Allergic Reactions and Symptoms
When asked to define allergy symptoms, most people think of sneezing, sniffling and itchy eyes: the trademark features of hay fever. In fact, many other types of allergy symptoms can affect the skin, lungs, eyes and other areas of the body.
Allergy symptoms appear wherever the body releases histamine in response to an allergen. Most often, histamine is released in the skin, respiratory system or stomach. Depending on histamine levels, symptoms may range from a mild skin rash to life-threatening anaphylaxis.
Allergic Rhinitis
Most people know allergic rhinitis as hay fever: a cluster of allergic reactions occurring around the mouth, nose and face. Coughing, sneezing, a runny nose and wheezing are all common symptoms of hay fever.
The causes of allergic rhinitis vary: pollen from trees and plants, dust mites, and animal dander are all common triggers. Symptoms vary from person to person, and include a mix of the following:
coughing or sneezing
wheezing
sinus headaches
itchy eyes, mouth, ears, nose and/or throat
runny nose
sore throat.
Sinusitis and Sinus Headaches
In addition to common hay fever reactions, airborne allergens can causesinusitis. The sinus membranes become inflamed, leading to nasal congestion, sinus headaches, coughing and nasal discharge. Most cases of sinusitis last a few weeks, but chronic cases can last for months.
Asthma Symptoms
Asthma is characterized by inflammation of the respiratory airways, leading to shortness of breath, wheezing, coughing and a feeling of tightness in the chest. Many triggers can set off an asthma attack, including airborne allergens. Asthma is a potentially serious condition: check out Treatments for Asthma for more details.
Allergic Conjunctivitis
Allergic conjunctivitis is an allergic reaction of the eye. Over eighty million Americans suffer from ocular allergies. The eye usually becomes inflamed after contact with an airborne allergen. Symptoms include itchy eyes, redness, tearing and discharge from the eye.
Allergic conjunctivitis does not damage the eye, but certain forms of conjunctivitis can cause vision loss, and may be mistaken for allergic conjunctivitis. Atopic keratoconjunctivitis can cause photosensitivity (aversion to light), corneal ulcers and cataracts, if left untreated. Vernal conjunctivitis causes intense itchiness in the eye, blurry vision, a “stringy” discharge from the eye and photosensitivity. If you experience any of these symptoms, seek medical attention.
Skin Rashes and Urticaria
Skin contact with an allergen may cause a skin rash or skin hives (urticaria). A skin rash may appear as blotchy red patches or small red spots. The rash is generally confined to the area of contact with the allergen.
Skin hives are raised, itchy red bumps caused by the release of histamine in the body. They can be chronic, and may swell. Skin hives are not usually dangerous, but the sudden development of widespread urticaria is a sign of anaphylaxis, so should be taken seriously. If hives develop in the airways or on the tongue, breathing can become difficult: seek immediate medical attention if this occurs.
Eczema
Eczema is a specific skin condition with possible genetic links to allergies. People who suffer from eczema often have a family history of allergies or asthma. A scaly red rash that itches and blisters characterizes eczema. Over time, constant itching can lead to red, leathery skin. Further information on eczema is available at Treatments for Eczema.
Gastrointestinal Symptoms
Histamine can be released into the digestive system. If this happens, nausea or stomach cramps may result. Vomiting and diarrhea are also possible. Allergic reactions of the digestive system can be easily mistaken for influenza (“the flu”) or food poisoning.
Anaphylaxis
Anaphylaxis is the most dangerous of the allergic reactions. Prompt medical attention is required to prevent loss of consciousness or even death. Once an allergen is encountered, anaphylaxis can occur immediately, or begin up to an hour after initial contact. Symptoms can include:
itching and tingling of the mouth or lips
dizziness or lightheadedness
a hoarse voice
swollen lips
shortness of breath or wheezing
widespread skin hives
a sudden drop in blood pressure
a loss of consciousness.