[A dog related Demodex spp. infestation in a student: a rare Demodex case]

Demodicosis is an ectoparasitic cutaneous infestation of pilosebaceous unit caused by Demodex mites. Demodex spp. are considered to be pathogenic when they increase in number and infect dermis.They can be the cause of diseases such as pityriasis folliculorum, papulopustular rosacea, granulomatous rosacea, inflammatory papule, acne vulgaris, perioral dermatitis, blepharitis and folliculitis. These mites can be found in most mammals including human. Canine and feline demodicosis is a well-known example of severe dermatitis caused by the proliferation of Demodex mites. Dogs are one of the most popular pets worldwide with well-being feeling to their owners. However, they may cause a health risk to humans due to their zoonotic diseases potential. Demodicosis is a severe and prevalent dermatologic disease in dogs. In this case report, a Demodex case thought to be related with a dog infestation was presented. A twenty-year-old girl student who feeds a Miniature Pinscher crossbred dog in her house for a while noticed common itchy papulopustular lesions, incrustation and some alopecic loci in her dog and admitted to Selçuk University Faculty of Veterinary Medicine, Department of Parasitology. Itchy papules and pustules were also observed in dog's owner face and arm about three or four weeks later. Skin scrapings and hair samples were taken from the patient and the dog and examined with light microscope. Adult and egg forms of Demodex spp. were detected in both patient and dog specimens in microscopic examination. Ivermectin treatment was recommended as 0.2 mg/kg for the dog. The owner of the dog was sent to a dermatology clinic and topical permethrin was recommended for the treatment. At the end of the first month the dog was controlled again, a whole clinical and microscopic improvement was observed and all of the lesions were disappeared for both the dog and its owner. This demodicosis case, thought to originate from a dog, is a rare condition because of Demodex mites are known to be highly host specific and not a zoonotic parasite. Although host specific cross infections between humans and animals have been rarely reported, D. canis was determined to be more transmissible across species than the other Demodex mites as indicated in the literature. As a result, it is necessary and important to keep in mind about Demodex spp. infestation in patients with skin complaints and pet feeding.