----start--- gomez derm 11/30/98 Seborrhea Lecture: [note little shar pei logo at the bottom of the introductory slide] seborrhea can be a bit confusing; shouldn't be, but can be. all exam questions are from the handout; if something seems unclear, refer to the handout; the handout is 3 pages long, the last disease is on the back of page 3, make sure to turn that page over. at least one question will be about those diseases. Seborrhea is a clinical sign, not a disease. when people talk about seborrhea, it's similar to talking about dandruff - it's a clinical sign, not a disease per se. slide: seborrheic skin - dry form. you see flakes on the skin and hairs. we see this in dobermans, GSD - seborrhea sicca, dry form. what is seborrhea? -a keratinization defect manifesting as excessive scale formation of the skin and haircoat -any abnormality in epidermal maturation, keratinization, lipid formation (important for stratum corneum!), cell cohesion, or desquamation can lead to this disorder (seborrhea). read handout blurb on epidermal maturation. don't know specific protein functions but have fair idea about how epidermis esp stratum corneum matures. two separate entities: primary seborrheic problems and secondary seborrheas. primary ones are due to an inherent defect in maturation or epidermopoiesis or whatever. epidermis is being formed, something is wrong, you get primary seborrheic defects. Primary diseases causing generalized seborrhea: -primary idiopathic seborrhea: most common - cockers, WHWT -sebaceous adenitis - sebaceous glands are attacked - resembles autoimmune dz, but considered primary b/c we think there is a problem with the glands, making them fill up and start leaking sebaceous material and keratin, causing inflammatory rxn. see scaling of head, back. probably will see this. is interesting, can probably make a dx on clinical suspicion and bx. -zinc responsive dermatosis: two forms. not on test. seen in northern breeds - husky, malamute - most often - true inherited defect causing scaling around nose, mouth, eyes, perineal area - all mucocutaneous junctions. we've also seen this form of the disease in a cocker spaniel. these dogs do better when supplemented with zinc, usually, but may relapse even on zinc. those three most common other primary seborrheic defects: vitamin A responsive dermatosis - responds to vitamin A tx color dilution alopecia, follicular dysplasia: slide of black and tan dobie mix who is missing the black hairs and has seborrhea. this is rare. canine ichthyosis - seen from time to time schnauzer comedo syndrome - dorsal distribution of comedones. primary diseases causing localized seborrhea: idiopathic nasodigital hyperkeratosis - frequently seen - slide - scaling at margins of footpads. canine acne - frequently seen canine ear margin dermatosis - ear margins have fine little scales on them; mimics scabies - if pruritic, first ddx is scabies. lichenoid-psoriform dermatsomething... secondary causes of seborrhea: anything else :) we differentiate b/w primary and secondary b/c primary generally inherited disorders that in some aniamls are very hard to tx. there are many dogs put to sleep b/c owners can't handle the primary seborrheic problem; also gets expensive to tx b/c you have to use those synthetic vitamin A/Retinols which cost hundreds of bucks a month. so you have to tell people if you think it's a primary dz to deal with for the life of the dog, or a secondary dz which will go away after primary problem is fixed. secondary causes: demodex scabies dermatophytosis cheyletiellosis fleabite allergy food allergy atopy hypothyroidism hyperadrenocorticism pemphigus folliaceous cutaneous lymphoma nutritional deficiencies environmental influences pyoderma slide: spaniel with pemphigus folliaceous who looks similar to the zinc responsive dermatosis dog. easy to confuse slide: Golden retriever who came in age 10, large flakes and scales, has seborrhea secondary to cutaneous lymphoma - whole side is bald. the big thing is to tell if it is primary or secondary. signalment: breed - some are more prone to primary keratinization defects: sebaceous adenitis - in any breed but esp poodle, akita, viszla - if you see sebaceous adenitis in your practice, 50% will be in poodles (the number one breed). but other breeds get it too. cocker spaniels get a lot of primary defects - nasodigital hyperkeratosis, other. age is also helpful - most primary defects show up in very young dogs - newborn through two years. middle age to older dogs usually have secondary causes of the scaling. one caveat to that - the nasodigital hyperkeratosis occurs in any breed, and can be seen later in life. sebaceous adenitis usually occurs b/w 2 and 6 years of age, too. history: age of onset did the owner notice scales first, or was there pruritus or other lesions first? if scale was first, consider primary defect. sometimes allergic diseases cause major seborrheic problem. if scaling is only sign, though, consider primary. if scaling occured first then itchiness, probably has secondary pyoderma. what was response to previous treatment? clinical signs: mild to severe dry or waxy scale s.oleosa - waxy, large, yellow, adherent scales that stick on the animal. these dogs have lost hair, and have large yellow waxy scales - seen in primary idiopathic seborrhea s. sicca - scales and flakes are distributed to the haircoat rather than sticking to skin, easily brushed off, very dry. also seen in primary idiopathic seborrhea, but usually in GSD, doberman, akita, irish setter. that occurs due tothe very dry skin and haircoat. those dogs tend to be much easier to manage than the seborrhea oleosa dogs, who have more problems, lifelong labor intensive management requirements. most people bring them in b/c they smell bad. some animals have a seborrheic odor to their skin and haircoat - often an odor of yeast, b/c oily seborrhea predisposes to malasezzia. follicular casts and comedomes are also seen - in sebaceous adenitis dogs - if you pluck out a hair, it will come out easily, and on the end of the hair will be a coating of white scale - a follicular cast. almost a pathognomonic sign. if dog is right age, breed, and has this - probably ahs sebaceous adenitis. sometimes occurs with pyoderma but really more with s.adenitis. so you'd want to biopsy this. comedomes are helpful - schnauzer comedome syndrome, esp with dorsal distribution. if dog is potbellied, has these things on the belly, consider cushings. diagnosis: really important to differentiate b/w primary and secondary seborrheas primary are lifelong management problems can lead to death of dog b/c they are so hard to deal with - smell, scaling, work, expense to take care of these dogs. diagnostic tests include: flea comb, skin scrape, fungal culture, impression smear, C&S, CBC/Chem/T4, tape prep, fecal, IDST, food elimination diet, biopsy. biopsy is important - can dx sebaceous adenitis, canine ichthyosis, autoimmune dz... skin biopsy: send to dermatopathologist take bx of early lesions and well developed lesions can pinpoint or rule out diseases at least three representative samples should be obtained try to take a sample of normal looking skin, too - often helpful topical therapy with sebaceous adenitis, this is the number one tx shampoo - most important many types are available, including moisturizing, benzoyl peroxide, chlorhexadine, sulfur-salicylic acid preps, and tar based shampoos. all of these need to be left on the skin for at least 15 minutes. for primary seborrheas and often with secondary, use 2-3 x per week for 3-4 weeks, then weekly. benzoyl peroxide is great for adherent scale, follicular plugging chlorhexidene good for pyoderma sulfur-salicylic acid is keratolytic - removes top of stratum corneum, smooths it out, affects the basal cell layer tar shampoo also affects basal cell layer - allows it to go through stratum spinosum/granulosum in more normalized way many seborrheic dogs have increased turnover time - normal 22 days; these dogs much shorter times like 4 days. rinses/conditioners/gels and ointments can all help gel/ointment very helpful for localized problem, not so much generalized problem. benzoyl peroxide: keratolytic removes cells from stratum corneum antimicrobial follicular flushing very drying salicylic acid keratolytic - removes stratum corneum keratoplastic - normalizes cell kinetics synergistic iwth sulfur non-drying sulfur-salicylic acid is number one choice for these dogs - less drying than benzoyl peroxide or tar shampoos. tar - keratoplastic, normalizes epidermal cell kinetics at stratum basale. very drying. smells yucky and is ugly. good for dogs with really greasy seborrhea oleosa. use it very short term, then switch to sulfur/salicylic acid shampoo humectants/emollients: esp in dogs with primary seborrhea, very useful to moisturize stratum corneum. increases hydration of stratum corneum propylen glycol, lactic acid = humectants suspensions of oil in water - emollients you can spray them with an emollient, let it soak a couple of hours, then wash them - that is very helpful for sebaceous adenitis cases. systemic tx: useful for any seborrhea. important. if youhave the stratum corneum disrupted, as you do in seborrhea, you can get cracks, fissures, pyodermas. so: systemic abx to clear any secondary pyoderma or tx yeast infection seen with oily seborrhea retinoids - used in tx of primary keratinization defects - primary idiopathic seborrhea, sebaceous adenitis, canine ichthyosis; topical retin A in canine ear margin dermatosis or chin acne. systemics very helpful but expensive; liver side effects, KCS effect, bone changes can occur. so when using retinoids, consider $$$, also need pre-tx liver enzymes and schirmer tear tests, and rads, and follow up monthly x 3-4 mos, then go to q 3-6 mos; rads every 6-9 mos to ensure no bony changes. fatty acid supplements - may help some cases of dry seborrhea caused by poor nutrition or low humidity response to abx therapy: if these dogs were on meds before, you ask how they did... 1. scaling resolves completely on abx - not a primary seborrhea 2. scale remains and other signs also continue (pruritus, hairloss) - consistent with a secondary seborrheic problem. probably allergy. 3. scale is the only sign left after tx - consistent with primary keratinization defect a word about steroid use: don't use them. you may find times with primary idiopathic seborrhea in cockers when you need to use them to control pruritus, but really other than that do not use them. steroid use must be limited to those times when you know the dx, and you want to decrease the inflammation with short term steroids. steroids make seborrhea worse by changing skin thickness and changing hair follicles and sebaceous glands. just use short course, taper quickly. Primary idiopathic seborrhea: important concept, this disease. this is the big disease with seborrhea in the name of it! it is a type of primary generalized seborrhea. it is the most common and most studied keratinization defect in dogs. thought to be inherited; cockers, springers, WHWT, dachshund, basset hounds. irish setters, GSD, lab, dobe - get a dry form. not representative. cocker spaniel and WHWT get worst form. this WHWT has erythema on legs, neck - young puppy. often this disease is confused with atopy which is the number one ddx after you r/o parasites. number two is food allergy. but if you put him on food elimination diet you rule that out. with atopy it's harder b/c these dogs tend to have positive skin tests b/c they have abnormal skin. but they do not respond to hyposensitizatin and can bx then and find it. often alopecic, lichenified skin with hyperpigmentation changes. early onset common. often have malassezia infections. dx - age, breed, history and elimination of any secondary cause by diagnostic testing. onset 6 mos to 3 years. onset is severe - itchy, thick, lichenified skin occurs rapidly. with atopy more often gradual, seasonal onset. PIS dogs tend to have it all the time, chronic skin problem. tx: no cure. control is the objective. seborrhea sicca: use moisturizing shampoos, conditioners seborrhea oleosa: sulfur/salicylic acid shampoo retinoids: Tegison (replacement - psoriatane - more expensive) antibiotics periodically many baths many dogs put to sleep after a year or two b/c owner can't deal with it anymore. idiopathic nasodigital hyperkeratosis: simple, easy dz - dry nose, dry feet. cocker spaniels, springer spaniels young dogs or older animals clinically, present with thick adherent scale on planum nasale or footpads; may also see cracks, fissures, and ulcerations. dx on history and PE findings. as long as no other systems are affected, you can know what it is. pemphigus folliaceous may resemble this - if bleeding, ulcerations, fissures -s hould biopsy; otherwise just try to treat. tx: wet dressings to nose and feet in evenings; then rub with petroleum jelly; kerasolve gel, retin A creme, abx or steroids in cases of severe secondary infection or inflammation. chin acne - just read about this. common problem in dogs/cats. around chin, top of muzzle sometimes. starts around sexual maturity at 6-9 mos; often in short coated breeds of dogs. may be very itchy; rub feet/nose/chin on furniture, pushing hairs into dermis and making it worse. may be self limiting, or persist into adulthood. ---end---