Dermatologic Disorders, Allergies, and Atopy
Alternative Therapies for Atopy
Dogs with atopic dermatitis (AD) often have concurrent allergies and are prone to relapsing skin and ear infections, which significantly contribute to their discomfort level. Much research has been done in recent years to identify effective and safe alternative treatments.
Percutaneous absorption of allergens may be the most relevant route of exposure in dogs. Topical therapy may reduce the amount of allergen absorption through the skin. Several preparations, including glucocorticoids and anesthetics, can be used to reduce pruritus and provide analgesia.
Cyclosporine, misoprostol, pentoxifylline, and various antihistamines have been effective.
Compendium 2001 May 23(5):454-60
Tetracycline/Niacinamide for Dermatology
The combination of tetracycline and niacinamide is being used for a continually expanding list of dermatologic disorders thought to be of immune-mediated origin. Diseases that may be controlled with this combination include discoid lupus erythematosus, pemphigus erythematosus, vesicular cutaneous lupus erythematosus (idiopathic ulcerative dermatosis) in Collies and Shetland Sheepdogs, pemphigus foliaceus, lupoid onychodystrophy, metatarsal fistulae in German Shepherds, sterile panniculitis, sterile granulomatous/pyogranulomatous dermatitis, vasculitis, cutaneous histiocytosis, idiopathic lymphocytic/plasmacytic ear margin dermatitis, and nodular granulomatous episcleral keratitis.
Antihistamines in Horses
Practitioners may prefer to use antihistamines to reduce urticarial reactions and reduce pruritus in horses because these drugs usually have fewer side effects than steroids. The American Quarter Horse Association recommends a 10 day withdrawal prior to any competition.
Vet Prac News, Apr 2001
Prednisone Administered as a Transdermal Gel to Treat Allergic Dermatitis in a Cat
A 5 y.o. female feline presented with allergic dermatitis accompanied by severe scratching and hair loss. The cat had previously been treated with oral prednisone tablets. As the owner was unable to “pill the cat," she had tried to crush the tablets and mix with milk or tuna juice, but the cat still would not take the medication.
It has been our experience that transdermal gels work wonderfully in cats. An owner does not have to fight the animal to get a tablet down the cat’s throat, and does not have to worry about whether the animal has received the correct dose, as the prescribed amount of gel can be massaged into the vascular surface inside the cat’s ear.
The veterinarian prescribed Prednisone 5 mg/0.1 ml in a transdermal gel. We dispensed 3 ml, with instructions to apply 0.1 ml (5 mg) daily to the inside of the cat’s ear. The benefits of transdermal administration include the ability to reliably administer the prescribed dose, and ease of administration to a calm, relaxed cat.
The therapy was very successful. The cat’s dermatitis resolved and the hair began to regrow within a few weeks. There were no complications and no modification in dosage was necessary. The owner periodically uses the preparation when she first notices signs of a relapse. Relapses have promptly resolved with transdermal prednisone therapy.
Janna L. Love, Pharm.D