit and vegetables. Patients often complain that something is stuck in their throat but progression to a severe reaction is unlikely. People with oral allergy syndrome caused by fruit and vegetables often have an associated allergy to certain pollens and may get hay fever when these pollens are in season.

General symptoms of food intolerance

As with food allergy, the symptoms of food intolerance develop after eating or drinking particular foods. These range from mild to severe, depending on the person affected, but generally take a longer time to develop. Life-threatening intolerant reactions are very rare. Typical symptoms are abdominal pain, nausea, vomiting and diarrhoea, but can also include those more usually associated with a food allergy such as flushing, headache, hives or wheezing. 

General symptoms of coeliac condition

Gluten in wheat, rye, barley, oats, spelt and kamut triggers an immune response in coeliacs that damages the lining of the stomach and intestine. Consequently, the symptoms are primarily gastrointestinal and can range from mild to severe. These include bloating, diarrhoea, nausea, wind and constipation. However, the condition is also associated with long term health effects, particularly if the diet is not carefully managed to avoid all gluten. These symptoms include tiredness, anaemia, mouth ulcers, headaches, weight loss, hair loss, skin problems, depression, infertility, miscarriage and joint and bone pain. Coeliac condition is also a risk factor for osteoporosis and certain intestinal cancers.