All about allergy

Authors and Editors

admin — Wed, 01 Jul 2009 12:12:15 +0000

Author: Parag A Majmudar, MD, Fellowship Co-Director, Assistant Professor, Department of Ophthalmology, Cornea and Refractive Surgery Service, Rush-Presbyterian-St Luke’s Medical Center.

Coauthor(s): Lauri Graham, Medical Writer, eMedicine.com, Inc.

Editors: Richard W Allinson, MD, Associate Professor, Division of Ophthalmology, Texas A&M University Health Science Center, Associate Professor, Department of Surgery, Scott and White Clinic; Mary L Windle, Pharm D, Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Pharmacy Editor, eMedicine.com, Inc; Robert H Graham, MD, Ophthalmologist, Robert H Graham, MD, PC; Affiliated With Department of Ophthalmology, Mayo Clinic, Scottsdale, Arizona and Carl T Hayden VA Medical Center, Phoenix, Arizona.

Allergy journal

Outlook

admin — Wed, 01 Jul 2009 12:11:33 +0000

Most people with SAC and PAC have nothing to worry about more than it being an annoying inconvenience. Although your symptoms might make the activities of daily living miserable for you, no long-term vision loss is to be expected.

Allergy journal

Prevention

admin — Wed, 01 Jul 2009 12:10:57 +0000

Unfortunately, other than avoidance of the allergen(s), PAC and SAC cannot be prevented.

Allergy journal

Next Steps

admin — Wed, 01 Jul 2009 12:10:07 +0000

Follow-up appointments are scheduled as needed.
For mild cases of PAC and SAC, annual follow-up visits with an ophthalmologist may be appropriate.
For more severe cases or for intermittent exacerbations of normally mild disease, more frequent visits with an ophthalmologist may be required.

Allergy journal

Medications

admin — Wed, 01 Jul 2009 12:09:01 +0000

Prescription eyedrops are generally very effective, and, because they are applied topically, eyedrops are usually free of many systemic side effects. Most eyedrops are used twice a day, and many can be used to prevent the allergic reaction in the first place. Some common allergy eyedrops include:
Nedocromil (Alocril)
Ketotifen (Zaditor)
Olopatadine (Patanol)
Azelastine (Optivar)
Pemirolast (Alamast)
Epinastine (Elestat)
Your ophthalmologist may prescribe cyclosporine A (Restasis). By helping to reduce the inflammatory and/or allergic reaction, cyclosporine A may help decrease your symptoms.
For more serious cases, topical ophthalmic corticosteroids can be used; however, many of the older corticosteroids are associated with ocular side effects with long-term use. The newer ophthalmic corticosteroids have a much lower risk of ocular side effects. Some common topical ophthalmic corticosteroids are:
Loteprednol 0.02% (Alrex)
Loteprednol 0.05% (Lotemax)
Prednisolone (AK-Pred)
Rimexolone (Vexol)
Medrysone (HMS)
Fluorometholone (FML, FML Forte, FML Liquifilm)

Allergy journal

Medical Treatment

admin — Wed, 01 Jul 2009 12:06:59 +0000

Numerous over-the-counter medications, such as allergy eyedrops and oral antihistamines, can be used as directed for mild allergies. In addition, many prescription eyedrops are also available to help reduce allergies.

Allergy journal

Eye Allergy Treatment

admin — Wed, 01 Jul 2009 12:06:20 +0000

Self-Care at Home
With allergies, “an ounce of prevention is worth a pound of cure.” Avoidance of the allergen(s) is the mainstay in the treatment of allergies. If you can identify and avoid the particular agent that you are allergic to, your symptoms will improve dramatically.
To further help alleviate your symptoms, you may want to try these tips for self-care at home.
Reduce the allergen load by minimizing clutter where allergens can collect.
Limit pillows, bedding, draperies, and other linens, such as dust ruffles and canopies.
Reduce the number of knickknacks that collect dust.
Minimize carpeting that can harbor dust mites.
Clean regularly and thoroughly to remove dust and mold.
Eliminate water leaks and standing water that encourage mold growth.
Use barriers and filters.
Cover mattresses and pillows with allergen impermeable covers.
Use allergen filters in both the furnace and the air conditioner in your home. Also, be sure to change them regularly.
Keep outdoor allergens outdoors by keeping windows and doors closed.
Avoid pet dander and other irritants.
Unfortunately, avoidance of the allergen(s) is not always easy or possible. In this case, the following at-home treatments may provide you with some relief from your ocular allergies.
Apply cold compresses to your eyes to help reduce the allergic reaction.
Use artificial tears/lubricating eyedrops as needed to help flush out allergens that get into your eyes.
Use over-the-counter medications, such as allergy eyedrops and oral antihistamines, as directed for mild allergies.

Allergy journal

Exams and Tests

admin — Wed, 01 Jul 2009 12:05:02 +0000

Frequently, your ophthalmologist is able to diagnose ocular allergies from your complaints alone. As part of the eye examination, your eyes are examined to help rule out other problems.
The front of your eyes are examined using a special microscope, called a slit lamp. Using the slit lamp, your ophthalmologist checks your eyes for dilated blood vessels, conjunctival swelling, and eyelid swelling, all of which are indicative of an allergic reaction.
Rarely, scraping of the conjunctiva is performed to check for eosinophils. Eosinophils are certain cells that are commonly associated with allergies; however, they are only found in the most severe cases.

Allergy journal

When to Seek Medical Care

admin — Wed, 01 Jul 2009 12:04:06 +0000

If you suffer from allergies but can identify and avoid whatever you are allergic to, your allergies should improve markedly. If you are unable to identify or avoid the allergens, seeking care for your ocular allergies from an ophthalmologist (a medical doctor who specializes in eye care and surgery) may help to make them more bearable.
If you have SAC, you may want to make an appointment with your ophthalmologist prior to the season in which you suffer from allergies in order to start treatment before your symptoms from ocular allergies begin.
If you have PAC, routine appointments with your ophthalmologist may be helpful to monitor your ocular allergies. Occasional flare-ups of your symptoms may require more frequent visits. Consultation with an allergist may be very beneficial.

Allergy journal

Eye Allergy Symptoms

admin — Wed, 01 Jul 2009 12:03:11 +0000

SAC and PAC have identical symptoms, only the timing of the symptoms is different.
With SAC, your symptoms are generally limited to a particular season (ie, spring, summer, fall).
With PAC, your symptoms probably last all year.
Almost always, the symptom of itching indicates an allergic reaction. This is true of allergic conjunctivitis, where the primary symptom is ocular itching. In addition to ocular itching, you may experience the following symptoms:
Redness
Tearing
Burning sensation
Blurred vision
Mattering and/or mucous production

Allergy journal

Eye Allergy Causes

admin — Wed, 01 Jul 2009 12:01:56 +0000

Ocular (eye) allergies often affect the conjunctiva, a clear layer of skin overlying the eyes. This clear layer of skin is the same type of skin that lines the inside surface of the nose. Because these two areas are so similar, the same allergens (substances that induce an allergic reaction) can trigger the same allergic response in both areas.
Common allergens include:
Pollen
Grass
Weeds
Dust
Pet dander
The main difference between SAC and PAC is the timing of the symptoms.
If you have SAC, you generally have problems for a short period of time.
You may be bothered in the spring by tree pollen, in the summer by grass pollen, or in the fall by weed pollen.
Generally, your symptoms resolve during other times of the year, especially in the winter.
If you have PAC, your problems probably last throughout the year.
Instead of outdoor allergens, you have problems with indoor allergens, such as dust mites, cockroaches, and pet dander.
Seasonal outdoor allergens may worsen your problems if you are sensitive to them as well.

Allergy journal

Eye Allergies Overview

admin — Wed, 01 Jul 2009 12:00:28 +0000

Up to 50 million Americans suffer from the miseries of allergies, with allergic reactions involving the eyes being a common complaint. An allergic reaction that affects the conjunctiva, a clear layer of skin overlying the eyes, is commonly referred to as allergic conjunctivitis.
Allergic conjunctivitis is divided into several major subtypes, but the most common subtypes are seasonal allergic conjunctivitis (SAC) and perennial allergic conjunctivitis (PAC). SAC and PAC are triggered by an immune reaction involving a sensitized individual and an allergen. Simply stated, this means that if you are allergic to a particular substance and then come into contact with it, you experience an allergic reaction (eg, itching, sneezing).
Although it frequently occurs, allergic conjunctivitis is most commonly seen in areas with high seasonal allergens.

Allergy journal

Authors and Editors

admin — Wed, 01 Jul 2009 11:58:03 +0000

Author: Jerry R. Balentine, DO, FACEP

Editor: Melissa Conrad Stöppler, MD

Previous contributing authors and editors: John A Calomeni, MD, JD, Consulting Staff, Department of Emergency Medicine, Seton Medical Center; Scott H Plantz, MD, FAAEM, Research Director, Assistant Professor, Department of Emergency Medicine, Mount Sinai School of Medicine; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Anthony Anker, MD, FAAEM, Attending Physician, Emergency Department, Mary Washington Hospital, Fredericksburg, VA.

Allergy journal

Outlook

admin — Wed, 01 Jul 2009 11:57:17 +0000

With appropriate and timely treatment, you can expect full recovery. With severe anaphylaxis, although rare, people may die from low blood pressure (shock) or respiratory and cardiac arrest.

Allergy journal

Prevention

admin — Wed, 01 Jul 2009 11:56:34 +0000

Strictly avoid contact with the substance (allergen) that was the trigger.
If the trigger is a food, you must learn to read food labels carefully. When ordering foods at restaurants or eating in friends’ homes, ask about ingredients. Be aware of ingredients that may contain triggers. Avoid eating foods if you can’t confirm their ingredients. If your reactions are severe, contact the manufacturer to assure that the triggering food was not processed in the same area as a food to which you are allergic.
If the trigger is a drug, inform all health care providers of the reaction. Be prepared to report what happened when you had the reaction. Wear a tag (necklace or bracelet) that identifies the allergy.
Insect stings are more difficult to avoid. Wear long-sleeved clothing outdoors. Avoid bright colors and perfumes that attract stinging insects. Use caution with sweetened beverages outdoors, such as uncovered soft drinks.
People who are likely to be re-exposed to (or are unable to avoid) an allergen that has caused them a severe anaphylactic reaction in the past should see an allergist for desensitization. Skin testing may be required to help identify the allergen.

Allergy journal

Next Steps

admin — Wed, 01 Jul 2009 11:55:39 +0000

You will usually be observed for at least six hours after the beginning of the reaction. Occasionally, a reaction will seem to get better and then recur, and even worsen, in a few hours. Sometimes the severity of the reaction will require admission to the hospital.
Upon leaving the hospital emergency department, you should immediately obtain the medication prescribed for you. You should carry these at all times to prevent another reaction or lessen its severity.
The epinephrine kit (known as EpiPen or Ana-Kit) should be kept with you at all times in case you are exposed to the antigen that caused the first reaction.
The kit contains a premeasured dose of epinephrine in an easy-to-use syringe. As soon as an exposure occurs, you immediately inject the epinephrine into your thigh muscle. This is extremely effective and fast-acting.
Anyone who has experienced an anaphylactic reaction should carry one of these kits after consulting with your physician.
Medical attention is always required right away, even if you have treated yourself with epinephrine.

Allergy journal

Medications

admin — Wed, 01 Jul 2009 11:54:42 +0000

Epinephrine – Given in severe allergic reactions, epinephrine is extremely effective and fast-acting; it acts by constricting blood vessels, which increases blood pressure, and widening the airway. Epinephrine is given by injection into the muscle, through an IV line, or by injection under the skin.
H1-receptor blockers/antihistamines – Usually diphenhydramine (Benadryl); these drugs do not stop the reaction but relieve some of the symptoms. They may be given by IV, by injection in the muscle, or by mouth
Inhaled beta-agonists (albuterol) – Used to treat bronchospasm (spasms in the lung) and dilate the airways; inhaled
H2-receptor blockers – Usually cimetidine (Tagamet); given by IV or by mouth
Corticosteroids (examples are prednisone, Solu-Medrol) – These drugs help decrease the severity and recurrence of symptoms; may be given orally, injected in muscle, or by IV line
If low blood pressure does not improve, additional medications, such as dopamine, may be given.

Allergy journal

Medical Treatment

admin — Wed, 01 Jul 2009 11:53:47 +0000

The first priority in the emergency department is to protect the airway (breathing) and maintain adequate blood pressure.
The emergency team will make sure that your airway is open and that you are getting adequate oxygen.
Oxygen may be given through tubes into the nose or by face mask.
In severe respiratory distress, mechanical ventilation may be required. In this situation, a tube is placed via the mouth into the air passages to keep the airway open. The tube is connected to a ventilator ( providing oxygen directly into the lung )
In rare cases, a simple surgery is performed to open an airway.
If blood pressure is dangerously low, medication to increase blood pressure will be given.
An intravenous (IV) catheter may be inserted
This is used to give saline solution to help boost blood pressure.
The IV line may also be used to give medication.
You may need to be admitted to the hospital for further monitoring and treatment.

Allergy journal

Severe Allergic Reaction

admin — Wed, 01 Jul 2009 11:52:23 +0000

Severe Allergic Reaction Treatment
Self-Care at Home
Do not attempt to treat severe reactions or to «wait it out» at home. Go immediately to the nearest emergency department or call an ambulance.
While waiting for the ambulance, try to stay calm.
If you can identify the cause of the reaction, prevent further exposure.
Take an antihistamine (one to two tablets or capsules of diphenhydramine [Benadryl]) if you can swallow without difficulty.
If you are wheezing or having difficulty breathing, use an inhaled bronchodilator such as albuterol (Proventil) or epinephrine (Primatene Mist) if one is available. These inhaled medications dilate the airway.
If you are feeling light-headed or faint, lie down and raise your legs higher than your head to help blood flow to your brain.
If you have been given an epinephrine kit, inject yourself as you have been instructed or have someone else perform the injection. The kit provides a premeasured dose of epinephrine, a prescription drug that rapidly reverses the most serious symptoms of anaphylaxis (see Follow-up).
Bystanders should administer CPR to a person who becomes unconscious and stops breathing or does not have a pulse.
If at all possible, you or your companions should be prepared to tell medical personnel what medications you take and your allergy history.

Allergy journal

Exams and Tests

admin — Wed, 01 Jul 2009 11:51:07 +0000

Anaphylactic reactions are diagnosed solely on the basis of signs and symptoms.
No specific tests are helpful.
Your health care provider may order tests to rule out other conditions.

Allergy journal

When to Seek Medical Care

admin — Wed, 01 Jul 2009 11:50:12 +0000

Act quickly if someone experiences the symptoms of an anaphylactic reaction. True anaphylaxis is a medical emergency and requires immediate treatment in an emergency department of a hospital, where the person can be watched closely and life-saving treatment can be given.
It is impossible to predict how severe the allergic reaction will be. Any person who shows symptoms of anaphylaxis must be transported to a hospital emergency department.
If swelling develops rapidly, particularly involving the mouth or throat, and you have trouble breathing or feel dizzy, light-headed, or faint, call 911 for ambulance transport to the hospital.
While awaiting the ambulance, administer self-treatment.

Allergy journal

Severe Allergic Reaction Symptoms

admin — Wed, 01 Jul 2009 08:36:01 +0000

The symptoms of anaphylaxis can vary. In some people, the reaction begins very slowly, but in most the symptoms appear rapidly and abruptly.
The most severe and life-threatening symptoms are difficulty breathing and loss of consciousness.
Difficulty breathing is due to swelling and/or spasm in the airways (which can include swelling of the tongue or the airways). In very rare cases, breathing can stop altogether.
Loss of consciousness is due to dangerously low blood pressure, which is called «shock.»
In the most serious cases, the heart can stop pumping altogether.
These events can lead to death from anaphylaxis.
While some symptoms are life threatening, others are merely uncomfortable. Generally, a reaction must involve at least two different body systems, such as skin and heart, to be considered anaphylaxis.
Skin: Most anaphylactic reactions involve the skin.
Hives, welts, or wheals (raised bumps): Hives can cause severe itching
Generalized erythema (redness)
Swelling in the face, eyelids, lips, tongue, throat, hands, and feet
Breathing: Swelling of the surrounding tissues narrows the airways.
Difficulty breathing, wheezing, chest tightness
Coughing, hoarseness
Nasal congestion, sneezing
Cardiovascular: Blood pressure may drop to dangerously low levels.
Rapid or irregular heart beat
Dizziness, faintness
Loss of consciousness, collapse
General
Tingling or sensation of warmth – Often the first symptom
Difficulty swallowing
Nausea, vomiting
Diarrhea, abdominal cramping, bloating
Anxiety, fear, feeling that you are going to die
Confusion

Allergy journal

Severe Allergic Reaction Causes

admin — Wed, 01 Jul 2009 08:33:41 +0000

An anaphylactic reaction occurs when the body’s immune system overreacts to an antigen, which it recognizes as an «invader» or foreign substance.
The body’s white blood cells produce substances called antibodies as a reaction to that antigen. The antibodies circulate in the bloodstream and attach themselves to certain cells in the body.
In an allergic reaction, the antibody is called immunoglobulin E, or IgE.
When the antibodies come in contact with the antigen, they signal other cells to produce certain chemicals called «mediators.» Histamine is an example of a mediator.
The effects of these mediators on organs and tissues of the body cause the symptoms of the reaction.
Triggers of anaphylaxis include many substances. Only a trace amount of the trigger may be needed to cause a severe reaction. Triggers of allergic reactions, including anaphylaxis, may include:
Prescription and over-the-counter medications (see Drug allergy)
Venom of stinging insects such as yellow jackets, bumble bees, honey bees, wasps, fire ants (see Allergy: Stinging Insect Venom)
Foods, especially high-protein foods – most commonly, shellfish, fish, nuts, fruit, wheat, milk, eggs, soy products (see Food allergy)
Food additives, such as sulfites
Transfusion of blood or blood products
Numerous other substances such as latex (natural rubber)
Dyes and contrast materials used during radiologic procedures or tests
Sometimes the trigger of the reaction is obvious – a bee sting, or a new prescription drug. Often, however, the trigger is unknown.
People with asthma, eczema, or hay fever are slightly more likely to have an anaphylactic reaction than people who do not have these conditions.

Allergy journal

Severe Allergic Reaction Overview

admin — Wed, 01 Jul 2009 08:24:19 +0000

Anaphylaxis is a severe allergic reaction that occurs rapidly and causes a life-threatening response involving the whole body. This reaction can lead to difficulty breathing and shock ultimately leading to death.
For an anaphylactic reaction to occur, you must have been exposed in the past to the substance that causes the reaction, called the antigen. This is called «sensitization.»
A bee sting, for example, may not cause an allergic reaction the first time.
Another bee sting may produce a sudden, severe allergic reaction known as anaphylaxis or anaphylactic shock.
These reactions usually occur within seconds to minutes of exposure. Occasionally, they are delayed.
You may develop sensitivity and anaphylaxis to a substance that you have been exposed to many times in the past without a reaction, and often people don’t recall the previous exposure.

Allergy journal

Authors and Editors

admin — Wed, 01 Jul 2009 08:22:09 +0000

Author: Daniel Jobe, MD, Consulting Staff, Department of Internal Medicine, Cornerstone Health Care.

Coauthor(s): Zoe Diana Draelos, MD, PA, Clinical Associate Professor, Department of Dermatology, Wake Forest University; Clinical Associate Professor, Department of Dermatology, Bowman Gray School of Medicine.

Editors: Patrick Taylor, MD, FAAEM, Medical Director, Department of Emergency Medicine, CHRISTUS St Frances Cabrini Hospital; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; James Ungar, MD, Medical Director, Chair Department of Emergency Medicine Santa Rosa Memorial Hospital; Melissa Conrad Stöppler, MD, Chief Medical Editor, eMedicineHealth.com.

Allergy journal

Outlook

admin — Wed, 01 Jul 2009 08:21:23 +0000

The rash and itching usually get better gradually and go away completely in two to three weeks. Treatment should be continued at least this long because the rash can come back if medicines are stopped too soon. You may have temporary darkening of your skin when the rash disappears.
Surrounding redness, pain, and pus can indicate a skin infection, which your doctor can treat with antibiotics. This is more likely to happen if the rash is scratched so much that the skin is broken.
You almost certainly will have another reaction if you come in contact with these plants again after a first reaction.

Allergy journal

Prevention

admin — Wed, 01 Jul 2009 08:20:38 +0000

Avoid these plants. Learn what they look like in your area. Be aware that their appearance can vary with the seasons.
Do not burn the plants. Burning can release the allergens into the air.
Wear proper clothing to protect your skin, such as gloves, long sleeves, and long pants.
Bathe pets that may have the oil on their fur. Use soapy water. Do not forget to wear protective clothing while doing this.
Wash any clothing that might contain the plant oil. Unwashed clothes can retain the oil and cause a rash in anyone who wears or handles them.
Before you go out in a potentially infested area, you can apply nonprescription products such as Ivy Block or Stokoguard, which act as a barrier to the oils.
Remember that the oil can be transferred from people, pets, or objects. Thoroughly wash anything that may carry the oil.

Allergy journal

Next Steps

admin — Wed, 01 Jul 2009 08:19:40 +0000

If you are treated by a medical professional, follow his or her recommendations exactly. Use all medications as directed.
Return to your health care provider if the symptoms do not begin to improve in two weeks.

Allergy journal

Medications

admin — Wed, 01 Jul 2009 08:18:40 +0000

Topical corticosteroid creams (prescription strength) – These reduce the immune response and relieve inflammatory symptoms.
Oral corticosteroid medication (such as prednisone) – These have effects similar to those of the creams but are needed for a more severe or widespread reaction. A course of steroids can run from three days to as long as four weeks.
Oral antihistamines – For itching. The main advantage of the prescription antihistamines is that they do not make you sleepy, allowing you to carry on your normal activities.
Antibiotics – These are needed only if the skin becomes infected after the initial rash.

Allergy journal

Medical Treatment

admin — Wed, 01 Jul 2009 08:17:22 +0000

Like most allergic reactions, treatment is dictated by the severity of the reaction. Reactions that cover a large proportion of your body, make you uncomfortable enough to disrupt your normal activities, or do not get better within a few days may require treatment with prescription medications.

Allergy journal