Content of the material
- What Causes Allergies in Dogs
- How quickly do antihistamines work?
- Common Cold
- Are there different types of antihistamines?
- Sore Throat
- How do I take antihistamines?
- Over the Counter Medication for Dermatographic Urticaria
- Zyrtec For My Seven Year Itch
- Establishing a Treatment Plan
- Warnings and Interactions
- How do I take them?
- What happens if I stop taking antihistamines daily?
- Side effects of antihistamines
- How antihistamines work
- The Best Natural Antihistamines
- Vitamin C
- How to introduce antihistamines to your dog
What Causes Allergies in Dogs
There are many things that dogs can be allergic to and just like people, different dogs will have different allergies. If a dog is to develop an allergy, it’s likely going to be between the ages of one and three, but some dogs develop allergies when they’re as old as six as well. While most allergies are airborne, which means your dog inhales them before showing symptoms, there are other types of allergies, such as bee stings and flea bites that can also cause an allergy.
Environmental factors such as pollen, hay, and grass can cause allergies in dogs and symptoms will be present when the dog is exposed to them. This is an easy type of allergy to diagnose and treat, as a simple blood test at your veterinarian’s office will determine if an allergy is present.
If the test comes back as positive, your vet can offer an allergy shot to help treat the symptoms, or you can choose to give your pet antihistamines.
Certain food can also cause an allergic reaction in dogs, but this allergy is much more difficult to pinpoint and treat. The symptoms of this allergy can often show up as a chronic ear infection, or even feet that are constantly red instead of the usual itching and sneezing. Unfortunately, blood tests are also an ineffective way to diagnose a food allergy in dogs, so the only real treatment is an elimination diet, which could take anywhere from eight to twelve weeks.
Fleas and dust mites are the last of the most common dog allergies, and the allergy is more than just the mild itching that comes with these infestations. When a dog is actually allergic to the fleas, they are allergic to the saliva of the insect and so experience excessive itching that they can suffer from even with just one or two of the critters on their body.
Flea allergies are typically treated with topical treatments that are applied directly to the skin, but if your pet is really suffering your vet may also recommend an antihistamine that will keep them comfortable until the fleas are no longer present.
How quickly do antihistamines work?
An antihistamine tablet typically starts to work within 30 minutes after being taken. The peak of effectiveness is typically within 1-2 hours after being taken.
The common cold (viral upper respiratory tract infection) is a contagious illness that may be caused by various viruses. Symptoms include a stuffy nose, headache, cough, sore throat, and maybe a fever. Antibiotics have no effect upon the common cold, and there is no evidence that zinc and vitamin C are effective treatments.
Are there different types of antihistamines?
Generally, antihistamines have been classified into two groups:
- First-generation or sedating antihistamines can cause significant drowsiness and are generally more associated with the antimuscarinic side-effects mentioned above. These include: alimemazine, chlorphenamine, clemastine, cyproheptadine, hydroxyzine, ketotifen and promethazine. These drugs may be used for their sedative effects should your sleep be disturbed by itching.
- Non-sedating or second-generation antihistamines are newer drugs which generally cause less drowsiness. However, anyone taking these drugs while performing skilled tasks, for example driving, should be aware that a sedative effect may still occur and, in particular, in combination with alcohol. Second-generation antihistamines include: acrivastine, cetirizine, desloratadine, fexofenadine, levocetirizine, loratadine, mizolastine and rupatadine.
Sore throat (throat pain) usually is described as pain or discomfort in the throat area. A sore throat may be caused by bacterial infections, viral infections, toxins, irritants, trauma, or injury to the throat area. Common symptoms of a sore throat include a fever, cough, runny nose, hoarseness, earaches, sneezing, and body aches. Home remedies for a sore throat include warm soothing liquids and throat lozenges. OTC remedies for a sore throat include OTC pain relievers such as ibuprofen or acetaminophen. Antibiotics may be necessary for some cases of sore throat.
How do I take antihistamines?
These drugs come in a variety of forms, as mentioned above. Your doctor or pharmacist will advise you on how to take your medication, including how often. Read the leaflet that comes with your particular brand for further information.
Over the Counter Medication for Dermatographic Urticaria
by Amy (El Centro, CA)
I’ve had dermatographic urticaria for about 5 years. I am 16 years old. When I first came up with this I’d spend hours without sleeping because the itching would keep me up. I became frustrated after a couple of years of keeping up with this and not knowing what it was. Lately my friends are fascinated by it because I have “3D” skin, but the itching is never fun. I went to the dermatologist today and he told me it was dermatographic urticaria and there was an easy solution to it like an over the counter dermatographism antihistamines which can help reduce the swelling a great deal. It is working for me so far!
Zyrtec For My Seven Year Itch
I was diagnosed with dermographism when I was 21 and am now 33. I itched severly for 7 years straight and took 2-10mg Zyrtec a day (when it was a prescription and cost 4 times what it does now).
It gradually went away for a couple of years then it came back full force again and hasn’t stopped! Well the dermatographism antihistamines are cheap now so I have learned to live with this, but it is so intense that with out my meds even the water in the shower and my own hair brushing on my shoulders causes an outbreak that makes me want to jump off a building! I love my Zyrtec!
Establishing a Treatment Plan
Talk to a healthcare provider about whether an antihistamine should have a place in your asthma management plan. They'll want to consider the specific symptoms you experience and how often they occur.
A doctor may want to do a blood or skin test to confirm you have an allergy. That way, you will know which things to avoid, if possible.
They also may want to measure your lung function with spirometry. This test estimates your degree of airway constriction before and after using an inhaler.
Once the tests are complete, your asthma will be classified based on severity. This classification will influence your treatment plan and the combination of medications your doctor prescribes.
An inhaler is a prescription medication that you breathe directly into the lungs. They are essential for asthma treatment and may be short-acting or long-acting.
A rescue inhaler (Albuterol) is a short-acting medication that you use to relieve symptoms of an allergy attack. In addition to these short-acting medications, your healthcare provider may recommend long-acting controller medications if your asthma symptoms are frequent and severe. These medications include inhaled corticosteroids and leukotriene modifiers.
Inhaled medications for daily use are often unnecessary for people with mild or moderate asthma. So, talk to a doctor to see if your asthma is severe enough to warrant a long-acting medication.
A doctor will need to assess your situation to determine if antihistamines fit into your asthma treatment plan. First, they will determine which allergens trigger your asthma. Then, they will help you avoid those allergens. Finally, they will evaluate the other medications you take to see if it is safe to include antihistamines as part of your treatment plan.
Warnings and Interactions
If you take any other medications, ask a doctor to check for any interactions that antihistamines may have before taking them. Of course, it's always worth consulting with your pharmacist about this as well.
Never assume that your doctor or pharmacist knows about the medications you take. If you take any of the following medications, talk to a healthcare provider before taking antihistamines:
- Antibiotics and antifungals
- Asthma medications
- Muscle relaxants
- Pain medications
- Psychiatric medications
Research has found that central nervous system (CNS) depressants may interfere with antihistamines.Specifically, when combined with alcohol and other sedatives, hypnotics (sleeping pills), pain medications, or tranquilizers, antihistamines can reduce alertness and become dangerous. Therefore, it’s best not to combine these medications in most cases.
In addition, older adults may have an increased risk of falls and hospitalization if they combine muscle relaxants with antihistamines.
Some medications may interact with antihistamines. If you are taking any long-term or short-term medicines, be sure to tell a doctor or pharmacist before taking antihistamines.
How do I take them?
These medicines come in a variety of forms, as mentioned above. Your doctor or pharmacist will advise you on how to take your medication, including what dose and how often. Read the leaflet that comes with your particular brand for further information.
What happens if I stop taking antihistamines daily?
Side effects are rare if you abruptly discontinue antihistamines after regular use. “There are typically no rebound symptoms—it is important to keep in mind that if the antihistamine is working well and is withdrawn, there will be a recurrence of the symptoms the antihistamine was treating,” Dr. Tilles says.
If you do experience side effects after ending a daily antihistamine, they are usually mild. “Some people who use antihistamines regularly and then stop suddenly may have side effects of itchy skin and disrupted sleep,” Dr. Lin says.
Side effects of antihistamines
Like all medicines, antihistamines can cause side effects.
Side effects of antihistamines that make you drowsy can include:
- sleepiness (drowsiness) and reduced co-ordination, reaction speed and judgement – do not drive or use machinery after taking these antihistamines
- dry mouth
- blurred vision
- difficulty peeing
Side effects of non-drowsy antihistamines can include:
- dry mouth
- feeling sick
- drowsiness – although this is less common than with older types of antihistamines
Check the leaflet that comes with your medicine for a full list of possible side effects and advice about when to get medical help.
If you think your medicine has caused an unwanted side effect, you can report it through the Yellow Card Scheme.
How antihistamines work
Antihistamines block the effects of a substance called histamine in your body.
Histamine is normally released when your body detects something harmful, such as an infection. It causes blood vessels to expand and the skin to swell, which helps protect the body.
But in people with allergies, the body mistakes something harmless – such as pollen, animal hair or house dust – for a threat and produces histamine. The histamine causes an allergic reaction with unpleasant symptoms including itchy, watering eyes, a running or blocked nose, sneezing and skin rashes.
Antihistamines help stop this happening if you take them before you come into contact with the substance you’re allergic to. Or they can reduce the severity of symptoms if you take them afterwards.
The Best Natural Antihistamines
Stinging Nettle (Urtica Dioica)
Stinging nettle can be used as a natural antihistamine as it contains several different components that assist in fighting histamines.3
A randomized, double-blind study using 300 mg freeze-dried stinging nettle (Urtica dioica) in the treatment of allergic rhinitis found that the 69 patients who completed the study rated it higher than placebo in global assessments: 58 percent rated it effective in relieving their symptoms and 48 percent found it to be equally or more effective than their previous medicine.3
A 300 milligram daily of freeze dried stinging nettle is recommended for the treatment of allergens that are in the environment and some allergens that are ingested. Side effects are rare, typically allergic and gastric in nature.3
Freeze dried stinging nettle can be found in health food stores or online.
Bromelain is another natural antihistamine that you may want to add to your medicine cabinet.
Bromelain is an enzyme found in pineapple juice and in the pineapple stem.4 However, it is important to mention that pineapple itself can be a histamine trigger, thus you need to use supplements of bromelain. Bromelain supplements are available at natural food stores, vitamin shops or online.
There are mechanisms during the anti-inflammatory process that cause inflammation, swelling and pain. Bromelain is able to reverse the effects of the harmful substances, and reduce the swelling, pain and inflammation.
The therapeutic dose for allergic rhinitis ranges from 400-500 mg three times daily of an 1800-2000 m.c.u. potency bromelain. Allergic reactions may occur in those who are sensitive to pineapple. Nausea, vomiting, diarrhea are some of the unlikely side effects.3
Quercetin is another natural ingredient that can help to fight allergic reactions.
Fruits and vegetables are the primary dietary sources of quercetin, particularly citrus fruits, apples, onions, parsley, sage, tea, and red wine.5
In test tubes, quercetin prevents immune cells from releasing histamines. As a result, researchers think that quercetin can be used as a natural antihistamine and it may help reduce symptoms of allergies, including runny nose, watery eyes, hives, and swelling of the face and lips.5
It has been found to stabilize mast cells in a way that helps lower stress induced anxiety and allergic reactions.
A study conducted in The University of Tokushima Graduate School, Japan, has discovered that quercetin is able to suppress the histamine promoting gene, and aid in the antihistamine process.6
In addition, another study conducted by the Department of Clinical Analysis in Brazil, showed a decrease in respiratory distress and inflammation in airways when quercetin is used.7 Further research confirmed that quercetin also stabilizes mast cells, which lowers stress induced allergic reactions.8
It’s best to use quercetin supplements as a natural antihistamine, and not the foods that contain quercetin. The reason is that some of the foods containing quercetin may have high levels of histamines and can actually increase the allergic reaction. For example, citrus fruits contain quercetin, but can cause themselves allergic reaction in some people.
Vitamin C (also known as ascorbic acid) is a natural antihistamine and it is the most common and easiest to use in order to treat allergic reactions. There are countless foods that contain adequate amounts of vitamin C, as well as many different types of supplements available.
A study featured in the Alternative Medicine Review Journal, states that vitamin C supplementation of 2 grams daily reduced the blood histamine levels by 38%.
From this study, only minimal side effects were observed, including diarrhea and stomach distention. In general, the side effects were small to nonexistent. Researchers and natural doctors alike, suggest taking two-grams of vitamin C a day to prevent allergic reactions.9
As mentioned before, it’s best to use vitamin C supplements as a natural antihistamine, and not the foods that contain vitamin C, as some of these foods may have high levels of histamines and can actually increase the allergic reaction (for example citrus fruits).
How to introduce antihistamines to your dog
Determining if an antihistamine is working in your dog can be tricky. Not only may a specific antihistamine not work for your dog, but an antihistamine can also appear to falsely work.
For instance, you could start giving your dog an antihistamine and the allergy symptoms disappear, causing you to think that the antihistamine worked. However another reason, such as the fact that pollen season is over, could be the real reason for your dog’s suffering to come to an end. Because of this, there is a certain process to follow when introducing antihistamines to your dog.
Start by introducing the antihistamine at a time when your dog’s allergies seem to be at their worst. Most dog owners will find that this time is during the spring and the summer. If you’re unsure, ask your vet to check your dog’s medical history and look for patterns in the times that your dog’s allergies were their worst.
Once your dog has been on an antihistamine for about a month and their condition seems to have improved, stop giving it to them temporarily. If their symptoms come back, it’s a good bet that the allergies are still present but that the medication is working. If their symptoms don’t come back however, there was likely another cause for the cessation of symptoms and you may have to dig further to find out what that was.
Once your dog has been responding well to a certain antihistamine, speak to your vet about trying a different type of antihistamine. You never know, you could find one that’s even better at treating your dog’s symptoms than the one you’re currently using.
When using antihistamines for dogs, no matter what the cause of their allergy or what type you’re giving to them, it’s important to remember that the antihistamine is not a cure, but only a way to suppress the symptoms and make your pet more comfortable. And while there are many effective antihistamines available, you must always speak to a vet before administering any type of medication to your pet.