Condition	Description	Symptoms	Diagnosis	Treatment
Allergic and irritant contact dermatitis	An allergic reaction following exposure to antibiotics applied to the skin; metals such as nickel; materials such as rubber, wool, and plastic; and chemicals such as dyes and carpet deodorizers; or inflammation caused by irritating substances such as poison ivy. Generally requires multiple exposures.	Red skin and small bumps or blisters on the areas of skin that are sparsely haired and directly exposed to the offending substance, itching; hair loss in chronic conditions	Patch test, exclusion trials	Restrict exposure to the allergen or contact irritant in the cat's environment; steroids, antihistamines
Atopy (allergic inhalant dermatitis)	Allergic reaction to something the cat inhales such as pollen, house dust mites, and mold	Licking of feet, inflamed ears, itching, redness, and hair loss; sometimes development of infection or hot spots	Intradermal or serologic (blood) testing for allergies	Reduce exposure to allergen (what the cat is allergic to), steroids, fatty acid supplements, biotin, antihistamines, shampoos, immunotherapy
Bacterial infection (pyoderma) See Folliculitis	Often occurs as a result of another condition such as a parasitic, allergic, or hormonal condition
Bee, wasp, hornet stings	Skin reactions can vary dramatically in severity	Immediately after the bite, see swelling, redness, pain, possibly itching; subsequently may develop extensive ulcers with draining; may develop hives or anaphylaxis	History, physical exam	Antihistamines, steroids; wet dressings if ulcerated; protect the area from self-inflicted trauma
Cheyletiella (rabbit fur mite) mange	Infection with the Cheyletiella mite	Itching, scaliness; some hair loss, if severe	Skin scraping and microscopic examination - the mite is often very difficult to find	Pyrethrin
Chiggers (harvest mites)	Seasonal disease caused by larvae of the chigger	Itching, bumps usually on feet, abdomen, folds at base of ears	Visualization of mite larvae or microscopic examination of skin scraping	Pyrethrin
Demodectic mange	Infection may be localized or generalized; the generalized form occurs in cats who have a deficient immune system	Hair loss, scaliness, redness, sometimes itching	Skin scraping and microscopic examination	NO Steroids! Rotenone, dilute Amitraz (Mitaban) dips, lime sulfur dips, ivermectin (off-label use*)
Drug or injection reaction	Rare skin reaction to a drug which is inhaled, given orally or applied topically; more common with penicillins, sulfonamides, and cephalosporins; usually occurs within 2 weeks of giving the drug	Can vary widely and may include itching, hair loss, redness, swelling, papules, crusts, ulcers, and draining wounds	History of being treated with a drug, symptoms, biopsy	Discontinue offending drug; treat symptomatically
Ear Mites	Infection with Otodectes	Intense itching of ears, redness, dark crumbly discharge in ears	Direct visual or microscopic examination of ear discharge	Clean ears and apply medication containing pyrethrin (Ear Miticide)
Eosinophilic plaque	Part of the common eosinophilic allergic syndrome in cats which includes eosinophilic granulomas, miliary dermatitis, and rodent ulcers	Intense itching; raised, oval, oozing, and possibly ulcerated lesions; may be single or multiple; often on abdomen and thighs	Microscopic examination of swab from lesion, biopsy, CBC (find increased eosinophils); look for underlying cause, e.g., parasites, food allergy, atopy	Treat underlying cause if found; corticosteroids; fatty acid supplements; immunosuppressive drugs in severe cases
Epitheliotropic lymphoma (mycosis fungoides)	Rare cancer of T lymphocytes seen in older cats; may be associated with FeLV	Redness, itching, scales, ulcerated nodules	Needle or other biopsy	Poor response to treatments which include chemotherapy, surgical removal, retinoids, fatty acids
Feline acne	Skin condition of unknown cause which may occur as single episode or continue as chronic condition; most commonly seen on the chin; can develop into a more serious, deep infection if not treated	Comedones (black heads) on lips and chin, later developing pustules and small nodules; may itch - especially in chronic cases; chin may become swollen; can become secondarily infected	Physical exam; tests to rule out underlying causes or diseases with similar symptoms; skin biopsy	Mild: antiseborrheic shampoos, antibacterial creams, topical Vitamin A; Severe: antibiotics, fatty acids, retinoids (use with caution, can be irritating)
Feline pox	Viral disease; outdoor cats more commonly affected; presumably transmitted by bite wounds	Nodule at the site of a previous bite wound; progresses to multiple nodules which may ulcerate and have crusts; may itch	History, physical exam; biopsy; specialized testing to identify the virus	Lesions usually resolve in 3-4 weeks; antibiotics for any secondary infection; antihistamines for itching; NO steroids; in some cats, lesions progress and do not respond to treatment
Flea allergy dermatitis (flea bite hypersensitivity)	Severe reaction by the cat to the saliva of the flea	Intense itching, redness, hair loss papules, crusts, and scales; sometimes development of infection or hot spots	Presence of fleas; reaction to intradermal testing	Flea Control in the environment and on the cat; steroids and antihistamines for the itching
Folliculitis	Infection of the hair follicles; symptoms usually appear on face, neck, and head	Pustules develop in the hair follicles and open and form crusts; may itch and develop hair loss	Skin scraping; culture; biopsy; look for underlying condition such as allergy or FIV	Antibiotics, usually for 3-4 weeks; treat any underlying condition
Food allergies	Allergic reaction to something in the diet	Licking of feet, inflamed ears, itching, redness, and hair loss; sometimes development of infection or hot spots	Food elimination trials	Change in diet
Hookworms	Infection with the larvae (immature forms) of hookworms	Red bumps, usually on feet, rough foot pads, abnormal nail growth, itching	Physical exam, history of poor sanitation	Treat for intestinal infection; move cat to different environment
Hot spots (acute moist dermatitis)	Result from allergies, flea bites, mange, anal gland disease, poor grooming, ear infections, plant awns or burs, arthritis	Hair loss; red, moist, oozing skin; constant licking or scratching	Physical exam and history	Treat underlying condition; clean area; apply Domeboro solution; topical and/or oral antibiotics and steroids
Lice	Infection with several species of lice	Variable: itching, hair loss, crusts, rough hair coat	Finding lice or nits on skin or hair	Pyrethrin, ivermectin (off-label use*)
Malassezia	Usually follows some other underlying disease	Itching, redness, hair loss, greasy scales; if chronic, develop hyperpigmentation	Skin scraping/smear and microscopic examination, culture	Treat underlying disease; oral ketoconazole; miconazole shampoos
Miliary dermatitis in cats	Part of the common eosinophilic allergic syndrome in cats which includes eosinophilic granulomas, eosinophilic plaques, and rodent ulcers; may also be associated with infections, autoimmune diseases, hormonal disorders, and nutritional deficiencies	Multiple small crusty bumps, usually over hips, neck, and back of thighs; moderate to severe itching	Microscopic examination of swab from lesion, biopsy, CBC (find increased eosinophils); look for underlying cause, e.g., parasites, food allergy, atopy	Treat underlying cause if found; corticosteroids; fatty acid supplements
Notoedric mange	Infection with the Notoedres mite	Intense itching and self-trauma, skin thickening, gray crusts develop	Skin scraping and microscopic examination	Lime sulfur dips, ivermectin (off-label use*)
Pemphigus foliaceus	The most common form of pemphigus in the cat; an autoimmune disease	Often affects feet and head; starts with pustules and progresses to severe crusting; depigmentation of the nose is common; itching may occur; if footpads and nails affected often see lameness; symptoms wax and wane; severely affected cats may have fever and loss of appetite	History, physical exam, skin scraping and biopsy	Corticosteroids, other immunosuppressive therapy, gold injections
Psychogenic (neurogenic) dermatitis	Self-licking in cats results in self-trauma; possible causes include anxiety, boredom, stress (e.g., new member in household)	Symmetrical hair loss, sometimes ulcers, on abdomen, groin, along the back	Exclude other causes; history important	Relieve underlying cause e.g., anxiety; restrict licking; behavior modifying medication may be necessary
Pyoderma-superficial See Folliculitis
Ringworm	Infection with several types of fungus	Hair loss, scaliness, crusty areas; some itching	Culture	Miconazole, lime sulfur dips; oral griseofulvin or itraconazole; ringworm vaccine
Seborrhea	Can be primary (inherited) or secondary (resulting from other disease processes such as FeLV, FIP, FIV, ringworm, and parasites)	Scales; depending upon the type, may have a dry or oily coat; odor; some scratching; may see hair loss	Blood tests, skin scrapings, etc., to find underlying cause	Treat underlying cause if present; antiseborrheic shampoos; fatty acid supplements
Tick bites	Ticks cause a local inflammation in the skin, even when the entire tick is removed	Nodule and redness at site of the bite; may itch and develop crusts; may last several months	History	Remove the tick; use a tick preventative; allow nodule to resolve on its own
Urticaria (hives)	Reaction, often allergic, to insect bite, drug, vaccine, sunlight, etc.	Multiple swellings, with hair standing up over swellings; may itch	History, physical exam	Often resolves on its own; in the case of allergic reactions, antihistamines, epinephrine or corticosteroids depending upon severity
Xanthoma	Result of abnormality in lipid metabolism; can be a result of diabetes mellitus or due to hereditary affecting lipid metabolism (hyperlipidaemia)	White or yellow nodules, usually on head, extremities, and bony prominences; often painful and itchy	Physical exam and history; biopsy;	Treat underlying disease; change diet; lesions often recur if surgically removed