Papulonodular Dermatoses in Dogs

Papulonodular dermatoses are part of a group of skin conditions that cause small, hard bumps called papules and nodules. They can cause severe itching, which in turn can lead to other serious side effects. There are many causes of papulonodular dermatoses, so treating these conditions can be tricky. You first must discover the underlying cause before you can effectively treat it.

The papules and nodules that this condition causes on the surface of your dog's skin are solid bumps that do not contain liquid or pus. Papules are less than 1 centimeter in diameter and occur when inflammatory cells penetrate your dog's skin. Nodules are larger than 1 centimeter in diameter and extend further down into the tissues. Nodules are caused by a massive infiltration of inflammatory or cancerous cells. The skin lesions can be localized or general and are often accompanied by hair loss, a red itchy rash and crusty patches in the affected area.

Your pup's papulonodular dermatosis can be caused by allergies or a reaction to sunlight. It can also be the result of a bacterial or fungal infection of his hair follicles or an inflammation of the oil glands in his skin. Other causes include ringworm, mange, roundworm infection and cancer. The bumps also may be the result of white blood cells infiltrating the area to fight bacteria.

Your veterinarian will need an update on your furry friend's health history. Did you change his diet or leave him in the sun for an extended period before the onset of the papules and nodules? Did he have a recent bout of internal or external parasite infestations?

To further attempt to determine the condition's cause, your vet will likely do a skin scraping to test for bacteria, fungus or parasites, which may be causing the skin to erupt. Additional tests she may perform include a complete blood profile, a blood chemistry analysis, a complete blood count and urinalysis.

Once the doctor has determined the underlying cause of your pet's dermatosis, she can start the proper course of treatment. If the root cause is bacterial or fungal, she will likely prescribe oral or topical antibiotics or antifungal medications. Bathing with a parasiticidal dip or a dose of dewormer will help get rid of external and internal parasites. Or if the eruptions are caused by sunlight, limit your pup's time outside, especially between 10 a.m. and 4 p.m., and apply sunscreen with SPF rating of at least 15 every 12 hours. You can treat inflammation of the skin's oil glands with a 50 percent solution of propylene glycol and water sprayed on the affected area daily.

In cases in which the root cause is skin cancer, typically squamous cell carcinoma, your doctor will probably recommend several options. Surgical removal of the cancerous tissue along with other therapies may be necessary. However, the long-term prognosis for this type of cancer, unfortunately, is generally not good.