Dermatology Flashcards
Describe the epidermis.
The outer epidermis is a tough waterproof barrier. basal epidermal cells continually divide, migrate outwards and are shed from the surface. The thickness varies with breed and anatomical site. It is usually 3-4 cells deep in haired skin in dogs and cats but thicker over the nose and footpads. The skin is thicker in farm species and horses. The basal epidermis also contains melanocytes that are important in pigmentation and langerhans cells that are important in immunity and inflammation. There are no blood vessels in the epidermis.
What are the functions of the skin?
Tough outer barrier, immune system protects against infection, protection against UV radiation, temperature regulation, sensations of touch, pressure, itch pain and heat, produces vitamin D.
What are the different layers of the epidermis?
Stratum corneum - tough waterproof barrier formed by keratinised squames and intercellular sebum.
Granular layer - keratin granules form and nuclei are lost
Spinous layer - cells begin to migrate
Basal layer - actively dividing cells
Basement membrane - adheres the basal layer to the dermis.
Describe the dermis
A network of collagen and elastin fibres in a gel like proteoglycan matrix that makes the skin tough, flexible and elastic. The dermis also contains blood vessels, lymphatics and nerves to the skin. Fibroblasts, mast cells, dendritic cells and other cells important in inflammation and repair. It also has hair follicles and associated structures.
Describe hair follicles found in cats and dogs
hair follicles are found everywhere except the nose and footpads. They are denser along the back and sparsar on the underside of the boyd. hairs are produced by division of epidermal cells at the base of the follicle. An invagination of the dermis - the dermal papilla - rich in blood vessels and hormone receptors governs hair growht. Hair growth follows: exogen (Active expulsion of the hair), anagen (growth), catagen (involution) and telogen (resting). Most animals moult and grow a new coat. Exceptions to this are breeds with anagen type coats such as poodles etc that dont shed hair but need haircuts.
how is hair growth controlled?
Multiple influences including genotype, photoperiod and temperature, thyroid, adrenocortico and sex steroid hormones and nutrition. Basic type of coat has coarse primary guard hairs and a dense undercoat of fine secondary hairs. This is also known as a double coat. Short and long single coats have a more uniform collection of hairs. The hairs can be straight (smooth) or curly (wooly or wire haired). dogs and cats tend to have compound follicles whereas other species have simple folicles. The hair follicles lie at an angle within the skin allowing the coat to lie naturally from head to tail. Arrector pili muscles can pull them upright, raising the hairs for insulation and social signals. Whiskers are specialised touch sensitive hairs, longer and thicker than ordinary hairs, found on the muzzle and face. Smaller whisker like hairs also sensitive to touch are scattered throuughout the coat.
Describe different coat and skin colours
There are two t ypes of melanins - blackbrown and yellow red. The final colour depends on the distbution of micromelanosomes in the keratinocytes and hairs. Agouti hairs have a brown base gradually darkening towards the tip. Other coats are a single colouur, have piebald distribution or lack pigment 9white). Blue and fawn coats are dilutions of black and red, caused by clumping of melanin granules into macromelanosomes. These are associated with colour dilution alopecia in some breeds. Many colours do not breed true.
Describe sebum and sweat
Sebum is secreted by sebaceous glands that secreete into hair follicles. Sebum provides nutrients, antibodiies, protects against infection and prevents drying. Atrichial sweat glands secret onto the skin surface, on the nose and footpads, and epitrichhial glands secrete into hair follicles. Sweat is used to thermoregulate in humans, cattle and horses but not in dogs and cats.
Where is the specialised skin of the body found
the nose and footpads are different from the rest of the skin, it is hairless, very thick and tightly attached to underlying tissues making these sites very tough ad resilient. Claws and hooves are also tightly adherent to underlying tissues. The specialised epidermis of the corium or nailbed produces a thick and highly keratinised stratum corneum with a low lipid content, making it very strong and rigid.
Describe how age/breed may affect your ddx for skin cases
75% of allergic diseases start between 6 months and 3 years old. very young: congenital problems and parasites.
Young adult: immune mediated and follicular dysplasias.
Elderly: neoplastic and metabolic.
Many conditions have a breed/sex predisposition.
Describe how onset and duration may affect your ddx for skin cases.
Insidious: hypersensitivity, metabolic, endocrine, neoplasia
Acute: parasite, infectious, immune mediated
WAxing and waning: hypersensitivity, immune mediated
Progressive: metabolic, endocrine, neoplastic
Intermittent: parasites, infections.
Seasonality: allergies and some parasites.
How is clinical exam of the skin done?
Skin easily examined - carefully observe and evaluate skin lesions and other findings e.g fleas, lice trombicula. you should be able to recognise and understand common skin lesions type and distribution. The common causes of skin disease: dogs- parasitic, infections - staphylococcal, malassezia, dermatophytes, allergic, endocrine, neoplastic.
What are the common parasitic causes of pruritis?
Flea infestation, otodectes cyanotis, cheyletiella species, neotrombicula autumnalis, sarcoptees scabiei, demodex, lice, notoedres, endoparasites
What are the most common types of hypersensitivty reaction which cause pruritis?
Flea allergic dermatitis, atopic dermatitis, adverse food reactions, allergic or contact dermatitis.
What are the most common infectious causes of pruritis?
Bacteria/malassezia, cowpox, feline herpesvirus, dermatophytosis, FIV and FeLV.
What are fleas?
Small red brown laterally compressed and fast moving insects. most commonly infest the tailhead, rump, dorsum, ventral abdomen and flanks but cats may show clinical signs elsewhere. They cause mild irritation to severe pruritis and inflammation; anaemia is possible in young animals. they are the vector for dipylidium caninum and cat scratch fever. Fleas will affect dogs, cats, rabbits ferrets and humans.
How can fleas be controlled?
For immediate control treat all inc ontact animals with an efefctive on animal adulticide and the environment with a combined larvidcide/insect growth regulator. Vacuuming will stimulate the pupae to hatch and improve the efficacy of environmental treatment. Monthly on animal treatment is enough for long term control in most cases but some animals will benefit from concurrent long term environmental treatment. IGRs are very safe but only break the life cycle and prevent environmental build up - adult fleas can stil be acquired. Wide range of flea control products available with combined insecticidal, acaricidal, anti tick and anti endoparasite actibity. They come in a variety of forms including oral, sprays, spot ons and collars. Neer use permethrin in homes with cats.
What are the clinical signs of sarcoptes scabiei and notedres cati?
papules, scaling, crusting, excoriation and alopecia. on the ears, face, elbows, hocks and ventral chest in sarcoptes scabiei and in notedres cati - head and neck.
What are the clinical signs of cheyletiella in cats and dogs?
Variable pruritis and scaling - walking dandruff, truncal
What are the clinical signs of otodectes cyanotis in dogs and cats?
Otitis, dark brown waxy discharge, zoonotic, on ears head cranial body
What is the treatment for mites and lice?
Treat all in contact animals with an effective acaricide for 4-6 weeks to kill newly hatched larvae. Adults can live in the environment for short periods - clean bedding equipment etc. Environmental treatment may be necessary.
describe non contagious parasites that may cause pruritis?
Neotrombicula adults live in thick vegetation. the larvae infest animals in the late summer and autumn. the bright orange mites can be seen in the ear, axillae, ventral body, interdigital skin and tail. Vulerable to most acaricides but animals will be re infested from environment. A long acting product such as fipronil spray applied to feet and ventral body every 7-14 days can be effective. Demodicosis is usually associated with erythema, papules, alopecia, scaling and comedones. Free living pelodera nemotodes or hookworm larvae can occasionally cause severe dermatitis of the feet and ventral body in kenneled dogs where hygiene is poor.
Describe malassezia in dogs
Malassezia are part of normal flora, in the ears, feet and mucocutaneous junctions and infections are usually secondary to an underlying cause. In dogs malassezia otitis and dermatitis are common. (odour erythema, hyperpigmentation, lichenification, seborrhoea and alopecia) its less comomn in cats but can be associated with otitis externa, paronychia, felie acne, facial dermatitis and underlying systemic diseases. Treatment with chlorhexidine/micoonazole shampoo and topical clotrimazole/miconazole and nystatin containing products is usually effective but some cases may need systemic treatment with itraconazole.
Describe the most common hypersensitivity diseases which may cause pruritis
Allergic skin diseases are complex familial conditions that involve abnormalities in skin barrier function and skin inflammation in addition to an alergy. Animals can exhibit multiple overlapping patterns. Most cases of atopic dermatitis are associated with allergies to environmental allergens such as house dust mites, epidermals, insects, pollens and moulds. boxers, labradors, gsds, whwts and other terriers predisposed. Animals with pollen allergies may have seasonal clinical signs but most start or eventually become perennial. OTher fare flactors include stress or anxiety, change in temperature and humidity, ectoparasites and infections.
What are the clinical signs of atopic dermatitis and adverse food reactions?
pruritis, no skin lesions, mild to moderate erythema, saliva stains, muzzle ventral pinnaae neck axillae abdomen groin perineum and feet. Chronic inflamation with hair loss, excoriatioin, papules, scaling and crusting, hyperpigmentation and lichenifiation. Skin may be dry, moist or greasy. Chronic or recurrent otitis externa, occasionally unilateral with or without other skin lesions. Recurrent staphylococcal pyoderma and malassezia dermatitis.
How are alergic skin dieases diagnosed?
By eliminating other causes of pruritis, controlling infection and determining the pattern of allergies for each patient. A 6-8 week food trial with a home cooked or commercial nvoel single protein diet and water only should be used to see whether food is a trigger for the pruritis. hydrolysed diets may help in cases where it is difficult to fiind novel ingredients but these are expensive and some animals may still react to the ingredients. Clear written instructions, follow up and good communication are important in maintaing compliance. They wax and wane so relapse after challenge with the usual diet is necessary to confirm diagnosis.
What is allergy testing?
Can be used to identify environmental allergens for avoidance or allergic specific immunotherapy. Most dermatologists prefer intradermal allergen tests as these directly test the capacity of the skin to react to the allergens. Most first opiinion practices use serology tests although there are some concerns over the reliability of these. allergy tests must not be used to confirm the diagnosis of atopic dermatitis - positive tests can be seen in healthy animals or other pruritic skin diseases.
What is allergic and irritant contact dermatitis?
Only affect skin in direct contact - usually sparsely haired ventral skin, the feet or the site of application of topical medication. REactions can be seen to topical drugs, cleaning fluids, plastics or metal bowls, carpet dyes, concrete etc. It usually resolves within a week of removing the suspect substances. Patch tests with suspect substances applied to the skin can confirm the diagnosis but these are difficult to perform.
What is acral lick dermatitis?
Caused by chronic self trauma to the cranial and lateral aspects of the distal limbs and other sites. Most involve a long standing deep bacterial folliculitis, lichenification and scarring. these are numerous potential cases including behavioural problems, musculoskeletal problems, neurlogical disorders and other pruritic skin diseases. Take good history. Long term control may require behavioral therapy and mood modifying drugs. It is important to note that stress and anxiety can worsen allergic skin disease.
What is epitheliotropic cutaneous T cell lymphoma?
Usually seen in older dogs and rarely cats. the clinical signs can be very varied with diffuse or localised erythema and scaling, plaques, ulcers or nodules an variable, often severe pruritis.
What is demodex?
Demdex mites are commensal, although the short bodies D gatio can be contagious in cats. Dogs and cats have at least three species of mites with different morphology that are found in hair follicles associated with sebaceous glands and on the skin surface. Localised juvenile onset demodicosis occurs during adolescence and presents with multifocal alopecia, scaling, comedones and follicular casts. It isnt pruritic unless there is secndary infection. Generalised demodicosis is more severe alopecia, scaling, hyperpigmentation, comedones and follicular casts. Clinical signs may b e limited to feet. Secondary bacterial infection common. May be peripheral lymphadenopathy with pyrexia. Juvenile form often resolves with maturity. Generalised form is more serious, probably wont resolve and requires treatment. True adult onset demodicosis usually secondary to underlying disease.
What is the treatment of demodex?
Amitraz (aludex) dip once weekly. Wash with keratolytic and degreasing shampoo to remove debris and clip longhaired animals. Adverse effects include vomiting, sedation, bradycardia, pruritis, exfoliative erythroderma and hyperglycaemia. It is toxic to chihuahuas and cats and can cause side efects in humans. Lime sulphur dip used in mild cases. Imidacloprid spot once weekly in milder cases. Ivermectin or moxidectin. not licensed. Milbemycin oxime once daily effective and well tolerated even in MDR positive dogs. Should be treated until 2-3 skins crapes negative at 7-14 days intervals.
what is dermatophytosis?
Dermatophytes are fungi that metabolise keratinised tissues. Common species include microsporum canis, microsporum gypseum and trichophyton mentagrophytes. Dermatophytosis is usually associated with multifocal alopecia and scaling. Less common problems include paronychia and kerions, miliary dermatitis and fungal granulomas in persian cats. Trichophyton species in rodents and rabbits are more inflammatory causing alopecia, erythema scaling crusting and secondary infection. Persian cats and Yorkshire terriers are predisposed. Most cases seen in young animals but cases also occur secondary to underlying immunosuppresive diseases. Highly contagious and zoonotic.
What is the treatment of dermatophytosis?
localised dermatophytosis in young animals usually spontaneously resolves but all cases should be treated to reduce contamination of environment, contagion and zoonosis. Clipping long haired animals may help, but can also worsen clinical signs. Itraconazole licensed in cats, well tolerated, should be treated until they have had at least two consecutive negative cultures at least 7 days apart. Topical treatment can be used on very local lesions, but usually use d to decrease time to clinical cure and decrease environmental contamination. Suitable products include chlorhexidine/miconazole malaseb shampoo or enilconazole dip. Environmental decontamination very important especially in multicat households and shelters. This includes thorough cleaning and vaccuming, careful disposal of contaminated items and use of antifungal agents.
What is leishmania?
Should be suspected in animals that have travelled to endemic areas. Owners should use anti sandfly products in endemic areas e..g delttamethrin colalrs. Cutaneous - focal alopecia with fine silvery white scaling, depigmentation, nodules, ulcers and crusting of the face nose pinnae and feet. Systemic - lymphadenopathy,hepatomegaly, splenomegaly, anaemia, ocular signs, kidney failure, lameness, muscle atrophy and pyrexia. Serology PCR and identifying the organism in biopsies from affected skin used as diagnosis. treatment options include meglumine antimoniate, allopurinol and miltefosine but a complete cure is difficult.
How many immune mediated diseases cause alopecia?
Clinical signs of dermatomyositis and vasculitis include alopecia, erythema, crusting and scaling f the extremities, periocular skin and bony rominences, although mild vasculitis may present with alopecia only. Dermatopmyositis may show muscle atrophy, weakness, stiff gait and facial palsy. Inflammation usually not apparent in alopecia areata which can be restricted to pigmented hairs. lymphocytic mural folliculitis is uncommon that causes variable patterns of alpecia and erythema.
How many endocrinopathies cause alopecia?
Perturbations in hormone lvels at the follicular level tend to have similar effects so endocrine dermatology have similar clinical effects. common features include; symmetrical non inflammatory alopecia, dull dry faded coat that is easily epilated, coat fails to regrow after clipping, mild to moderate scaling, easily bruised skin and poor wound healing, increased susceptibility to infections.
How is hyperadrenocorticism characterised?
Bilaterally symmetrical truncal hair loss, comedones, atrophic and inelastic skin, prominent blood vessels and calcinosis cutis, fragile skin and tearing is more common in cats.
How does hypothyroidism affect the skin?
Can be very variable with any combination of systemic and cutaneous signs. Truncal alopecia with thickened hyperpigmented and cool skin is classical but most dogs show partial alopecia with a faded coat. In others it may be restricted to the tail and dorsal nose.
How do sex hormone alterations cause alopecia?
They tend to initially affect the caudal ventrum and genitalia spreading to the limbs, flanks and neck. hyperoestrogenism is asssociated with gynectomastia, vulval swelling and signs of oestrus. Sertoli cell tumours are most common ni cryptorchid testes and cause attraction to male dogs, gynectomastia, pendulous prepuce and linear preputial erythema. Hyperandrogenism associated with neoplasia or functional abnormalities in older dogs causes caudal and perianal gland hyperplasia and patchy anogenital hyperpigmentation.
What is telogen effluvium and anagen defluxion?
Associated with synchronous hair cycle arrest and subsequent hair loss. In telogen effluvium events such as pregnancy lactation systemic illness etc cause the hairs to enter telogen. Alopecia arises some time later when the resting hairs are pushed out by new anagen growth or removed by grooming. anagen defluxation is similar but caused by more severe insults that interupt anagen. the weakened hair shaft is easily fractured causing apparent hair loss. causes include systemic illness, bacteriaemia, malignancies, chemotherapy and drug reactions. uncommon but may be seen in anagen breeds such as poodles.
What is feline paraneoplastic alopecia
usually associated with pancreatic and bile duct carcinomas. Cutaneous signs are highly specific and usually noted before systemic illness. Ventral truncal alopecia with strikingly smooth, shining thin and translucent skin. If diagnosed early the clinical signs are reversible with surgical exciision of the tumour - although metastasis are common and prognosis generally poor.
Describe congenital alopecias?
Rare sporadic problem in many breeds although considered normal in hairless breeds. The clinical sign depend on the genetic abnormality whiich may be dominant recessive or sex linked. the adnexae, skin claws and teeth may also be affected.
What is pattern baldness?
these syndromes are caused by follicle miniaturisation resulting in focal alopecia. the skin may be hyper pigmented but is otherwise normal. pattern baldness seen in Yorkshire terriers, daschunds and greyhounds.
What are follicular dysplasias?
Inherited diseases causing abnormal growth and development of the hair follicles in irish water spaniels, water dogs and other breeds. the puppy coat is initially normal but becomes dull brittle and is lost predominantly from the trunk and wear oints. There is often scaling and secondary infection, which can be pruritic. hair regrowth is irregular and abnormal. Black hair follicle dysplasias affect black areas in black and white dogs. Colour dilute alopecia affects dilute colour coats such as blue or fawn dobermans.
What are the treatments for congenital and hereditary alopecias?
Avoid further damage to coat, gentle anti scaling and moisturising shamppos, control secondary infections, high quality diets and essential fatty acids, sun protection, melatonin, vitamin A or retinoids.
What is sebaceous adenitis?
A comon problem in standard poodles, vizlas, akitas, samoyeds and ocasionally other breds - associated with inflammation and destruction of sebaceous glands. CLinical signs include dry skin, tightly adherent frond like scales, hair loss and secondary infections. Treatment: anti scaling shampoos, vitamin A or retinoids, high quality diet and fatty acids, ciclosporin, antibiotics and anti bacterial shampoos to counter secondary infections
What is seasonal or cyclical flank alopecia?
Seasonal hair loss on back and flanks in dogs - underlying skin is darker but normal. hair loss and regrowth can vary from year to year. possibly linked to changes in day length. some dogs respond to melatonin.
What is alopecia X?
Chows, pomeranians, keeshonds, poodles and other breeds suffer an unusual pattern of hair loss, which starts in adolescence or young adulthood with loss of primary hairs leaving a wooly puppy like coat, eventually there is a complete alopecia and hyperpigmentation sparing head and limbs. some dogs have abnormal adrenal sex hormone production and respond to trilostane. other treatments include general skin and coat care, melatonin, neutering, deslorelin or sex hormones. regrowth and relapse, regrowth at biopsy, skin scrape sites also seen.
What is the diagnostic approach to focal or multifocal alopecia?
Cytology to rule out stpahyloccal pyoderma. deep skin scrapes, hair pluck, tape strips or impression smears to rule out demodex. dermatophytosis - dermatophyte endospores and hyphae can be visible on microscopy of affected hair shafts. Dermatophytes produce a red colour change that coincides with early fungal growht on dermatophyte test mediium. skin biopsy.
What is the diagnostic approach to symmetrical and diffuse alopecia?
Routine haematology, biochemistry and urinalysis are indicated in symmetrical and diffuse alopecia or where previous skin biopsies are comatible with endocrine alopecia. These do not confirm a diagnosis and further tests reqiuired to confirm diagnosis.
Hyperadrenocorticism - acth stimulation test, low dose dexamethasone suppression test, urinary cortisol:creatinine ratio.
Hypothyroidism - total t4, free t4, TSH.
Serrtoli cell tumour, hyperoestrogenism, praneoplastic alopecia - abdominal imaging.
Alopecia X - sex hormones pre and post ACTH.
What are the common presentations in cats with allergic and parasitic skin deases?
Self induced alopecia, head and neck pruritis, eosinophilic skin diseases - miliary dermatitis, eosinophilic plaque, eosinophilic granuloma, indolent ulcer.
What is miliary dermatitis?
An erythematous papular and crusting dermatitis, commonly seen over the dorsal body, flanks, neck and head. most commonly associated with flea allergic dermatitis.
What are eosinophilic plaques?
Well circumscribed, raised, erythematous and alopecic erosions. They vary in size from small focal lesions to large confluent plaques. They are most common on the ventral abdomen, hind limbs, ventral neck and interdigital skin.
What are eosinophlic granulomas?
Classically seen in young cats with thickened, linear, non ulcerated lesions on the caudal thighs or elsewhere. These are often asymptomatic and can spontaneously regress. These is also an ulcerative and proliferative oral form that may cause halitosis and dysphagia. eosinophilic granulomas have also been associated with firm swelling of the chin. Another form associated with hypersensitivity to mosquito bites causes erythematous erosive and crusting nodules of the nose, pinnae and footpads.
What are indolent ulcers?
erythematous, non healing ulcers of the lips, nasal planum, tongue and hard palate. They are usually small and shallow but can be large and destructive.
What are the Ddx for parasites causing feline pruritis?
Flea allergic dermatitis, otodectes cyanotis, trombicula autumnalis, demodex gatoi, mosquito, sarcoptes scabeiei, notoedres species, cheyletiella, lice.
What are the ddx for infectious causes of pruritis?
Bacterial folliculitis, malassezia, cowpox, feline herpes virus, dermatophytosis.
What are flea control trials?
It is vitally important to eliminate flea allergic dermatitis in cats. all cases should be thoroughly exminaed using a flea comb to look for evidence of fleas and flea faeces. Flea faeces will leave red stains on damp cotton wool. Microscopic examination of skin debris collected using adhesive tape strips can be used to detect tiny fragments of flea faeces. Flea allergen tests are very specific for flea allergic dermatitis but will miss many cases. Pruritis cats also groom away evidence of fleas and trial therapy is therefore necessary in all pruritic cats. aLl in contact animals should be intensively treated over a6-8week period with an on animal adulticide. the environment should be treated with a combined larvicide insect growth regulator. prednisolone can be used for 3-5 days to break the itch scratch cycle.
Describe food trials in cats
Food trials are more difficult to perform in cats. they are selective feeders and tend to like more variety than dogs. they usually wont eat carbohydrate and home cooked trials normally use protens onl. these are deficient in taurine and other nutrients, although this shouldnt cause problems in healthy adult cats over a 6-8 week food trial. outdoor cats will have access to other foods but keeping these cats indoors can increase stress that could exacerbate their skin disease. dogs can be starved if they wont eat the trial food, but this cant be done in cats because of the risk of hepatic lipidosis. many food trials stopped early.
How may psychological triggers affect skin disease?
Purely behavioural or psychological skin disease is uncommon but these triggers can be important exacerbating factors in allergic and other inflammatory skin diseases. potential problems can be seen with oriental breeds, cats with a nervous or shy nature, addition or loss of a human family member, another cat, territorial competition and home environment changes. cats are solitary animals and it is very important to determine how many social units there are in multi cat households - esentially, cats that engage in relaxed physical contact can be regarded as one social unit. there should be at least one feeding station, litter tray and rest point per social unit in different parts of the house.
Describe allergy testing in cats.
Th diagnosis of atopic dermatitis is uncertain in cats, as unlike dogs, suitable clinical and diagnositic criteria have not been established. positive tests may also be seen in healthy cats and cats with other skin diseases and many cats with presumed allergic skin disease have negative tests. nevertheless, allergy testing to identify reactive allergens for avoidance and immunotherapy is warranted in cats with pruritus and or eoosinophilic skin diseases where other potential triggers have been ruled out.
What is exfoliative dermatitis and thymoma?
A rare paraneoplastic syndrome seen in older cats with focal to generalised erythema, exfoliation and malassezia and or pyoderma. systemic clinical signs include anorexia, malaise, coughing and dyspnoea. the thymoma can be demonstrated on thoracic radiography. thoracotomy and excision of the thymoma is curative. similar syndromes with erythema, alopecia,e xudation, scaling, pruritis and malassezia dermatitis can be seen with underlying systemic diseases including hepatopathy, lymphoma, pulmonary tumour, chronic renal failure. Pulmonary tumours can also metastasise to the digits, infiltrating p3 causing lung digit syndrome.
What is feline ulcerative dermatitis?
Associated with well defined ulcerative and crusting lesions over the dorsal neck or shoulders. pruritis is variable. some lesions have been associated with injection site or spot on reactions but not consistent. diagnosis based on the clinical signs and biopsy. the prognosis is guarded as these lesions can be difficult to manage. treatment options include prevention of self trauma using collars or bandages, avoiding injections and spot on treatments, surgical excision, aggressive steroid therapy and ciclosporin.
What is oro facial pain syndrome?
An uncommon problem mostly seen i burmese and related cats. the cats present with violent and frenzied self trauma of the mouth face and neck. the problems seem to arise in the oral cavity and there is a poor response to anti inflammatory agents. it is probably a neurological problem as there is a better response to gabapentin, phenobarbital and benzodiazepines. some cases have associated with herpes virus neuritis and may respond to famciclovir.
What is feline cowpox?
Feline cowpox infections superficially resemble Miliary dermatitis but the papules are fewer in number and larger with a depressed centre that is covered with a small crust. Careful examination will distinguish these from miliary lesions. there should also be a primary bite wound or scratch. affected cats have a 7-10day viraemic phase before the generalised skin lesions develop. Although clinical signs such as malaise and pyrexia may not be evident. some cats especially if treated with steroids develop systemic disease with pulmonary lesions and vasculitis.
what is feline chin acne?
associated with mild to severe furunculosis of the modified sebaceous glands of the chin. Affected cats present with swelling of the chin, seborrhoea, exudates and crusts. the lesions may be paiinful. there is usually a secondary a bacterial infection. There are a variety of potential triggers but this is most commonly associated with behavioural triggers causing hyperplasia of the glands and increased rubbing. treatment involves cleaning the lesions, treating any secondary infection and behavioural modification.
What is facial seborrhea?
Facial seborrhea is almost always seen in persian cats. Affected cats present with thick, black, greasy and tightly adherent scales overlying erosions around the eyes and nose. there may be secondary malassezia infection. severe lesions may be extensive and painful in severely affected cats. the cause is unknown. prognosis is guarded as there is variable response to bathing, anti malassezia treatment, steroids and ciclosporin.
What is fragile skin syndrome?
Fragile skin syndrome is an uncommon condition associated with cutaneous atrophy, tearing of the skin and poor wound healing. this can be idiopathic but has also been associated with long term steroid treatment, hyperadrenocorticism and diabetes mellitus. the prognosis is variable - some cases resolve following correction of the underlying cause but in others the cutaneous atrophy is permanent. these cats should be kept indoors and protected from injury.
What are the flare factors for atopic dermatitis?
Atopic dermatitis is multifactorial involving skin barrier defects, allergic sensitisation, inflammation, microbial infections and other flare factors. Including ectoparasites such as fleas and trombicula autumnalis, staphyloccal and malassezia skin and ear infections, stress, behavioural therapy and perhomones. Excesses of temperatures and humidity, irritants or cleaning solutions etc.
What diet should be used in atopic dermatitis?
Animals with partial cutaneous adverse food reaction or food induced ad should avoid the offending items. many atopic animals benefit from foods supplemented with omega 3 fatty acids (important in epidermal lipid barrier formation, eicosanoid poduction and inflammation), omega 6 FAs and other nutrients.
Which topical therapies should be used in atopic dermatitis?
shampoo and leave on conditioner spray. percutaneous exposure to allergens - so physical washinig and removal of allergens likely to be helpful. Use emollients to counter driving. virbacs allermyl shampoo reduce pruritis used in whirlpool bath. contains linoelic acid, vitaminE and mono and oligosaccharides and piroctone olamine. Antimicrobial shampoos containing chlorhexidine, allerderm spot on contains ceramids and fatty acids that help restore the epidermal lipid layer structure. Dermoscent essential 6 is a st on mix of plant derived oils.
Which essential fatty acids should be used in atopic dermatitis?
polyunsaturated essential fatty acids particularly the n3 eicosapentanoic acid and n6 EFA gama linolenic acd.
How should atopic dogs avoid allergens?
Ideal way to manage an allergy is to avoid the alergen. unfortunately most cases of AD are associated with allergies to ubiquitous environemntal allergens such as house dust mites and pollens. these are difficult to completely avoid. house dust mite avoidance measures including avoiding bedrooms and bedding, vacuuming with a HEPA filtered cleaner, using hard floors, washing dog beds and using environmental flea sprays in the home. animals can be kept indoors during high pollen counts and washed off after being outside.
What is allergen specific immunotherapy?
ASIT is b eneficial in canine AD and in some cases of feline AD. should be specific and based on results of allergy testing trying to ensure that the allergens are clinically relevant. dose and freq need to be adjusted according to the individual patient. ASIT is not anti inflammatory treatment. It prevents flares associated with future exposure to the allergen. AD is also a complex disease with other abnormalities in addition to the allergy.
What is ciclosporin?
Treats canine and feline AD. Potent inhibitor of fT cells which have been imlicated in pathogenes of canine AD. Profound affects on immune system including antigen presentation ige production, mononuclear cell activity and development of inflammatory lesions. Metabolism is via cytochrome p450 system with subsequent biliary excretion. Withdraw treatment for up to two weeks either side of vaccination.
What is hydrocortisone aceponate?
A topical non halogenated diester glucocorticoid. Esters at the c17 and c21 ensure rapid absorption potent anti inflammatory action and metabolism within the derims into less active compounds minimising cutaneous and adverse systemic affects. HCA well tolerated, no changes to skin thickness, haematology, biochemistry or ACTH.
