Anaphylaxis, also known as anaphylactic shock, is a severe, life-threatening allergic reaction that can take place within minutes or even seconds of exposure to an allergen. Although any allergen can produce anaphylaxis, inhaled allergens rarely do. Individuals who have had allergic reactions in the past are at greater risk of anaphylaxis, particularly if such reactions have been severe. The most common causes of anaphylaxis are food allergies, allergic reactions to bee stings, and allergies to medications.
Angioedema is a swelling under the skin resulting from an allergic reaction, often occurring around the eyes or lips. Angioedema is similar to hives, although hives are more superficial. While angioedema is usually not serious and typically resolves within a few days, if it occurs in the throat or on the tongue it can interfere with breathing and be life-threatening.
Asthma is a condition in which the lungs and air passages become inflamed and constricted, interfering with normal breathing. During the first stage of an asthmatic response, inhaled allergens or other irritants cause the airways to constrict. During the second stage, there is an inflammatory response, causing the airways to swell and fill with thickened, sticky mucus. Patients with asthma have increasing difficulty breathing during an attack, often making the wheezing sound associated with the condition.
Contact dermatitis is a skin condition caused by an allergic reaction to certain materials that come into contact with the skin. A common cause of rashes, contact dermatitis appears on the skin after contact with the offending material or substance has taken place. It may occur immediately after contact or may take several days to appear. Typically, contact dermatitis presents as a red, itchy rash. While not serious medically, the condition may be very uncomfortable.
Eczema is a common skin disorder that manifests itself as itchy skin and a red rash; it is particularly common in infants and young children. Eczema most often develops as a result of an allergic reaction or an immune-system malfunction. It can cause irritation and inflammation anywhere on the body, but is especially prevalent on the face, the insides of the arms, and behind the knees. In infants with eczema, the scalp is frequently affected.
Atopic dermatitis is the most common, chronic, and severe form of eczema. It occurs most often in those with other allergic conditions, such as asthma or hay fever, and who have family members with the same issues. Eczema is not contagious even with direct skin-to-skin contact.
A food allergy is present when the immune system has an abnormal reaction to proteins in a particular food. Food-allergy symptoms, which can be triggered by ingesting even minute amounts of the food, usually happen within minutes but may, occasionally, happen a few hours later. Food allergies can begin in childhood or in adulthood, with some people suddenly having allergic responses to foods that have never caused problems. In other cases, allergies appear after a food is consumed for the first time. Certain food allergies that affect young children may eventually go away.
Hay fever, also known as allergic rhinitis, is an allergic reaction to environmental triggers that cause cold-like symptoms. Allergic reactions are triggered by exposure to certain substances known as allergens, including pollen, dust mites, animal dander, and mold or fungal spores. A physical exam will be completed by your doctor to rule out any other reason for your symptoms. Allergy testing will be done to determine the cause of your symptoms. Testing will identify the specific allergens that need to be targeted in order to begin treatment.
Hives, also called urticaria, is a common skin condition in which swollen, pale red bumps, also known as welts or wheals, suddenly break out on the skin. Hives cause itching, stinging or burning and may appear anywhere on the body. Hives are most often an allergic reaction, but sometimes the allergen precipitating the adverse reaction is unknown. Hives is never a contagious condition.
A hive may vary in size from a small dot to an area as wide as eight inches across and, in some cases, hives may combine to form larger areas known as plaques. Usually, hives last for a few hours to up to a day, before fading and disappearing. Very rarely, hives continue to be troublesome for months, in which case the condition is called chronic hives. In severe outbreaks, hives may appear on the tongue or in the throat and interfere with breathing, causing life-threatening complications. If this occurs, medical attention should be sought immediately.