Volume 39 | Issue 1 Article 4 1977 Allergic Inhalent Dermatitis in the Canine Michael J. Frost Iowa State University C. B. Chastain Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/iowastate_veterinarian Part of the Allergy and Immunology Commons, Dermatology Commons, and the Small or Companion Animal Medicine Commons Recommended Citation Frost, Michael J. and Chastain, C. B. (1977) "Allergic Inhalent Dermatitis in the Canine," Iowa State University Veterinarian: Vol. 39 : Iss. 1 , Article 4. Available at: https://lib.dr.iastate.edu/iowastate_veterinarian/vol39/iss1/4 This Article is brought to you for free and open access by the Journals at Iowa State University Digital Repository. It has been accepted for inclusion in Iowa State University Veterinarian by an authorized editor of Iowa State University Digital Repository. For more information, please contact [email protected]. Allergic Inhalent Dermatitis in the Canine by Michael J. Frost* c. B. Chastain, D.V.M., M.S.t Summary A dog with allergic inhalant dermatitis Allergic inhalant dermatitis (AID) is but presents a diagnostic and therapeutic one of many causes of pruritus. Ecto­ challenge to the veterinarian. The patient parasites such as Cheyletiella and Sar­ exhibits intense pruritus often accompanied coptes should always be considered as by scratching, foot licking, face rubbing, possible causes of pruritus. Contact der­ sneezing, and lacrimation. The occurrence matitis or "prickle" dermatitis from soaps, of signs is often seasonal and is usually first synthetic rugs, rug cleaners, wool products seen in the second or third year. Allergic and straw are also common causes of inhalant dermatitis is an immediate type of pruritus. Bacterial skin infections allergic hypersensitivity mediated by the manifested as superficial pyoderma, skin sensitizing antigen, IgE. The allergen, folliculitis, furunculosis or associated with or sensitizing agent, usually pollen, mold or generalized demodectic mange are also dust, enters the body via inhalation. pruritic (10). Extensive and carefully taken Allergic inhalant dermatitis has a high history and routine as well as special tests hereditary tendency and may persist for the are necessary to differentiate AID from life of the patient. Diagnosis is based on other conditions. carefully taken history, results of in­ tradermal testing, and response to therapy. Discussion Allergic inhalant dermatitis can be con­ trolled by avoidance of the allergen, by AID is a form of atopy, a term coined by medical treatment, or by biological Coca and Sulzberger in 1922 to denote a treatment. It cannot be 'cured'. familial type of allergy. Atopy is an im­ mediate type of hypersensitivity or allergic Introduction reaction seen in man and lower animals. Approximately ten percent of humans are The veterinary clinician is often atopic and dogs are presumed to be presented with pruritic patients. In fact, similarly predisposed. The percentage of most dermatologic conditions are atopic dogs \vill increase since it is a highly characterized by scratching as the earliest inheritable condition. Chamberlain (9) clinical manifestation. All too often the estimates fifteen percent of the canine clinician is tempted to resort to cor­ population to be atopic and lists no par­ ticosteroid therapy in lieu of an orderly and ticular breed predispositions. Kirk and complete diagnostic workup. Cor­ Muller (14) list breed predilections for wire­ ticosteroids will frequently provide tem­ haired terriers, Dalmations, West Highland porary relief from the itching but unless the white terriers, and poodles. Lorenz (13) primary cause is uncovered and treated lists the Dalmation, wire-haired fox terrier, specifically, the patient will continue to itch Scottish terrier, Irish setter, and poodles. when taken off steroids or will suffer the The toy and terrier breeds seem most side effects or consequences of long term commonly affected but it has been reported corticosteroid therapy. in most purebred breeds as well as in mixed breeds. *M. Frost is a senior student in veterinary medicine, AID is only one of a number of allergic Iowa State University. tDr. Chastain is an Assistant Professor, College of diseases affecting the canine, but is unique Veterinary Medicine, Iowa State University. in that the allergen is inhaled and initiates 10 Iowa State University Veterinarian an immediate hypersensitivity reaction causes antibody production and sen­ manifested clinically as a dermatitis in the sitization of the animal. Upon subsequent dog. The antigen responsible for the exposure, the allergen reacts with the allergic state is a protein with a molecular specific antibody to cause the allergic weight of 10,000 or greater. The antigen reaction. An allergic dog seems may be seasonal, including pollens of predisposed to develop allergies to things grasses, trees, flowers, weeds and which are present in his environment for a ragweed, or nonseasonal such as long time. The reaction may be seasonal at housedust, kapok, feathers, wool, and first, but as the patient ages and adds new animal danders. The antibody responsible allergies to the existing ones, the disease for the allergic reaction belongs to the IgE may progress to a continuous affliction class of immunoglobulins and is known as which makes diagnosis more difficult (14). reagin or skin sensitizing antibody. IgE is a Probably the single most important homocytotropic antibody manufactured by aspect of making an accurate diagnosis in plasma cells and bound to circulating an allergic patient is an accurate history. basophils and tissue mast cells. The Question the client about onset of itching, homocytotropic antibody has a special when it is worst, previous medications, and affinity for the skin, i. e.} skin is the target response to treatment. Inquire about the organ or "shock tissue". The respiratory patient's diet and environment, especially system and the gastric mucosa may be where he sleeps. Also find out if the owners secondary target organs in the canine themselves or any other pets itch. Ragweed allergic reaction. When the cell bound allergy in the dog was first described in antibody comes in contact with circulating 1959 by Patterson (15). antigen it causes degranulation of the mast Ragweed and other pollenoses have been cells and liberation of vasoactive amines documented by many individuals since such as histamine, serotonin, kinins and then. The National Pollen Calendar is Slow Reactive Substance (SRS), heparin, published in several texts (9,14) and and proteolytic enzymes. These in turn regional pollen guides are available from cause smooth muscle contraction, Hollister-Stier Laboratories or Center capillary dilatation, and increased Laboratories. Weekly and daily pollen capillary permeability. The clinical signs of counts are posted locally and are valuable allergy develop immediately after this in correlating the onset of pruritus with the reaction occurs and are due to the effects of pollenation of various plants. Nonseasonal the vasoactive amines and proteolytic or perennially pruritic patients are more enzymes. The early signs are edema, likely to be hypersensitive to an allergen erythema, and pruritus. The areas most found indoors such as house dust, feathers, frequently involved with swelling, redness, kapok, wool, or any materials from which and itchiness are the feet (especially household furnishings are made. If the between the toes), around the eyes, the itching starts early in the spring before ears, the groin, and the perineal area. pollenation of plants, then molds should be Secondary excoriations may be seen from suspected as the allergen. The regional scratching the chest, ears, and axillae. fauna of molds varies considerably and the Chronic paw licking may lead to reddish species indigenous to Iowa may not be discoloration of the feet in white dogs. found in other states. Mites found in house Hyperhydrosis may accompany and dust, such as Dermatophagoides spp., have enhance the itchiness and paw licking. been shown to be allergenic in the dog (9). Conjunctivitis, epiphora, blepharitis and Multiple allergies develop as the dog ages otitis are frequently observed. The signs and leads to a perennial pruritus with may commen~e within ten minutes after seasonal exacerbations (14). exposure to the allergen (15), and continue Once a tentative diagnosis of allergic until the allergen is removed from the dog's inhalant dermatitis has been made, allergy environment. - testing may be employed to confirm the For an individual to develop hyper­ diagnosis and determine the allergens sensitivity, previous exposure to the responsible. Allergy testing by itself does allergen is ess-ential. The initial exposure not provide a diagnosis, but must be Issue No.1, -1977 11 correlated with clinical signs and history. 7. Mixed epidermals (feathers, wool, and The optimal time for allergy testing is when horse, dog, and cat epidermals) the IgE, or reaginic antibody is at the 8. Extract of house dust highest concentration in tissues and clinical 9. Saline control signs are most severe. Prior to testing, the -inflammation and excoriations from These antigens were selected because they scratching should be controlled so the test are indigenous to central Iowa. They were areas are free of irritation. This must be obtained from Center Laboratories, Inc., accomplished without the use of either Port Washington, New York. A con­ corticosteroids or antihistamines. Soaking centration of 1000 protein-nitrogen