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Dermatology Sonja Zabel, DVM, MS, DACVD Assistant Professor Dermatology Colorado State University How I Work Up an Itchy Dog Pruritus is a common problem for our patients in practice. Differential diagnoses for a young to middle aged itchy animal are diverse and include: endo- &ectoparasite infestation, bacterial- and Malassezia infections and allergies (flea bite hypersensitivity, airborne allergies, and adverse food reactions). Even so the signalment, history and physical exam may make already make us suspicious that our patient is allergic, these differentials need to be worked up, before we can proceed with our more specific allergy work up. Ectoparasitic diseases including flea infestation & flea bite hypersensitivity, scabies and cheyletiellosis. Even if the parasite cannot be identified using scrapings, a tape preparation etc. an ectoparasite trial treatment is indicated in suspicious cases (especially scabies). Dogs with flea infestation show variable signs of pruritus. Any pruritic dog should be combed for fleas, even if already on flea preventative. To require flea bite hypersensitivity, a dog needs to be repeatedly exposed to flea saliva. Once sensitized a few bites may be efficient for the animal to develop lesions, which consist of transient papules with crusts; alopecia, scaling, skin thickening, hyperpigmentation, lichenification - primarily dorsal lumbosacral area, caudal-medial thighs, ventrum, flanks. Lesions usually spare the head. These patients are also predisposed to acute pyotraumatic dermatitis (hot spots), secondary pyoderma and secondary seborrhea. Age of onset is 1-5 years (range: any age > 4 months). History and fleas or flea dirt upon examination and response to treatment are usually sufficient for diagnosis. Eosinophilia is common. Skin biopsies would show a superficial perivascular to interstitial dermatitis with eosinophils predominating. Immediate reactions to intradermal injection of flea allergen (80% of cases); 10% have delayed response (24 - 48 hrs), 10% have both immediate and delayed response. Anti-inflammatory doses of glucocorticoids, essential fatty acids and antihistamines (later two questionable benefits) can be used to decrease pruritus initially, while specific flea treatment is applied. It is important to treat as many stages as possible. In general, we look at potential for rapid knockdown and/or residual effects. Especially for animals with flea bite hypersensitivity, it is very important to not only treat the affected but all animals in the household as well as the environment. The affected animal usually requires more frequent treatment then recommended in medication inlet. Sarcoptic mange is an often intensely pruritic disease. The mites prefer skin with little hair (ear, elbows, abdomen, hocks) and are transferable to other species, including humans where they cause a pruritic papular dermatitis. Off host survival dependent on relative humidity and temperature - at room temp. but is usually 2 - 6 days. Early lesions pruritic, reddish papular, crusting lesions. The time from contact to initial signs is usually 1-2 weeks; within 3-4 weeks pruritus becomes markedly more intense. Atypical cases present with pruritus but no classical lesions (Sarcoptes incognito). Asymptomatic carriers can be seen. Sarcoptic mange is a mandatory rule out for any nonseasonal, intense pruritus Animals most likely show a positive pinnal-pedal reflex - if not present - it is unlikely to be scabies. A positive pinnal-pedal-reflex can also be seen with many other pruritic skin diseases such as atopy. The best way to find mites are multiple, broad scrapings. Sarcoptes scabiei lives in the superficial epidermis. In general, only small numbers of mites are present and it is difficult to find them on skin scraping. Even with numerous samples, negative results do not rule out scabies, since they are only found in 40-50% of cases. A line of mineral oil is placed broadly on the patient's skin and then scraped over a broad area, following the growth of the hair follicle. All oil and debris is scooped off the skin, placed in the middle of a glass slide, covered and microscopically examined. Mites can also be present in fecal flotation. Even on skin biopsy mites are rarely present and other changes are nonspecific - may suggest hypersensitivity. For this reason, trial treatment is recommended. Glucocorticoids can be used for symptomatic relief during first few days of therapy in conjunction with mite treatments including: 2 - 3% lime sulfur dips - weekly until pruritus resolved (4 - 6 weeks); safe, but messy. Ivermectin - 0.3 mg/kg per os once weekly for 4 weeks after a gradual increase of 0.05mg/kg on day 1, 0.1 mg/kg on day 2, 0.15 mg/kg on day 3 and 0.3 mg/kg on day 4. Monitor for lethargy, tremors, ataxia and mydriasis. , if any of these occur at lower doses, a change of medication is indicated. Milbemycin oxime - 2 mg/kg twice weekly for 4 weeks. Selamectin - three topical therapies, separated by 2 weeks Advantage Multi- three topical therapies, separated by 2 weeks All animals in the household need to be treated and all bedding should be washed and dried at highest setting possible. Cheyletiellosis most commonly presents as dorsal scale (walking dander), with variable pruritus (absent to severe) and may be see with higher incidence in immunocompromised individuals. Several diagnostic options are available, which include the most commonly used Acetate tape preparation which is more accurate than multiple broad, superficial skin scrapes. Clear scotch tape is pressed on the hair surface and the skin collecting scales and debris. After that tape has been placed on a glass slides it can be examined microscopically. Also, fleas, flea feces and eggs, lice, nits and miscellaneous parasites such as Dermanyssus, Walachia etc. can be found with this method. Other diagnostic methods include fecal flotation and combing of material into a Petri dish and examined with a hand lands or under the microscope, to find Cheyletiella mites. All in contact dogs and cats should also be treated using treatments like: Lime-sulfur - once weekly for 3-6 weeks (until pruritus/scaling completely resolves) Fipronil - q 2-4 weeks for 2-3 treatments Selamectin - q 2-4 weeks for 2-3 treatments Ivermectin - 0.3 mg/kg per os once weekly for 4 weeks after a gradual increase of 0.05mg/kg on day 1, 0.1 mg/kg on day 2, 0.15 mg/kg on day 3 and 0.3 mg/kg on day 4. Monitor for lethargy, tremors, ataxia and mydriasis, if any of these occur at lower doses, a change of medication is indicated. Every lesional, itchy animal should be evaluated for secondary bacterial and Malassezia skin and ear infections, using standard procedures (i.e. impression smears, tape preparations). Clinical Presentations: Surface pyoderma - acute, moist, pyotraumatic dermatitis (Hot spot); fold pyoderma, mucocutaneous pyoderma Superficial pyoderma (folliculitis) - papules; pustules; focal areas of erythema with variable crusts and alopecia; epidermal collarettes (superficial spreading pyoderma), mucocutaneous pyoderma. Deep pyoderma - focal areas of skin thickening, inflammation, crusting, serosanguinous or purulent exudates; draining tracts Diagnosis:
Equipment needed includes glass slides, cover slips, stain and a microscope. The various techniques can be used for cytological examination, including impression smears, swabs, scrapings, acetate tape preparations and a fine needle aspiration. All samples can be stained with modified Wright's stain (diff quick). Samples from waxy or moist areas, ear swabs, or when yeast is suspected are to be heat fixed prior to staining. When neoplastic cells are suspected, gram staining is preferred. We use a 0-4 scale for quantization of organisms. When we evaluate cytology of an ear swab, normal ears are noted to have an occasional Malassezia or bacteria per high-power field (hpf). 1+ would be 1-3 organisms/hpf, 4+ would be wall-to-wall organisms. Cytologies are evaluated for the presence of rods or cocci, yeast, filamentous bacteria and inflammatory cells. Diplococci suggest the presence of staphalococcus species. Notation is made of the presence of intracellular bacteria as these are more likely to be contributing to the pathogenesis of the inflammatory condition. Interpretation of yeast numbers is controversial in that individuals may develop a hypersensitivity to Malassezia in which case relatively small numbers may be problematic. Therefore if 1-2 Malassezia per hpf are seen and clinical signs suggest yeast infection, trial treatment should be performed. Impression smears: This sampling technique is mainly used for fluid-containing lesions. The edge of the slide (papules, crusts, erosions, ulceration, draining tract, etc.) or the tip of the needle (pustule cytology) is used to remove overlying crusts or open pustules; the slide is then pressed directly against the lesion. Apply pressure to the back of the slide to facilitate a good impression smear. While applying pressure, place your index finger on the under side of the slide to prevent the slide from breaking. Once the collected sample dries, Diff-Quick (modified Wright's stain) is used before the sample is examined microscopically. Swabs: This technique is most often used for samples taken from draining tracts, ear canals, or interdigital webs. The cotton tip is moistened with saline, rubbed over the skin surface and rolled onto a glass slide. Scrapings: These are used to sample underneath crusts and peeling stratum corneum. Also, nails with brownish discoloration are scraped in order to find possible yeast organisms. The collected material is then gently wiped on the glass slide, heat fixed, stained and examined. Acetate tape preparation: Clear Scotch tape can be used for dry surface areas or areas hard to sample such as interdigital webs. Acetate tapes are only to be used when yeast infections are suspected as the background material on the Scotch tape makes bacterial evaluation difficult, especially cocci. A piece of tape a little shorter than the length of the glass slide is pressed firmly on the surface of the lesion and stripped off. This procedure is repeated about three times for the same general area. The tape is then placed on a glass slide containing a drop of Diff Quick (blue stain). A paper towel is placed over the tape and pressure is applied to remove excess stain. The slide is then examined under oil immersion. Bacterial culture and susceptibility testing: Bacterial c & s should be considered in any skin lesion (pustules, abscess, cellulitis, superficial or deep pyoderma, or acral lick dermatitis) for which bacteria are considered a differential diagnosis but response to appropriate antibiotic therapy is lacking. Ideally, samples should be collected from unbroken pustules by needle aspirates or by biopsy. Every attempt should be made to minimize surface contamination of sample. Without prior preparation, unbroken pustules are lanced with a scalpel blade and purulent material is harvested for culture. When taking biopsies for culture, the sample is harvested with a smaller punch (4mm dia) the superficial surface is trimmed away with a sharp scalpel blade to minimize surface contamination and the tissue is placed in transport media. Therapy:
Causes:
Easy and fast diagnostics for dermatophytosis include a Trichogram and Woods lamp examination. Since neither of these diagnostics are 100% diagnostic, a dermatophyte culture is required in all cases. The Wood's lamp should be turned on 5-10 minutes prior to use to ensure the correct wavelength. Positive fluorescence is yellow to green in color and the complete hair shaft fluoresces. False positive results can be caused by several medications, debris, and fabric fibers etc. Fluorescent hairs are harvested for trichogram evaluation and fungal cultures. Microsporum canis is the only dermatophyte that fluoresces. Only 30-40% of this species will fluoresce. A positive fluorescence is highly suggestive of dermatophytosis but negative results do not rule it out. For a Trichogram hair is carefully pulled to minimize trauma to the hair and then placed in mineral oil or KOH on a glass slide, covered and examined under low power. Preparations are examined for dermatophyte arthrospores (or demodex). Broken hairs are suggestive of self-inflicted alopecia or dermatophytosis. Using KOH has the advantage that it "clears" the background and makes it easier to evaluate the sample but samples have to sit for 5-20 minutes and the slide has to be warmed. This preparation is, therefore, time consuming. There are several culture media available. These include DTM (dermatophyte test medium) and rapid sporulating medium (RSM). Both contain color indicators. Hairs and crusts are taken from the periphery of a lesion and are gently impressed on the surface of the culture medium. We prefer using a derm duette (combination of DTM and RSM). Material from the same area is placed on each side of the culture dish. The well is filled with water and the culture is kept in a warm, easily accessible area without direct sunlight as UV light can disturb fungal growth. McKenzie Toothbrush Technique is used for suspected asymptomatic carriers or animals on treatment which are recultured for follow up. The toothbrush is combed through the coat over the entire animal. Gathered hair and debris are impressed on the culture media and the bristles of the toothbrush are gently impressed in the superficial layers of the media. Also, bristles can be cut off and cultured with the hair and debris. Dermatophytes grow white or buff colored (pigmented colonies are contaminates). In case of dermatophyte growth, media show a color change within 24 hours following colony growth. Because dermatophytes metabolizes media proteins into alkaline by products a color change occurs. Saprophytes prefer carbohydrates and only metabolize proteins once the carbohydrate source is depleted. In this case, the color change is noticed in 3-7 days. We circle and date areas of growth when first noted to facilitate the interpretation of changes. Every culture is monitored daily for 3 weeks. Some dermatophytes will not change the media color. To confirm identification, all suspect dermatophyte colonies should be speciated. Speciation offers epidemiologic insight as to the source of infection. Hyphae are picked with Scotch tape and placed on a glass slide with a drop of lacto phenyl cotton blue. The preparation is examined for characteristic macroconidia. Dermatology reference sources such as Muller and Kirk's Small Animal Dermatology 6th Ed., WB Saunders, Philadelphia, can be used to help with identification. Only mature colonies start producing macroconidia (7-10 days after first growth). If these structures are not seen initially, specification should be repeated every 2-3 days. Rapid-sporulating media has been marketed to enhance sporulation. This has not been proven in one study. Demodicosis can present in several forms. The localized or focal form of demodicosis presents with less than 5 discrete areas of alopecia/inflammation/ scaling; most commonly noted over head and extremities. Spontaneous remission follows in 90% of cases within 6-12 weeks. Generalized Juvenile Onset occurs in dogs less than 18 months of age at onset. They have a genetic predisposition and there is a higher incidence noted in purebred dogs. A T cell defect that allows for mite proliferation followed by immunosuppressive factors produced by the mite itself is thought to be causing this disease. Secondary bacterial infections contribute to immunosuppression. Dogs may grow out of tendency to have generalized demodicosis. Clinical signs are usually asymmetric, multiple focal to widespread areas of alopecia, with variable degrees of scaling, inflammation, crusting, erosion, ulceration. Generalized Adult Onset is caused by an acquired immunoinsufficiency; most commonly hyperadrenocorticism (endogenous or iatrogenic), hypothyroidism, some severe intercurrent systemic disease (e.g. neoplasia). However, as many as 30% of cases are idiopathic. Clinical signs are as for focal or generalized disease as noted above. Demodex mites live deep in the hair follicle and require a deep sample for diagnosis. A glass slide is prepared with a drop of mineral oil. A small amount of the oil should be placed on the scalpel blade and after the skin has been squeezed to extrude mites from the hair follicle the lesion can be scraped following the growth of the hair follicles. Only a small surface area has to be scraped but the sample has to be deep causing capillary bleeding. The obtained material should be scooped out and placed on the middle of the glass slide. Oil and material should be covered with a cover slip before microscopic examination. In every case multiple skin scrapes should be taken. The number of eggs, larvae, and nymph and adult mites (dead or alive) should be documented to be able to evaluate treatment at recheck. In Sharpei, dogs with chronic demodectic pododermatitis skin scrapings and hair plucks might fail and mites might only be found on biopsy. If deep skin scrapes cannot be performed, for example because the lesions are particularly hairs can be plucked, placed on the slide with mineral oil covered with a cover slip and examined microscopically. This test is may not be as accurate as deep skin scrapings unless hair plucks unless moderate numbers of hairs are plucked from several lesional reads. If demodex mites are not found deep skin scrapes should be performed. The focal form of demodicosis does not require therapy. If inflamed and pruritic the use of systemic antibiotic may be helpful. The juvenile Generalized Form is often secondarily infected and requires systemic antibiotics for 1-2 weeks beyond complete clinical resolution of pyoderma signs. Treatment options include: Amitraz (Mitaban, Upjohn; .025%, 250 ppm) - for mild to moderate cases dip every 2 weeks. For moderate to severe cases, dip every week. Higher cure rate with more frequent dips. Toxicities: Depression following dipping common; only of concern if moderate to severe; more common in small breed dogs. Vomition, diarrhea, skin irritation. Can see coma/death. Recheck monthly for 3 months after apparent resolution. Cure rate - 75%; Relapse rate 10 - 15 %. These patients may be maintained on maintenance dips every 2 - 8 weeks. Alternative therapies:
Or monthly applications of Promeris. Once all these differentials are ruled out or are appropriately treated further allergy work up should be considered to address the underlying problem of the patient. Allergies are commonly seen skin problems in animals and include: flea bite hypersensitivity, airborne allergies (atopy), and food adverse reactions (FAR). Less frequently contact allergies can be seen. In areas with fleas, atopy is the second most common hypersensitivity disorder of dogs. The initial clinical sign in allergic (FAR or atopy) animals is pruritus, usually involving the face, paws, distal extremities, anterior elbows and ventrum. Pruritus can either be seen with no visible lesions, slightly erythematous macules, or more diffuse erythema. Self trauma, chronic inflammation, and secondary bacterial pyoderma or Malassezia dermatitis may result in complete or partial alopecia, salivary staining, papules, pustules, hyperpigmentation and lichenification. Other clinical signs can include conjunctivitis, rhinitis, asthma, seborrhea, and diarrhea. A thorough history is necessary for a good work up for allergies. It is important to note the duration of the disease, how it was treated in the past and if treatment helped, if other animals in the household are affected, what kind of diet the dog is on, if a strict diet trial has been done and if so, how long it was fed, and if it was a commercial or a home cooked trial. Allergies are diagnosed based on history, clinical signs and rule out of other differential diagnoses. Atopic dermatitis (airborne allergies, atopy) is diagnosed by ruling out all other differential diagnoses including food adverse reactions. For this reason, a workup for food adverse reactions should be performed once other differential diagnoses have been ruled out. Food adverse reactions are unwanted and unpredictable reactions to dietary allergens. They can be divided into two categories: food allergy and food intolerance. Food allergies are immunologic reactions to food components. Food intolerance is any non immunologic reaction to foods. Neither diagnostic tests are available to distinguish between these two categories nor can they be told apart by their clinical signs. Adverse reactions to food are estimated to contribute to about 10 % of allergic skin disorders in the dog. In the cat the condition is described to be relatively more common than in dogs. Dietary allergens are usually basic food ingredients like beef, chicken, lamb, pork, fish, egg, milk, rice, wheat, oatmeal, corn, soy etc. Additives In commercially available diets have also been hypothesized discussed as possible allergens, but documented cases are rare. Exposure to food allergens occurs in the gastrointestinal tract, but is also suggested as contact through the skin and inhalation. Dermatologic signs are present in 80-90% of the food allergic animals. Respiratory signs (i.e. sneezing, reverse sneezing) are rare, while gastrointestinal signs (i.e. vomiting, diarrhea) have been observed in 10-15% of the cases. Dogs with food adverse reactions show signs year around. In general dogs develop food adverse reactions at a young age, but these can develop at any age. Even so serologic testing for food allergens is commercially available; so far the only reliable diagnostic test for food adverse reactions is a strict elimination diet of 6-12 weeks duration (once the secondary pyoderma resolved). The diet ingredients are chosen based on the patient's dietary history. One protein (i.e. duck, rabbit, ostrich, kangaroo, pinto beans, tofu- can be obtained at a wild game sale) and one carbohydrate source (i.e. potato, yam, oats, rice) the patient had not been fed before are chosen and fed exclusively for the duration of the diet trial. No commercial treats, flavored medications (i.e. heartworm), rawhide chews, flavored toys are allowed, but the owners can prepare their own treats based on the ingredients in the diet (i.e. homemade potato/yam chips or homemade jerky) A diet trial can be home prepared or commercial (dry and/or wet). A commercially available is more convenient for the owner, not as time consuming and in most cases less expensive, but also not as effective and a home prepared diet trial is still considered the standard of care diagnostic tool to work up food adverse reactions. Another, newer method for food trailing is the use of hydrolyzed diets. In these commercially available diets protein molecules will be enzymatically broken down to smaller peptide fragments which are less allergenic and more digestible. In general, if dietary proteins are properly digested prior to contact with the GI mucosa, they will not activate the immune system. So far, no higher success rate has been found using hydrolyzed vs. commercially available novel protein diets. It is important for the owner to understand that which ever method they choose, it has to be strictly maintained, as one little piece of cheese etc. will disrupt the whole diet trial. In order to determine if the patient has food hypersensitivity pruritus has to be evaluated on a regular/daily basis. The owners may see complete resolution or significant improvement of pruritus. A few of the patients will show improvement within the first 3-4 weeks on the diet trial, most show improvement within 6-8 weeks and a few may take up to 12 weeks or longer to show complete resolution of pruritus. Every dog that had been on a strict diet trial for at least 6-12 weeks has to be re-challenged with his maintenance dog food and treats at the end of the diet trial, to evaluate the diagnostic procedure. Most dogs with food adverse reactions will develop pruritus within 2 days to 2 weeks, after re-challenge. Once it is established that the patient has food adverse reactions, a sequential diet re-challenge will be performed (one ingredient at a time) to determine which foods have to be avoided. Based on these results a commercial, well balanced diet is then chosen as maintenance diet. As this is a lot of new information for the owner, it is advisable to prepare a handout for the owners to take home and to perform a follow up call 2-3 days after the appointment to answer possible questions. If the pruritus did not resolve during the home cooked diet trial and the patient did not worsen during the 2-14 day re-challenge, the dog does not have food adverse reactions and by ruling out all other differential diagnosis, atopic dermatitis has been diagnosed. Please note that airborne allergies cannot be diagnosed based on intradermal skin test. This is a diagnostic tool to identify single airborne allergens (i.e. tree-, grass, weed pollens, house dust mites, and mold spores) once the diagnosis of atopy has already been made. Either serologic testing for airborne allergens or intradermal skin testing (IDST) can be performed to identify allergens. Most dermatologists consider IDST the gold standard, but this is a time consuming procedure and allergens are expensive and have a relatively short shelf life in the refrigerator, therefore IDST is mainly performed by specialists. If you refer a patient for IDST it is important to note that some medications can interfere with the skin test results and have to be discontinued prior to skin testing (see table). Please note that antibiotics and topical antimicrobial and antipruritic shampoo's can be used the whole time. If an owner does not want to be referred to a Dermatologist or the next specialist is far away, serologic testing can be performed to identify allergens. There are several commercial available tests on the market. In general it is preferable to use a test that tests for single allergens and not of allergen groups. Please note, that most companies recommend discontinuing glucocorticoids for some time before serologic testing is performed. Based on the results allergy solution can then be ordered and the patient can be started on allergy shots. Most companies will make recommendations on which allergens should be included in the allergy solution. In general the allergens are chosen based on the patients history and the environment it lives in (if allergens are prevalent). So far allergy shots are the only curative treatment for airborne allergies. We have a ~60% success rate with this treatment and it can take 3-12 months for this treatment to help the patient. The allergens are sent out with a detailed information sheet on the injection procedure, possible side effects, allergen storage instructions and a general injection schedule. Symptomatic treatment can be used to make the patient more comfortable, while we wait for beneficial effects of the allergy shots. Symptomatic treatment includes medications like antihistamine trials, fatty acids, shampoo's, topical and oral steroids. Common medications to be discontinued prior to IDST:
Should an owner not be interested in intradermal skin testing and hyposensitization, or should this treatment fail to benefit the patient, cyclosporine (Atopica®) may be a good treatment alternative. Cyclosporine (CsA) is a cyclic oligopeptide which exhibits potent immunosuppressive properties by its ability to block transcription of cytokine genes in activated T cells. It has been used for more than a decade for preventing organ transplant rejection in humans. More recently, it has been approved in human medicine for the treatment of immune-mediated diseases such as rheumatoid arthritis, psoriasis and atopic dermatitis. In veterinary medicine, CsA has also recently found to be highly valuable in dogs for the control atopic dermatitis (5mg/kg/q24hrs) and other immune-mediated skin diseases. The therapeutic activity of CsA is related to inhibition of the inflammatory process observed in the allergic reaction. CsA inhibits T-lymphocyte activation, eosinophil recruitment to the sites of allergic inflammation, the lymphocyte-activating functions of antigen-presenting cells, such as Langerhans cells, and cytokine secretion by keratinocytes. Finally, CsA inhibits IgE and mast cell-dependent cellular infiltration at the sites of cutaneous inflammation. Immunosuppressive effects are reached by stimulating cells to secrete transforming growth factor-? (TGF-?) Side effects include intermittent soft feces, diarrhea, vomiting, inappetence, gingival hyperplasia and papilloma like lesions. However, hematology and biochemical parameters remained within normal limits. Maximal clinical effects (decrease in lesional and pruritus scores) are reported in dogs with canine atopic dermatitis to take 2-4 months To enhance Cyclosporine levels in dogs, this drug is commonly dosed with ketoconazole (5-10mg/kg q24, with full meal, 2 hrs prior to cyclosporine administration), which inhibits both cyclosporine metabolism via CYP3A enzymes and biliary and trans-GI-epithelial transport via P-glycoprotein resulting in decreased clearance and consequent increased levels of cyclosporine. This Cyclosporine/ketoconazole drug combination is not only pharmacologically beneficial but is also financially advantageous, as CyA is expensive; however, this dosing does can lead to large interpatient variability. Absorption is supposed to be best when medication is administered on an empty stomach, however one clinical study did not show clinical difference if medication was given with full meal, which decreases the chance for soft stool, vomiting and diarrhea. Example for use of cyclosporine/handout for clients at CSU: A) Initial treatment: Atopica® (Novartis) 5mg/kg q 24 hours: 1st & 2nd day: Give ¼ of full dose once daily WITH meal 3rd & 4th day: Give ½ of full dose once daily WITH meal 5th & 6th day: Give ¾ of full dose once daily WITH meal 7th & 8th day: Give full dose once daily WITH meal (small amount of food can be given to administer capsule). Dosing steps will be determined by available capsule sizes (10mg, 25mg, 50mg and 100mg capsules). If vomiting, diarrhea or lethargy occurs at any time, please stop medication and contact us. 9th & 10th day: Give full dose once daily WITHOUT food (2 hours prior to full; meal) for better absorption Recheck 4 weeks after initiation of Atopica® therapy. Examples based on weight:
B) At four week recheck, ketoconazole (based on blood biochemistry results) with be added: For Ketoconazole:
Rechecks will be established base on clinical response. D) Possible further decrease in dose depends on clinical response, but may include every 3rd, 4th, 5th day etc. treatment.   |