Dermatology - Demodicosis Flashcards
(76 cards)
What mites cause demodicosis in dogs and which is the most common?
Demodex canis (common) and Demodex injai
What mites cause demodicosis in cats and which is the most common?
Demodex cati and Demodex gatoi (common)
Where does the life cycle of D. canis, injai, and cati occur?
the entire life cycle is completed in the hair follicle of the host
Where does the life cycle of D. gatoi occur?
in the outer layers of the stratum corneum
What are the stages of the Demodex lifecycle?
egg, larva, nymph, adult
How is Demodex canis acquired?
They are considered natural inhabitants of the skin, but they proliferate during pregnancy and thus are transmitted at birth
Which species of Demodex is thought to proliferate due to a genetic predisposition?
Demodex canis
How do Demodex affect the immune system?
they suppress it leading to secondary bacterial and fungal infections - the patients becaume an immunologic cripple
What may predispose an animal to infection with Demodex?
any immunodeficiency syndrome
What Demodex species is spread by direct contact?
Demodex gatoi
What are the two types of demodicosis caused by Demodex canis?
Localized and generalized
What age dogs is generalized demodicosis more common in?
dogs less than a year of age
Where is localized demodicosis commonly seen?
on the forelimbs, face, and on periocular skin
What does localized demodicosis typically look like?
Well circumscribed areas of alopecia with mild scaling and erythema confined to one body area
What form of demodicosis does not typically have secondary problems associated with it?
localized
True or False: 90% of lesions due to generalized demodicosis will spontaneously resolve, 10% will not
False - 90% of the lesions in localized cases will resolve and 10% will become generalized
What areas of the body are typically involved in cases of generalized demodicosis?
the face, forelimbs, and feet
What lesions are typically associated with generalized demodicosis?
Lesions include generalized erythema, crusting, scaling, and patchy to diffuse alopecia, sometimes with bluish or bruised appearance
What secondary infections (lesions) are commonly associated with generalized demodicosis?
Folliculitis and furunculosis, leading to the development of papules, pustules, and fistulous tracts. Staphylococci are the most common agents isolated
Other than skin lesions, what other secondary complications are associated with generalized demodicosis?
Anorexia, pyrexia, and depression; generalized lymphadenopathy is present
Is pruritis associated with generalized demodicosis?
It is absent or mild unless there is secondary infection - then it is moderately intense
What is adult-onset demodicosis defined as?
onset of generalized demodicosis after 1-2 years of age
What conditions is adult-onset demodicosis associated with?
Immunosuppressive disorders, such as hyperadrenocorticism, hypothyroidism, organ failure, etc, and systemic administration of glucocorticoids
Where, on the body, are Demodex injai typically found?
over the dorsal midline, often in animals under stress
