Miliary Dermatitis is a symptom rather than a disease. The condition appears as hair loss around numerous small crusty pustules on an itchy cat. It most often occurs on the neck, back, and rump. Allergies, and specifically flea allergies, are the most common cause of miliary dermatitis. Other causes include bacterial or fungal infections, parasitic infestations, nutritional imbalances and immune-mediated diseases.
Scratching and over-grooming because of an underlying skin condition is what leads to the hair loss and bumps associated with miliary dermatitis. Fleas must be completely ruled out as a contributing factor and can be difficult to find on a cat. Being meticulous groomers with rake-like tongues, cats may ingest many of the fleas that infest them. Flea preventives should always be started in the case of miliary dermatitis, because symptomatic cats are very likely to be allergic to flea bites.
Bacterial and fungal infections may also cause miliary dermatitis. Ringworm is a fungus that causes itching and broken hair shafts. A culture may be performed to diagnose these dermatophytes. Bacterial infection is likely to be secondary to skin disease, or may become established if the immune system is suppressed by viral infection or steroid use. Antibiotics and antifungal drugs may be prescribed in these situations. Antiseptic / antipruritic (anti-itch) shampoos may be useful as well to reduce symptoms and provide relief.
Mange mites are uncommon in house cats, but can cause severe itching and secondary miliary dermatitis. A skin scraping is used to rule out mites as a cause of symptoms.
The treatment for miliary dermatitis begins with eliminating any underlying cause. Oral antihistamines and steroids, in combination with topical products, are used to control itch. An Elizabethan collar can be used to prevent further self trauma.