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Dermatoses, Depigmenting Disorders

Skin dermatoses is a general medical term that applies to several types of bacterial infections or genetic diseases of the skin. Some dermatoses are cosmetic conditions involving loss of pigmentation of the skin and/or hair coat, but are otherwise no harmful.

For instance, German Shepherds tend to bacterial skin infections involving areas of the lips, eyelids, and nostrils. German Shepherds, Collies, and Shetland sheepdogs are predisposed to lupus, an autoimmune disease in which the body attacks its own skin and other organs, and discoid lupus, an autoimmune disease involving the skin only, usually the face.

Chow chows and Akitas are predisposed to an autoimmune disease involving the skin, characterized by inflammation with crusting, and lesions containing pus.

Akitas, Samoyeds and Siberian huskies tend to develop a rare syndrome that causes inflammation in the front part of the eye. The most affected area is the iris, with coexistent inflammation of the skin characterized by loss of pigment in the skin of the nose and lips.

Doberman Pinschers and Rottweilers may develop a condition characterized by symmetrical lack of pigment in the skin and a white hair coat, especially involving the face and nose. Siberian Huskies, Alaskan Malamutes, and Labrador Retrievers can display a seasonal loss of pigment in the tough, hairless skin of the nose. St. Bernards and Giant schnauzers can be afflicted with inflammation of the arteries of the nasal philtrum, the juncture between the sides of the upper lip extending to the nose.

Symptoms and Types

• White hair (known as leukotrichia)
• Partial or total lack of pigment in the skin (known as leukoderma)
• Reddening of the skin (known as erythema)
• Loss of the top surface of the skin (known as an erosion or ulceration, based on depth of tissue loss)

Causes

• Bacterial skin infections; the most commonly affected areas are:
  • Lips
  • Eyelids
  • Nostrils
• Fungal infection of skin
• Contact hypersensitivity (allergies)
• Skin on face tends to be primarily affected
• Red skin and pus - face and ears
• Crusting scabs and pus on skin
• Loss of skin/hair color after skin was inflamed
• Loss of color on nose and lips, vision loss
• Seasonal nasal depigmentation
• Inflammation of the arteries of the nasal philtrum (very front of nose, above upper lip)
• Albinism (genetic)
• Vitiligo (smooth white patches of skin due to loss of skin color)
• Severe: skin and bodily organs affected
• Autoimmune disease (often there is a genetic predisposition)
• Systemic lupus erythematosus
• Discoid lupus erythematosus
• Pemphigus foliaceus
• Pemphigus erythematosus
• Uveodermatologic syndrome
• Hormonal disorders
• Drug reaction

Diagnosis

Your veterinarian will perform a thorough physical exam on your dog, taking into account the background history of symptoms and possible incidents that might have precipitated this condition, such as whether your dog suffered a recent infection. You will need to give a thorough history of your dog's health and onset of symptoms. Your veterinarian will order a blood chemical profile, a complete blood count, an electrolyte panel and a urinalysis. Blood samples can be tested for autoimmune factors.

As part of your dog's physical exam, your veterinarian will take skin samples and skin scrapings to send to a lab for bacterial and fungal cultures. If the skin biopsy shows that skin cells are separating from each other (acantholytic), this is diagnostic for pemphigus. Direct immunofluorescence of skin samples using fluorescent dyes can also be used to demonstrate antibodies. Your veterinarian may also take fluid samples from your dog's joints to check for lupus.