Allergies can manifest in a variety of ways. Their symptoms can include hives, sickness in the form of queasiness, red eyes and asthma. Hives are of particular interest because of their appearance. They present as reddish bumps on the skin that eventually disappear before resurfacing on a different part of the body.
Hives can be triggered by factors other than allergies. So they constitute a complex condition for which any generalizations have to be qualified. It is, however, safe to say that, when hives are triggered by an allergy, they tend to manifest shortly after exposure to the allergen, and then to eventually resolve. If one is not subsequently exposed to the allergen again, there is no reason for the symptoms to recur. Thus, avoiding the factors that one is allergic to is often an effective way to prevent recurrent bouts of allergic hives.
It sometimes takes medical tests to link hives to an allergy and to identify the precise substance to which one is allergic. A simple principle lies behind the more basic tests employed in the diagnosis of allergies like hives: Sickness symptoms that develop shortly after exposure to a substance often indicate that one is allergic to that substance.
Tests for Hives Sickness
The first step taken by allergists in diagnosing hives often involves asking their patients to keep a diary of their activities, diet and medication, beginning with the period just before their hives appeared. If a patient recently started using a new body lotion and immediately thereafter developed hives, then this would be made evident by the diary. The diary would also show how the patient reacted if he was re-exposed to the allergen or if he wasn’t exposed to it again. Simple tests would be able to confirm whether the lotion was responsible for triggering the hives. A doctor would use allergy skin testing to confirm the diagnosis of allergic hives. Sickness such as suspected urticarial vasculitis, a more serious hives-like condition, would be approached differently: instead of allergy skin testing, a doctor would opt for a skin biopsy.
When it seems likely that a patient has an allergy to a food item, then the doctor can have her take tests designed to diagnose food allergies. One of them requires the patient’s avoidance of the problem food for some time. If there are no allergy symptoms until the patient next eats the food, then an allergy diagnosis is confirmed. Another one involves trying out different foods under the doctor’s observation and seeing if they trigger hives. Sickness that develops in response to this test can be considered to confirm a food allergy.
