In many patients who suffer from allergies, the reaction progresses into a series of late response allergic reactions. It is estimated that as many as 50% of allergy sufferers experience late response reactions after being exposed to an allergen. These responses typically become apparent in the hours or days following an acute reaction to an allergen. They commonly contribute to on-going symptoms, and in some patients, they make the body more susceptible to future exposure.
The body initially responds to an allergen within minutes, causing common symptoms like coughing, sneezing, runny nose, and congestion. This occurs when the receptors inside mast cells bond with the antibodies that are involved in allergic reactions. When this occurs, the mast cells break open and release chemicals like histamine that cause allergic responses. After histamine is released, the mast cells continue to release other chemicals that attract inflammatory cells. This is what causes late response allergic reactions.
Symptoms of Late Response Allergic Reactions
Late response allergic reactions are largely characterized by swelling. Common symptoms include nasal congestion and blockages caused by inflammation, puffy eyes, sleep disturbances, and general feelings of congestion and grogginess. These symptoms take longer to develop, and they can last for up to 24 hours after initial exposure. As a result, they often contribute to chronic problems to environmental allergens like pollen that allergy sufferers may be exposed to on a regular basis.
Treating Late Response Allergic Reactions
While antihistamines are often prescribed to treat the symptoms of acute reactions, they are not helpful in treating late response allergic reactions. As a result, patients who suffer from late response reactions typically need to take different medications such as anti-inflammatory drugs or bronchial dilators. Some patients may also undergo immunotherapy to become desensitized to certain allergens. When late response allergic reactions are caused by a particular allergen that can be identified and avoided such as pet dander or certain foods, patients can usually prevent exposure by avoiding the particular allergen.
In most cases, allergies and late response allergic reactions can be managed without major complications. By determining the exact cause of an allergy through the use of various allergy testing methods, doctors can prescribe medications or lifestyle changes that will allow patients to mange the symptoms of both acute and late response allergic reactions. Late response reactions typically are not life-threatening as some acute responses may be, however they may make patients more susceptible to future acute allergic reactions.