A guide to ear margin hyperkeratosis

Ear margin hyperkeratosis goes by several names, including ear margin dermatosis (EMD) and ear margin seborrhea Trusted Source The Merck Veterinary Manual Trusted provider of veterinary medicine. Go to source . This skin condition is typically limited to the outer edges of the pinna, which is the flap portion of your pooch’s ear. If your pup has ear margin hyperkeratosis, it may look like they’ve got crusty ears. Waxy, yellow, or gray lesions also form on the tips of the ears and can look and feel like thickened skin. Hyperkeratosis of the ears is less common than other keratinization disorders, like nasal hyperkeratosis and paw pad hyperkeratosis

Ear margin hyperkeratosis generally appears as waxy, scaly gray or yellow skin. The scaly skin sticks to the base of the hair shafts along the margins of your dog’s ears. Plugs of hair can easily be pulled out, leaving behind skin with a shiny surface. Severe cases cause the edges of the ears to swell and crack. Both ears are commonly affected, and the condition can spread from the tips of the ears to cover the entire pinna.

Although this condition can look uncomfortable, it usually doesn’t itch or hurt your dog. They may shake their head, though, especially if their ears become swollen and heavy.

The crusty appearance of your pup’s ears may not have an identifiable cause. In most cases, ear margin hyperkeratosis is idiopathic, meaning the exact cause isn’t known. However, it’s thought that this condition is caused by a genetic abnormality of keratinization. This is because dachshunds seem to be most commonly affected, potentially because of a genetic defect.

Sometimes, though, ear margin seborrhea is caused by an underlying medical problem. Ear margin hyperkeratosis may appear as a side effect of the following issues:

• Hormonal imbalances. Hyperkeratosis can appear on the ears of dogs with hypothyroidism. Occasionally, dogs with Cushing’s disease can also be affected.
• Allergies. Allergies are notorious for causing skin issues in dogs, particularly hair loss and scaly skin.
• Parasites. Fleas, ticks, flies, and mites can cause areas of hair loss and crusty skin in dogs.
• Yeast infections. Malassezia yeast can trigger a case of ear edge seborrhea, particularly in Yorkies and dachshunds.
• Poor diet. A poor diet, particularly one lacking in adequate essential fatty acids, can cause coat and skin problems.
• Environmental factors. It’s thought that ear margin hyperkeratosis can worsen with dry heat and low humidity, since environmental factors such as these can damage your pup’s skin barrier.
• Obesity. Weight gain goes paw-in-paw with hypothyroidism, so if your pup is packing on the pounds and suffering from hyperkeratosis, they may have an endocrine disorder.

Other causes of crusty ears in dogs

Your vet will need to rule out other potential causes of your pup’s crusty ears to provide the proper treatment. Conditions that appear similar to ear margin hyperkeratosis include:

• Ear edge vasculitis. In this condition, “punched out” lesions can appear in the pinna, resulting in alopecia and/or necrosis of the ear edges.
• Sarcoptic mange. Sarcoptic mange mites can create keratinous crusts along the ear margins. Unlike hyperkeratosis, this form of mange causes pruritus, or severe itching.
• Pinnal alopecia. Hair loss, or alopecia, on the ear flaps can occur without cause, but it appears to be genetic.
• Proliferative thrombovascular necrosis. Although this condition is rare, it can appear as scaly, thickened, hyperpigmented skin surrounding a necrotic ulcer.
• Dermatophytosis. Ringworm is a fungal infection that can cause pinnal dermatitis, giving a pup’s ears a scaly appearance.
• Frostbite. Frostbite typically affects the tips of the ears, causing crusting, ulceration, and necrosis.

Ear margin hyperkeratosis is most likely to affect dogs with long-hanging ears, although it can occur in other types. Breeds most commonly affected include:

• Dachshunds
• Cocker spaniels
• Springer spaniels
• Great Danes
• Basset hounds
• Yorkshire terriers
• Chihuahuas

To rule out other causes of crusty ears in your pup, your vet will likely recommend a series of diagnostic tests. Similar conditions can be eliminated from the differential diagnoses list by performing the following tests:

• Skin cytology. A skin cytology will determine if inflammatory cells, yeast, or bacteria are present.
• Skin biopsy. A skin biopsy is necessary to differentiate between keratinization abnormalities and more severe pinnal diseases.
• Skin scraping. A skin scraping test checks your dog for the presence of mange mites.
• Blood work. General blood work, like a CBC and chemistry panel, may be recommended, along with blood tests to check for hormonal imbalances.
• Fungal culture. A few strands of your dog’s fur can determine if their ear crusting is caused by ringworm.

If your pup’s crusty ears are caused by an underlying condition, your vet will administer the proper treatment to clear up the primary cause. Their ear issue should then resolve.

If no underlying condition is found, your dog’s ear margin hyperkeratosis can’t be cured. In these cases, management is the goal. However, yeast and bacterial infections (like staph) are common and can complicate management.

In general, ear margin hyperkeratosis is a stable or slowly progressive condition that typically does not cause dogs pain. Severe hyperkeratosis can be problematic, though, and may require advanced treatment, like surgery.

Methods for management

Dogs with ear margin hyperkeratosis generally respond well to medicated shampoos, although other treatments can also help. Your vet may recommend the following management tools:

• Antiseborrheic shampoos and sprays (e.g., sulfur, salicylic acid, benzoyl peroxide)
• Keratolytic products (e.g., salicylic acid gel, topical moisturizers)
• Retinoids containing vitamin A
• Oral cyclosporine
• Topical or oral corticosteroids
• Pentoxifylline for severe inflammation
• Omega-3 fatty acid supplements

Antibiotics may also be necessary to treat secondary bacterial infections.

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Although you may not be able to completely prevent ear margin hyperkeratosis in your dachshund, you may be able to keep it at bay. Try the following tips for prevention:

Keep up with monthly flea treatments — Flea and tick treatments can also protect your pup from mange mites and other biting insects that can damage their ears.

Clean your pup’s ears regularly — Cleaning your dog’s ears regularly — but no more than two or three times a week — allows you to keep an eye on them for changes. It also removes keratin debris, wax, and other buildup from the ear canals that can lead to issues.

Ensure your pup has a healthy, balanced diet — Secondary seborrhea can be caused by obesity, so stick to a healthy diet for your pooch.

Protect your dog’s ears from the weather — When outside with your pup, avoid excessive exposure to harsh elements, like the sun or cold. The fragile skin on your dog’s ears can be easily damaged by extreme conditions.