Allergies and Skin Diseases

Let’s talk allergies!

Allergies are so common in people and animals that a lot of the time we tend not to take seriously how bad they can really be and how sick they can make us and our pets.

We’re going to start with what allergies are and how they happen. Allergies are an immune system disease. The body makes antibodies to things it shouldn’t. Most people know about “auto-immune” diseases, where the body makes antibodies to parts of itself and how serious they can be. Allergies can be just as serious, but instead of antibodies to the self, the body makes antibodies to things in the environment (anything from grasses to pollens, fungi, molds, dust particles, dust and storage mites and even other microorganisms like bacteria and yeast), foods (usually proteins) and ectoparasites (like fleas and mosquitoes and flies). Because this is an immune system disease, it’s important to recognize that allergies are not curable. We can medically manage them in different ways so that they aren’t as severe but they never truly go away-this is because the immune system can’t ever truly go away.

Let’s break down the three different types of allergies in our pets and the different treatment options.

1. Ectoparasites

Fleas are the most common parasite allergy. All it takes is one flea bite so they don’t HAVE to have an infestation to have issues if severely allergic! In dogs, they end up creating a pretty obvious pattern: hair loss and skin irritation around the back half of the body and down the back legs. This is because the most common area fleas like to “hang out” is around the rear end (this is also why those cheap flea collars don’t really work-they don’t reach all the way back to where the fleas actually are). Flea allergies in cats is typically harder to diagnose because their allergic pattern is not as obvious. They can just be itchy all over and they can have flea allergies. The other big thing with cats is that the vast majority of the time, you won’t ever see a flea on them even with them having flea allergies. This is because they are such excellent groomers! The second they feel the flea bite them they’re going after it trying to eat it off. It also doesn’t matter whether your cat or dog is indoors only! For every adult flea, there are 99 flea eggs and those eggs are microscopic and sticky, so even you walking in and out can bring those eggs in and out of your house which can start a flea cycle. If a flea allergy is suspected, the best thing to do is to treat the environment as well as your pet. The good news is that we have quite a lot of different products that are great at keeping fleas under control (Simparica, Simparica Trio, Bravecto, Nexgard, Seresto, Revolution Plus, Advantage Multi, Advantix). If we keep the fleas under control, these pets do quite well long-term. (**there are a couple of other less common ectoparasite allergies they can develop as well: the two most common are to flies and mosquitoes. There are treatments for that as well if suspected.**)

2. Food Allergies

There is a lot of debate over how common or rare food allergies are. The general consensus is that they are typically not as common as the internet says they are. Food allergies are most commonly to PROTEINS, not grains like the internet would lead you to believe. What makes food allergies difficult, especially in dogs, is that the reaction signs can be identical in some cases to atopic or environmental allergies with the ears, belly, feet, eyes and lips affected. In cats, food allergies often present as extreme facial itchiness. So if food allergy lesions can look like atopic lesions how do we tell the difference? There are some ways food allergies can stand apart-food allergies are not seasonal, the allergy issues start for the first time when very young (around 6 months old) or older (over 5-6 years old), they’re not as responsive to our steroids/Apoquel/Cytopoint treatments. . A few common misconceptions about food allergies: a. Every food allergy animal will also have stomach issues: FALSE- there are a percentage of food allergy animals that have GI signs as well (vomiting, diarrhea, picky eating, etc) but NOT every food allergy animal has these signs; b. food allergies develop right away: FALSE- it takes quite a while for food allergies to develop, sometimes years even, so they can still develop a food allergy to a food they’ve been on for years; c. switching over the counter foods will be sufficient: FALSE, all OTC foods are made in shared factories so there is quite a bit of cross-contamination; d. food allergies can be diagnosed via blood or saliva or hair testing: FALSE, at least at this point none of these tests have proven to be accurate. The ONLY way currently to diagnose food allergies is to do a DIET TRIAL. This is where we use a prescription hydrolyzed diet (a common protein source is used but the protein is broken down into molecules too small to trigger the immune system), a prescription novel protein diet (a protein your pet has never eaten before), or a well-formulated homemade diet with a novel protein. The diet trial has to be very strictly followed and lasts anywhere from 4-12 weeks depending on the diet chosen. If your pet is doing fantastic after the trial, often we will “challenge” them with their old food to confirm a food allergy response and then what they need to eat long-term is decided together between you, the client and your veterinarian.

3. Atopic Allergies

Atopy in dogs and cats is a similar disease to eczema in people. Contact allergic reactions are the most common but inhalant allergic reactions can occur as well from allergens in the air. Animals show their itchiness and reactions through their skin-in this case the ears, feet, face, rear end/anal gland area (so similar areas to food allergies). Atopic animals tend to have seasonal flare-ups (although in some states, like Texas, where we don’t have big seasonal changes, you can’t always depend on that to help tell the difference between this and food allergies), have a strong positive response to steroids, have their first flare-up between 1-3 years of age, and *can* live a mostly indoors lifestyle. Short-term treatment can be the same across the board for all the allergy types (**see below**). Long-term treatment that is atopy specific consists of a couple of options: a. Long-term immune modulation or suppression with medications like Apoquel/Cytopoint or Atopica(Cyclosporine) or b. Immunotherapy (this is the gold standard for long-term Atopy care). This is where we figure out exactly what they are allergic to and then expose the immune system to them in a controlled way to “reset” things in a way. The testing for this can be done via a blood test (done at our clinic and sufficient for the vast majority of patients; there is a very very small percentage that make a different type of antibody that won’t be picked up on the blood testing) or via skin testing (done via a board certified dermatologist). The immunotherapy used to just come in shot form but we now have sublingual (under the tongue) drops which are much easier to give in most cases. It takes anywhere from 6-12 months for immunotherapy to really start working and this is a treatment they need to be on for years. They *can* still sometimes flare and require other medications but hopefully not nearly as often or as severe. In rare cases, their immune system can make new antibodies over time so if they are doing well for a long period of time and then start having problems again, it could be because they have developed a food allergy (there’s no reason they can’t have both unfortunately) or they’ve developed NEW allergies where we need to re-test them and re-make their immunotherapy for the new allergens. There *are* now some diets that can also help support the body, skin and immune system for atopic dogs (some examples include Purina’s Sensitive Skin and Stomach Salmon and Rice, Royal Canin Skin Support, Hills Derm Relief).

Treatment for acute flare-ups regardless of cause:

Whether it’s from ectoparasites, food, or atopy, when an allergic reaction happens, there is inflammation, itching, chewing, licking, rubbing, and generally feeling terrible. They can then develop secondary infections (bacterial, yeast/Malassezia or a combination of the two) which also trigger the same symptoms leading to a vicious cycle of misery. Bacterial infections require antibiotics (that can include oral antibiotics and/or antibiotics in topical forms meds/shampoos/sprays/mousses/wipes/etc). Fungal infections require antifungals (in the same forms as antibiotics). The allergic reaction itself also needs to be treated and this can be done by using steroids (whether oral with things like Prednisone or topical with steroid creams/sprays/mousses/wipes/shampoos) or anti-itch injections (like the monoclonal antibody Cytopoint or the immune-modulator Apoquel and sometimes a combination of these. Usually, treatment is multi-modal to reach the best results. Keep in mind that the skin is one of the slowest organ systems of the body so it may take weeks in severe infection cases to completely heal and bringing your pet in for their recheck appointments is critically important (**antibiotic resistance is a serious problem and it is vital to make sure we’re getting rid of a bacterial infection instead of just knocking it down to low numbers**).

Other things you can do that may help:

1. Antihistamines

2. Omega 3 Fatty Acids (Fish Oil)

3. Routine bathing and skin maintenance: in the case of atopy, since contact allergens are the main source, wiping their skin down often and bathing them more often than you would a pet with normal skin. Talk to your veterinarian about the best shampoo options and how often to bathe your pet.

4. If you are interested in integrative treatments (herbal formulas), ask Dr. Rachal for more details on these.

5. Address any other underlying diseases that can make allergies worse or check to make sure you aren’t dealing with something else instead: this can be things like mites (Sarcoptes, demodex), hypothyroidism, Cushing’s disease, ringworm, autoimmune skin diseases, skin neoplasias, etc.

Our goal is to work as a team taking all of this information into account to come up with the best game plan for your personal pet, as each one is different even if their allergies may be the same. For more information or to take the steps needed to help your pet feel their best when their skin is the worst, reach out to our team for an appointment!