Path 1- Integument 5

drraythe's version from 2015-05-01 15:14


Question Answer
Mycobacterium tuberculosis & Mycobacterium bovis more commonly cause? (What dzs w/ what lesions)Alimentary & pulmonary dz w/ rare cutaneous lesions
Mycobacterium lepraemurium causes what? & is transmitted how?Feline leprosy & is often transmitted via bite wounds from rats or other cats
Mycobacteriosis is caused by what?Opportunistic pathogens
Numerous saprophytic Mycobacterium sp can cause infxn through what method?Through wound contamination
Non-mycobacterial granulomas are classified into what 2 categories?(1) Non-filamentous bacterial granulomas (Botryomycosis)
(2) Filamentous bacterial granulomas (Nocardia sp., Actinomyces sp., Streptomyces sp)
Idiopathic granulomatous dermatitis (non-infectious) are split into what 2 categories?(1) Sterile granuloma & pyogranuloma syndrome
(2) Juvenile sterile granulomatous dermatitis & lymphadenitis (Juvenile cellulitis, Juvenile pyoderma, Puppy strangles)
When should you consider a sterile granuloma complex?Sterile granuloma complex should be considered as a differential Dx AFTER attempts have been made to rule out infectious etiologies (biopsy w/ histopathology & bacterial culture)
Sterile granuloma & pyogranuloma syndrome → Who is this common in? What are the gross lesions?Common in DOGS. The gross lesions are: single or multifocal papules, plaques or nodules most commonly occurring on the head & extremities
**Juvenile Sterile Granulomatous Dermatitis & Lymphadenitis → WHO does this occur in? What are the lesions like? What systems are involved & what is the pathogenesis?Occurs in puppies <4mo. Similar lesions as sterile granuloma & pyogranuloma syndrome (single or multifocal papules, plaques or nodules most commonly occurring on the head & extremities) & there is involvement of the LNs. UNKNOWN PATHOGENESIS
**Systemic bacterial infxn & sepsis can lead to skin lesions by 4 mechanisms affecting blood vessels → WHAT ARE THEY?(1) Bacterial embolization
(2) Bacterial toxins
(3) Direct infxn of vascular endothelial cells
(4) Immune-complex vasculitis (Type III hypersensitivity)
Erysipelothrix rhusiopathiae creates skin lesions HOW? aka? Lesions via bacterial embolization resulting in vasculitis, thrombosis & infarction. (aka Diamond skin dz)
Septicemic salmonellosis causes skin lesions, how?Endotoxin-induced venous thrombosis leading to cyanosis & necrosis of distal extremities. (SalmoNella eNdo toxin—only ENDO toxin & only etiological agent w/ N!)
Escherichia coli causes skin lesions how?Production of Shiga toxin 2 leads to endothelial dmg, vasculitis & resultant edema dz of pigs
Staphylococcus aureus causes skin lesions how?Production of exotoxin! That act as superantigens causing a condition in dogs similar to toxic shock syndrome
Streptococcus canis causes skin lesions how?Produce exotoxin! That contribute to vascular dmg in necrotizing fasciitis
Rickettsia rickettsia (the agent of what?) causes skin lesions how?The agent of Rocky Mountain Spotted Fever. Directly infects endothelial cells leading to vasculitis & necrotic skin lesions

Lecture 7

Question Answer
Superficial Mycoses → How are they superficial?Infxns are restricted to the stratum corneum &/or hair shaft
Trichosporon beigelii causes what, in who? How severe is this?Causes a very mild condition known as piedra, or trichosporosis, or trichomycosis nodularis, which causes swelling of extrafollicular hair shaft. Happens in humans, dogs & horses & is mostly just a cosmetic problem
Cutaneous Mycoses is a fungal infxn of what?Fungal infxn of the hair follicles, claws & epidermis
Dermatophytosis is aka? Common in who? Which age is most susceptible?(Aka Ringworm) common in CATS & YOUNG animals are more susceptible
Dermatophytosis is usually caused by what 2 organisms? Where do these organisms colonize? What is the clinical dz caused by?(Ringworm) Microsporum sp., Trichophyton sp.. Dermatophytes colonize the cornified structures (hair, s. corneum). Clinical dz is caused by the host’s immune rxn!
What are the gross lesions of dermatophytosis? Histologic features?Gross: circular to irregular, scaly to crusty patches of alopecia. Histologic: perifolliculitis & luminal folliculitis w/ occasional furunculosis & epidermal hyperplasia
Candidiasis is caused by what? When does this infxn occur?Caused by Candida sp. which are yeast that are normal inhabitants of the skin & GI tract. Infxn occurs when host resistance is compromised or when the normal microflora is disrupted
What are the gross lesions of Candidiasis?Exudative & fibrinous cheilitis, stomatitis, esophagitis & otitis externa (Histologic lesions: neutrophilic inflammation w/ parakeratosis, erosion, ulceration, +/- yeast)
Malassezia dermatitis is found where? How does it infect animals?Can be isolated from the normal skin & external ear canal. The yeast proliferates & causes clinical dermatitis when the microclimate or host defenses are altered
What are the Gross lesions caused by Malassezia pachydermatis?Erythematous, scaly, lichenified & alopecic dermatitis (interdigital, otic, perianal, or intertriginous are most common). (Histologic lesions: Acanthosis w/ parakeratosis, spongiosis, lymphocytic exocytosis, +/- yeast)
How does SQ mycoses occur? What does it lead to?Caused by *traumatic implantation of fungi from the environment. Leads to nodular granulomatous to pyogranulomatous panniculitis & dermatitis
(Subcutaneous mycoses) Eumycotic Mycetoma → How common? Who? Describe the fungiRare infxn of horses & dogs, it is due to a saprophytic fungi (Curvularia geniculata, others) w/ dark-walled, septate hyphae
(Subcutaneous mycoses) Dermatophytic Pseudomycetoma (“deep dermatophytosis”) → Who does this affect? What might be the reason for this? What is it caused by?Rare infxn ONLY in Persian cats. Suggests a breed-specific genetic deficit. Microsporum canis (Persian cat is apparently a pseudo fungi dog)
(Subcutaneous mycoses) Phaeohyphomycosis → Caused by?Pigmented fungi (Alternaria sp., others) (Dark phae)
(Subcutaneous mycoses) Sporotrichosis → How common? Who? Any notes about this?Uncommon infxn of humans, horses, mule, cattle, cats & dogs. Can be ZOONOTIC esp from infected cats.
(Subcutaneous mycoses) Sporotrichosis → CAUSATIVE AGENT? Describe itCaused by saprophytic, dimorphic fungi, Sporothrix schenckii. Intrahistiocytic yeast are 4-10 um, ovoid to elongate, cigar-shaped bodies surrounded by clear halo
Zoonotic Subcutaneous mycoses?Sporotrichosis
*(Subcutaneous mycoses) Oomycosis → Which organism is an oomycosis which causes subcutaneous mycoses?Pythiosis
(Subcutaneous mycoses) Pythiosis aka? Causative agent? Happens in who? Where is this most common (geographically)Aka "swamp cancer" which is caused by Pythium insidiosum. Occurs in horses, cattle, dogs & cats. Most common in southern Gulf States (insidious pythons)
(Subcutaneous mycoses) Pythiosis what are the gross lesions? Where do they usually occur?Necrotizing subcutaneous nodules that ulcerate & drain & are usually located on the distal limbs & ventrum
(Subcutaneous mycoses) Zygomycosis is caused by what? How does this infxn occur?Opportunistic infxns caused by saprophytic Zygomycete fungi
Systemic mycoses causing cutaneous lesions → How does this occur? What are the gross lesions?Cutaneous lesions may occur by systemic spread to the skin, or by direct implantation of fungi by traumatic injury. Gross lesions: Nodular skin which may have draining tract
What are 4 organisms which are Systemic mycoses causing cutaneous lesions?Blastomyces dermatitidis, Coccidioides immitis, Cryptococcus neoformans, Histoplasma capsulatum
(Algal infxns → Rare, prolly wont ask us) Protothecosis causes what?Pyogranulomatous dermatitis & panniculitis. (Other algal infxn is Chlorellosis)
Mites → Demodicosis. Usually affects who? What are the gross lesions? What are the histological lesions?Usually affects dogs, esp. juvenile ones. (Can be localized or generalized). Gross lesions: scaly, erythematous, thickened, alopecic areas. Histologic lesion: Lymphocytic Mural Folliculitis w/ intrafollicular mites & occasional sites of furunculosis +/- 2° bacterial infxn
Mites → Scabies. Caused by what? Important notes about scabies? Commonly affects which animals?Caused by Sarcoptes scabiei & important to note that it's highly contagious & zoonotic! (not really true but we can go with this for now) Commonly affects dogs & foxes (sarcoptic mange)
What is the most important ectoparasite of pigs?Scabies (oooohhh yeahhhh)
What are the gross lesions of scabies & why is this?Gross lesions: scaly, erythematous, thickened, alopecic areas Mites burrow in tunnels in the stratum corneum & cause intense pruritus w/ marked acanthosis & hyperkeratosis!
Notoedric mites → Name of mite? Happens in who? Things to know?Notoedres cati infestation occurs in cats & rabbits, less commonly in foxes, dogs & humans. Highly contagious & pruritic
Otodectic mites → Name of mite? Happens where in who?Otodectes cynotis occurs in the external ear canal of dogs & cats
Psoroptic mites → Happens in who? Specific mites for specific species are?Infestation occurs in horses, cattle, sheep, goats, rabbits & others. Psoroptes cuniculi is common in the ear canal of rabbits. Psoroptes ovis is cause of sheep scab
Chorioptic mange → Name of mite? Affects who?Chorioptes bovis affects horses, cattle, goats, sheep
Cheyletiellosis → Caused by what sp of mite? Affects who, what w/ results? (Where does the mite live?)Cheyletiella sp. infests dogs, cats, rabbits, wild animals & humans. The mite lives on the surface of the skin & induces hyperkeratosis & detritus (dandruff) along the dorsal midline
Psorergatic Mites → Which sp affects which animal specifically? (Where geographically)?Psorergates ovis infestation occurs in sheep in Australia, New Zealand, South Africa & Argentina (PSORE sheep in Australia)
Trombiculiasis → Aka? What’s happening?Trombiculiasis is infestation by larvae of trombiculid (harvest) mites also known as chiggers. (Chiggers playing trombones)
Cutaneous rxns to tick bites result in? What might make this worse?Focal dermatitis resulting in papules & circular areas of erythema. Tick-bite lesions may become 2ndarily infected by bacteria leading to more severe dermatitis
Heavy tick infestations might lead to what?Anemia & weakness
Explain "tick paralysis"Tick paralysis is a rare condition of acute lower motor neuron paralysis caused by neurotoxins in tick saliva.
Blood borne dzs & agents vectored by ticks? (5)Rocky Mountain spotted fever (Rickettsia rickettsia)
Lyme dz (Borrelia burgdorferi)
Anaplasmosis (Anaplasma marginale)
African Swine Fever (Asfaivirus)
Hemotropic mycoplasmas
Mallophaga are?Biting lice (I bit MALLory)
Anoplura are?Blood-sucking lice (plural blood cells being sucked)
What is Pediculosis? What might this lead to?It is an infestation of lice. May lead to skin irritation & pruritus w/ papules, crusts, excoriations & traumatic hair loss
Haematopinus suis is a what? Why do we care? What might this result in?LICE INFXN. Economically important. Can lead to hypersensitivity dermatitis, but more importantly, is a VECTOR for swine pox, African Swine Fever & Eperythrozoon suis
What are some reasons fleas can cause severe skin irritation? What other problem might they cause?Frequent biting → Intense pruritus causing self-inflicted trauma. There are also Flea bite hypersensitivity rxns to flea saliva. Might also cause severe anemia, esp. in puppies & kittens
What is the gross lesion caused by fleas/flea bite hypersensitivity rxns (couldn't tell which he was referring to)? Who do fleas usually affect? What can fleas be a vector for?Gross lesion: Miliary dermatitis. Usually a problem for cats & dogs. Vector for tapeworms (Dipylidium caninum)
Flies → Which fly causes an insect bite hypersensitivity in horses & what is it commonly called?Culicoides sp. “sweet itch”
Cutaneous myiasis is aka?Fly strike
Culicoides sp, aside from causing sweet itch in horses, cause what other problems?Transmission of orbiviruses can lead to cutaneous hemorrhage & edema (blue tongue, Epizootic hemorrhagic dz, African horse sickness)
Cutaneous Habronemiasis (Summer sores) of the horse is caused by what? How is it transmitted? What are the gross lesions?(HELMINTHS) Caused by Habronema sp. or Draschia sp. Transmitted by house flies or stable flies & incidence coincides w/ fly season. Gross lesions: Nodular ulcerated areas commonly on legs, prepuce, face & medial canthus of eye
Hookworm dermatitis is caused by what? What are the gross lesions & histopath?HELMINTHS. Caused by cutaneous migration of Ancylostoma sp. or Uncinaria sp. Gross lesions: Erythematous papules & linear to irregular areas of lichenified alopecia commonly on the feet of dogs. Histologic lesions: Larval migration tracks w/ eosinophilic dermatitis
Onchocerciasis of horses (caused by what type of organism?) how does transmission take place? What are the lesions?HELMINTHS → Onchocerca sp. Biting flies transmit the microfilariae. Lesions: causes granulomatous nodules on ventral midline, head, neck & medial forelimbs
Stephanofilariasis is caused by? Affects who? What are the lesions it causes?HELMINTHS → Stephanofilaria sp. biting flies transmit microfilaria to cattle, buffalo & goats. Lesions: causes granulomatous nodules on ventral midline
Cutaneous Leishmaniasis is caused by what kind of organism? Affects who?It is a PROTOZOA. Dogs, cats & rodents serve as reservoirs of infxn for humans. Leishmania Infantum infxn is endemic in Foxhounds throughout the US.
What are the gross lesions seen in Leishmaniasis? WHERE are they usually seen? (Histologic lesions?)Gross cutaneous lesions in dogs & cats consist of alopecia, nodules & ulcers which Most often occur in areas which sandflies feed & transmit the organisms (muzzle, nose, ears & eyes). (Histologic lesions: Nodular granulomatous & ulcerative dermatitis w/ Intrahistiocytic Amastigotes)
Other protozoa which OCCASIONALLY cause cutaneous lesions (aside from Leishmania) are?Toxoplasmosis, Neosporosis, Sarcocystosis, Caryosporosi

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