The itchy skin diseases in this table are characterized by constant scratching, licking, and biting at the skin, and rubbing up against objects to relieve the itch. There will be crusty areas produced by scratching.
- Allergic contact dermatitis: Similar to contact dermatitis, but rash may spread beyond the area of contact. Requires repeated or continuous exposure to allergen.
- Chiggers: Itching and severe skin irritation between the toes and around the ears and mouth. Look for barely visible red, yellow, or orange chiggers (the larvae).
- Contact dermatitis: Red, itchy bumps and inflamed skin at the site of contact with a chemical, detergent, paint, or other irritant. Can also be caused by rubber or plastic food dishes. There may be scales and hair loss.
- Ear mites (ododectes): Head tilting and shaking, and scratching at the ears. Excessive brown, waxy, or purulent material in the ear canals.
- Feline miliary dermatitis: Small bumps and crusts around the head, neck, and back felt beneath the haircoat. May be associated with fleas. May be complicated by
- Flea allergy dermatitis: Red, itchy pimplelike bumps over the base of the tail, back of rear legs, and inner thighs. Scratching continues after fleas have been killed.
- Fleas: Itching and scratching along the back, and around the tail and hindquarters. Look for fleas, or black and white gritty specks in hair (flea feces and eggs).
- Food allergy dermatitis: Severe itching over the head, neck, and back. Swelling of eyelids. May only show as reddened ears. Often complicated by hair loss and oozing sores from constant scratching and biting.
- Inhalant allergy (atopic dermatitis): Appearance is similar to feline miliary dermatitis. May have symmetrical hair loss over body.
- Lice: Two-millimeter-long insects, or white grains of sandy material (nits) attached to the hair. Found beneath matted coats in poorly kept cats. May have bare spots where hair has been rubbed off.
- Maggots (myiasis): Soft-bodied, legless fly larvae found in damp matted fur or open wounds. May be complicated by pyoderma.
- Scabies (sarcoptic mange): Intense itching around the head, face, neck, and edges of the ears. Hair is rubbed off. Typical thick gray to yellow crusts. May be complicated by pyoderma.
- Ticks: Large or very small insects attached to the skin, or possibly walking slowly through the hair. May swell up to the size of a pea. Often found around the ears, along the back, and between the toes.
- Walking dandruff (cheyletiella mange): Large amounts of dry, scaly, flaky skin over the neck, back, and sides. Itching may be mild.