| Hives, known in the medical literature as urticaria, are | | | | Another contributing factor to recurrent food allergies |
| a localized itchy outbreak of the skin. In this | | | | is the permeability of the intestinal wall. This is the |
| essentially allergic reaction, the skin breaks out in | | | | reason reactions to food are more severe when |
| bumps surrounded by elongated flares. These "hives" | | | | they are consumed after taking aspirin. Aspirin |
| are referred to as wheals or welts. The welts tend | | | | irritates the lining, increasing its permeability and |
| to be pink except that they turn white when | | | | easing transport of allergens into the bloodstream. |
| touched. Welts may coalesce into plaques covering | | | | Alcohol, NSAIDs, and many food additives have a |
| substantial areas of skin. | | | | similar effect. Consuming any substance that irritates |
| Hives are intensely itchy. They may involve any area | | | | the lining of the digestive tract increases the severity |
| of the body from the scalp to the soles of the feet, | | | | of the food allergy that causes hives. |
| and appear in crops of 24- to 72-hour duration. The | | | | Food colorings, especially yellow dye #5 (tartrazine), |
| most common sites for outbreaks are the hands, | | | | can provoke hives in about 0.1 percent of the |
| feet, and face. Angioedema, a swelling below the skin | | | | population. Tartrazine is added to almost every food |
| caused by the same allergic mechanism, usually | | | | and even antihistamines, antibiotics, sedatives, and |
| occurs around the eyes and in the lips. While the | | | | steroids. This yellow dye modifies fatty acid |
| itchy bumps usually go away without treatment, | | | | metabolism in the same manner as aspirin and |
| angioedema in the upper respiratory tract may be life | | | | increases the susceptibility of the skin to allergic |
| threatening and requires immediate medical attention. | | | | inflammation. |
| A survey of college students indicates about one in | | | | Food flavorings are a major factor in many cases of |
| five people has hives at some point in life. They may | | | | hives in children. A wide range of salicyclic acid esters |
| occur at any age, but young adults in their twenties | | | | flavors cake mixes, chewing gum, puddings, and soft |
| are the most frequently affected. The precise | | | | drinks. These chemical relatives of aspirin also occur |
| causes of the condition vary person to person. | | | | naturally in curry powder, dill, licorice, oregano, |
| Aspirin sensitivity is observed in up to 67 percent of | | | | paprika, peppermint, prunes, raisins, and turmeric. The |
| persons who have recurrent outbreaks of hives. | | | | average child consumes as much 200 mg of salicylate |
| Aspirin alters the metabolism of free fatty acids so | | | | per day. This dosage approaches the amount of |
| that it favors the production of leukotrienes. These | | | | salicylate in children's aspirin. Other flavorings, including |
| are hormonal messengers that make the walls of | | | | aspartame, cinnamon, menthol, and vanilla may |
| blood vessels more permeable to histamine. Aspirin | | | | produce urticaria in some individuals. |
| also makes the lining of the intestines more | | | | The food preservatives BHA (butylated |
| permeable to allergens, increasing the risk of reaction | | | | hydroxyanisol) and BHT (butylated hydroxytoluene) |
| to common food allergens such as cheese, chocolate, | | | | provoke reactions in about 15 percent of individuals |
| eggs, milk, pineapple, shellfish, and strawberries. At | | | | who have chronic hives. As many as 44 percent of |
| least one study found taking a single adult aspirin daily | | | | persons with chronic urticaria are allergic to |
| for three weeks desensitizes the immune system to | | | | benzoates, which occur in relatively high |
| aspirin and also to foods, but the benefits vanish if | | | | concentrations in fish and shrimp. Sulfites, which are |
| aspirin is discontinued. | | | | sprayed on fruits, vegetables, and shrimp to keep |
| Two factors increase the risk of outbreaks of hives | | | | them fresh in countries outside the United States, |
| after eating allergenic foods. One is incomplete | | | | aggravate a wide range of allergic conditions, including |
| digestion. A study published in the 1940's reported | | | | asthma as well as hives. Sulfites occur naturally in |
| that of 77 patients diagnosed with chronic hives, 65 | | | | beer and wine. |
| had failures to produce enough stomach acid to | | | | About 1 in 10 people is allergic to penicillin, and about 1 |
| break down the proteins that cause allergies. | | | | in 4 of those allergic to penicillin will develop urticaria, |
| Treatment with hydrochloric acid and a vitamin B | | | | angioedema, or anaphylaxis after taking it. Penicillin is |
| complex relieved symptoms in most of the patients | | | | a common additive to livestock feeds. Both skin |
| in the study. Failure to secrete sufficient gastric acid | | | | outbreaks and anaphylactic reactions have been |
| is especially common in persons over the age of 60. | | | | traced to penicillin in frozen dinners, milk, and soft |
| It may be a major contributing factor in repeated | | | | drinks. Among patients with chronic hives and an |
| outbreaks of hives after consuming allergenic foods in | | | | allergy to penicillin, about half will improve on a |
| older persons. | | | | dairy-free diet. |