SAD Ch 18 Miscellaneous Skin Disease Flashcards
What leads to the development of cicatricial alopecia?
Cicatricial alopecia results from insults to the skin that cause fibrous tissue deposition that replaces follicular units and adnexal structures.
What are the most common causes of cicatricial alopecia?
Localized injection reactions, ischemic dermatopathy, vasculitis, dermatomyositis, sterile nodular panniculitis, posttraumatic scarring, erythema ab igne, and thermal burns.
True or false: alopecia seen in cicatricial alopecia is permanent
True
What are the histopathologic features of cicatricial alopecia?
Fibrosing dermatitis with lack of hair follicles or adnexal glands that connect to the overlying epidermis. The overlying epidermis is often acanthotic but may be ulcerated or unremarkable
What is the treatment for cicatricial alopecia?
Surgical removal of the affected area, otherwise the area will remain alopecic.
What is the cause and pathogenesis of granulomatous sebaceous adenitis?
Idiopathic It is believed that sebaceous gland destruction is due to a cell mediated immunologic reaction directed against a component of the sebaceous gland
What breeds are predisposed to sebaceous adenitis
Standard poodles, viszlas, akita’s, German Shepherd dogs, and samoyeds. Also Springer spaniel’s and Lhasa apsos
What variation and clinical presentation is commonly seen with Akitas and Springer spaniel’s with sebaceous adenitis?
More pyoderma and severe disease
What are follicular casts?
When a hair or group of hairs develop a sheath of keratin debris that remains attached to the hair above the follicular ostia
True or false: pruritus is not typically present with sebaceous adenitis unless a secondary infection is present
False. Pruritus varies from not present to intense and as such is not a helpful diagnostic finding
True or false: dogs and cats rarely undergo spontaneous remission of sebaceous adenitis
True
What is the only treatment to date shown to result in an increase in sebaceous glands along with clinical improvement in sebaceous adenitis?
Cyclosporine
What condition has been characterized by chronic idiopathic hypereosinophilia associated with a diffuse infiltration of various organs by mature eosinophils?
Hypereosinophilic syndrome
It has been recommended that peripheral blood eosinophil counts exceeding _____ be considered hypereosinophilia in dogs and cats.
5x10^9/L
What signalment of cat is more likely to be affected by hypereosinophilic syndrome?
Middle-aged females
Which organs are typically involved in hypereosinophilic syndrome?
Bone marrow, lymph nodes, liver, spleen, GI tract. Rarely cardiac.
What dermatologic signs are seen in cats with hypereosinophilic syndrome?
Generalized maculopapular erythema, severe pruritus, marked excoriation, and possibly wheals and soft-tissue swellings of the limbs.
How is hypereosinophilic syndrome diagnosed?
Combination of unexplained prolonged eosinophilia and evidence of multi organ involvement.
What is the prognosis for hypereosinophilic syndrome?
Poor. Survival times are short and patients do not respond to treatment.
What condition is characterized by progressively enlarging skin folds, especially over the neck and trunk?
Idiopathic diffuse lipomatosis
What are the histopathologic findings in idiopathic diffuse lipomatosis?
Diffuse thickening of the panniculus. Proliferating fat may resemble mature adipose tissues with mucinosis only of interlobular septae and with small numbers of primitive mesenchymal cells and lipoblasts around blood vessels. In other cases, the normal anatomy of the panniculus is lost in a proliferative mixture of normal appearing and dysplastic lipocytes.
What is the treatment for idiopathic diffuse lipomatosis?
No effective therapy.
At what age are animals with idiopathic greasy skin and haircoat with sebaceous gland hyperplasia diagnosed?
Usually within the first year of life
What are the histopathologic findings of idiopathic greasy skin and haircoat with sebaceous gland hyperplasia?
Remarkable sebaceous gland hyperplasia. Otherwise, the skin appeared normal.
What’s wrong with this dog?
Lichenoid dermatitis
What is the cause of lichenoid dermatosis?
Unclear, but immune-mediate pathomechanism is suggested.
Describe the lesions present in lichenoid dermatoses.
Asymptomatic symmetric onset of grouped, angular, flat-topped papules, which develop a scaly to markedly hyperkeratotic surface.
What are the differentials for lichenoid dermatoses?
Psoriasiform lichenoid dermatosis of English Springer spaniels, actinic keratosis, some papilloma viral lesions, and cyclosporine induced lichenoid plaques.
What are the histopathologic findings in lichenoid dermatoses?
Hyperkeratotic and hyperplastic lichenoid and hydropic interface dermatitis
Usually lymphoplasmacytic inflammatory infiltrate
In lichenoid dermatoses, what histopathologic findings might influence your treatment plan?
If intraepidermal pustular dermatitis, suppurative folliculitis or both are present, suspect a lichenoid tissue reaction in response to staphylococcal infection. Should respond to antibiotics.
If eosinophilic microabscesses are present, suspect a lichenoid tissue reaction in response to an ectoparasite (especially scabies or cheyletiellosis) or Malassezia
What is the prognosis for idiopathic lichenoid dermatoses?
Good. All cases have undergone spontaneous remission after a course of six months to two years.
What form of therapy has consistently been shown to be beneficial in the treatment of idiopathic lichenoid dermatoses?
Sorry, trick question. No form of therapy has consistently been shown to be beneficial.
What are some ideologic factors involved in the genesis of panniculitis in dogs and cats?
(hint, there’s a lot)
Which two species of bacteria appear to target the panniculus?
Mycobacterium and Nocardia
Panniculitis has been associated with disease of which internal organ?
Pancreas
Which hereditary disease predisposes humans to sterile panniculitis?
Hereditary deficiency of α1-antitrypsin
True or false: association with anti-trypsin levels has been detected in dogs with sterile nodular panniculitis.
False. It has not been detected
Which breed has been reported to be predisposed to sterile nodular panniculitis?
Dachshunds (51% in one study)
Possibly also miniature poodles and collies.
What other clinical signs can be seen with panniculitis, especially in dogs with multiple lesions?
Pyrexia, poor appetite, depression, lethargy, arthralgia, abdominal pain, vomiting, hepatosplenomegaly.
Fat necrosis in other organs including bone, spinal canal, and abdomen have also been reported.
Do dogs with sterile nodular panniculitis more commonly present with a solitary lesion or multiple lesions?
What about cats?
Dogs-debatable, one study showed more often it was single one study showed more often it was multiple.
Cats-solitary lesion in the majority(95%). Most commonly over the ventral abdomen and ventrolateral thorax
What might you see on an aspirate from a nodule in sterile nodular panniculitis?
May be suppurative, pyogranulomatous, or granulomatous with lipid or fat cells present.
Macrophages may be particularly foamy, but no microorganisms are seen
Occasionally the presence of spindle cells leads to an erroneous cytologic diagnosis of neoplasia.
Describe the histopathologic findings of panniculitis.
Usually lobular or diffuse but in some cases maybe septal.
The infiltrate maybe granulomatous, pyogranulomatous, suppurative, eosinophilic, necrotizing, or fibrosing.
The presence of saponification and necrotic fat is associated with pancreatic disease-induced sterile nodular panniculitis and also vitamin E pansteatitis in cats.
What is considered the minimum database to search for concurrent disease before a definitive diagnosis of sterile nodular panniculitis can be reached?
Abdominal ultrasound in chemistry screens with amylase and lipase (E. G., pancreatic lipase immunoreactivity)
CBC may show mild to moderate leukocytosis and neutrophilia, and a mild non-regenerative anemia in animals with multiple lesions And systemic illness.
What is the treatment for sterile nodular panniculitis?
In one case, when pancreatitis was resolved, the panniculitis also resolved.
Careful surgical excision of solitary lesions maybe curative.
Multiple lesions usually respond well to systemic glucocorticoids. (2 mg/kg once daily in dogs, 4mg/kg once daily in cats). If no cause is found or the underlying disease is effectively treated, attempts to stop therapy after remission are warranted. Recurrent cases can be treated with alternate day steroid therapy.
Azathioprine or cyclosporine can also be used.
Oral vitamin E 400IU q12 has shown good results. Tetracycline and niacinamide have been reported effective.
What is split paw pad disease?
Unknown etiology. Thought to be associated with a congenital defect in cornification of the foot pads. The defect weakens the epithelium and results in separation of the superficial layers from the deeper layers of the epidermis when friction is applied to the pad.
Wet feet are at greater risk
What are the characteristic histopathologic findings for split paw pad disease?
Brightly eosinophilic, coagulated appearance that extends into the superficial dermis and resembles the severe coagulation no necrosis of a burn.