Dermatology Part 2 Flashcards
A 2 year old mixed breed dog presents to you for chronic ear infections. His rDVM has been treating bilateral ear infections since this dog is 6 months old. What underlying condition are you concerned could be causing this?
Atopic dermatitis (Allergies)
A 14 year old cat presents to you for head shaking and pawing at his ear. The owner says he has also had some ear discharge in his left ear and now his left eye is squinting. What is your first thought?
He has a mass or a foreign body in his ear
You look into an ear with an otoscope. What parts can you see?
The vertical and horizontal canals to the tympanic membrane
If you can’t see the tympanic membrane what drugs can you safely give into the ear for an infection
sterile water, squalene, Tris-EDTA
What parts of the ear do you need a CT/MRI to visualize
the inner ear and middle ear
If a cat has a middle ear infection, what part of his anatomy makes it difficult to treat
the bony septum that spilts the bulla into two parts
A human doctor recommends to you that you do a Kirby-Bauer test before you give his dog antibiotics for his ear infection. Do you agree?
No, because the topical antibiotics will reach much higher concentrations that what is reported in the test
What do you recommend using to monitor a patients ear infection to see if he is getting better
Frequent cytologies to monitor progress
Is radiology a good (sensitive) test for visualizing ear infections
no, CT and MRI are better
What are four antibiotics in medicated ear drops
Gentamicin, Polymyxin B, Neomycin, Amikacin
What seems to differ in the ears of allergic and healthy dogs?
There is a microbe shift and usually an overgrowth of one type of bacteria. Healthy ears are balanced with a microbiome of many types of bacteria growing all in small amounts/ controlling the growth of one another
Name a few predisposing factors
Brachycephalic, Excessive hair, pendulous pinnae, frequent ear cleanings
Name some primary factors
atopic dermatitis, parasites, foreign bodies, masses, endocrinopathies
Name some secondary factors
otitis media, bacteria, yeast, chronic pathologic changes, fibrosis, stenosis, mineralization
What are some signs of otitis media
none or fever, anorexia, pain when opening mouth, facial paralysis, Horner’s, hearing loss
What are some signs of otitis interna
hearing loss, peripheral vestibular disease, nystagmus,–> damage to vestibulochoclear nerve
What will you see on a histopathology of a pemphigus foliaceous case
acantholytic keratinocytes and no microbes
What is unique immunologically with pemphigus folliaceous cases in terms of auto-antibodies
they have IgG, IgM, IgA, NO IgE
What are the primary lesions with pemphigus, what about secondary?
Pustules–> crusts, erosions, erythema
A dog presents with crusts on his nose and ear flaps and has lost cobblestone appearance and pigment on his nose. He also has lesions on his footpads. What disease are you concerned about
Pemphigus Folliaceous
A dog has pustules, what are your 3 differentials
pemphigus, pyoderma, dermatophytosis
You are treating a dog with antibiotics for pustules, but he hasn’t improved in a week. You do a cytology and there are no microbes on it. What disease may he have
Pemphigus Folliaceous
What symptoms are unique to cats with Pemphigus Folliaceous
pustules on the nail folds
What animal does not have puritis when it gets pemphigus`
goats
What are two possible causes for pemphigus in dogs
idiopathic or drug induced
What is the autoantibody target pemphigus goes after
desmocollin 1
What two pemphigus varieties are most severe/ not benign. Where is a unique place these diseases have ulcers?
P. vulgaris and Paraneoplastic pemphigus and they have oral ulcers
Which pemphigus does not have suprabasilar pustules/clefts and what does it attack in the skin
P. erythematosus and it attaches the subcorneal space with lichenoid interface dermatitis