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Sterile Nodular/Granulomatous Dermatoses in Dogs

Sterile nodular/granulomatous dermatoses are diseases in which the primary lesions are nodules, or masses of tissue that are solid, elevated, and greater than one centimeter in diameter.

The nodules are usually the result of an infiltration of inflammatory cells into the skin.  This may be a reaction to interal or external stimuli. 

Symptoms and Types

• Nodular dermatofibrosis in German shepherds, 3–5 years old
• Calcinosis circumscripta in German shepherds, younger than two-years-old
• Malignant histiocytosis in Bernese mountain dogs
• May affect any age, breed, or gender, although Bernese mountain dogs are at higher risk for malignant histiocytosis and German shepherds are at higher risk for nodular dermatofibrosis

Causes

• Amyloidosis - a waxy protein deposit, or amyloid, in the body
• Reaction to foreign body
• Spherulocytosis - disease of red blood cells
• Idiopathic sterile granuloma and pyogranuloma
• Canine eosinophilic granuloma - eosinophils from blood infiltrates the skin
• Calcinosis cutis - skin disease accompanying Cushing’s disease in dogs
• Calcinosis circumscripta - skin stones, similar to calcinosis cutis
• Malignant histiocytosis - abnormally spreading immune-type cells
• Cutaneous histiocytosis - immune-type cells spreading to skin
• Sterile panniculitis - inflammation of the skin
• Nodular dermatofibrosis - bumps filled with excess elastic skin material which accompanies kidney disease
• Cutaneous xanthoma - a benign skin problem, involving immune cell infiltration usually accompanies hyperlipoproteinemia or diabetes mellitus

Diagnosis

Your veterinarian will perform a thorough physical exam on your dog, with a blood chemical profile, a complete blood count, an electrolyte panel and a urinalysis. You will need to provide a thorough history of your dog's health leading up to the onset of symptoms.

The physical exam should include a dermatologic exam, during which skin biopsies for histopathology can be taken to determine if structural changes have occurred in the tissue.  Skin scrapings will also be examined microscopically and cultured for bacteria, mycobacteria and fungi.