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Medically reviewed by Last updated on Dec 4, 2023.

What is Hyperkeratosis?

Harvard Health Publishing

Hyperkeratosis is a thickening of the outer layer of the skin. This outer layer contains a tough, protective protein called keratin.

This skin thickening is often part of the skin's normal protection against rubbing, pressure and other forms of local irritation. It causes calluses and corns on hands and feet. It can cause whitish areas inside the mouth.

Other forms of hyperkeratosis can occur as part of the skin's defense against:

Less often, hyperkeratosis develops on skin that has not been irritated. These types of hyperkeratosis may be part of an inherited condition. They may begin soon after birth and can affect skin on large areas of the body.

There are many examples of hyperkeratosis. They include:


Many forms of hyperkeratosis are painless. However, corns, calluses and plantar warts can cause a great deal of discomfort.


Depending on your specific pattern of skin symptoms, your doctor will ask whether you:

Sometimes, your doctor can diagnose the cause of your hyperkeratosis based on your history and symptoms and by examining your skin. This often is the case with corns, calluses, warts and chronic eczema.

If you have chronic eczema that could be allergy-related, the doctor may suggest allergy testing.

In some cases, a biopsy may be taken to confirm the diagnosis. In a biopsy, a small piece of tissue is removed to be examined in a laboratory. If your doctor suspects actinic keratoses, you may need to have a skin biopsy to confirm the diagnosis and to rule out skin cancer.

If your child develops many areas of hyperkeratosis, your doctor may review your family history and skin symptoms. This will help to determine if your child has an inherited disorder.

Expected duration

How long a particular form of hyperkeratosis lasts depends on its cause. For example, corns and calluses usually last as long as a person continues to wear poorly fitting shoes. Warts may disappear on their own. But this may take several months.

Once they develop, actinic keratoses or seborrheic keratoses are long-term conditions. They do not disappear without treatment.

Inherited forms of hyperkeratosis are lifelong conditions.


Some forms of hyperkeratosis are very easy to prevent:

Also, try using blankets and clothing made of cotton. Fabrics such as wool, silk and rough synthetics can be more irritating. Avoiding or removing triggers for your allergies also may help.

Get advice and treatment for mild eczema to help prevent it from becoming a long-lasting condition (chronic eczema).


The treatment of hyperkeratosis depends on the type and possible cause.

Don't shave away or cut a corn or callus on your own. Consult a health professional for advice and treatment.

If the treatment does not reach the layer of skin infected with the virus, the wart can come back in the same place. Repeat treatments may be necessary.

Warts can be treated at home with nonprescription remedies. Self-treatment will take longer for the wart to go away compared to treatment in a medical setting. Self-treatment may be more effective after you have been treated by a health care professional. This is especially true if a wart appears to be large or deep. If you have diabetes or poor circulation, it's best to be treated by a health care professional.

When to call a professional

Make an appointment to see a health care professional or podiatrist if:

People with diabetes should have their feet examined regularly by a health professional to avoid skin infections from corns, calluses or warts.

Adults should examine their skin regularly after age 20. This is particularly true for those who have a history of working or playing for long hours in the sun. If you are not sure how to examine your skin, ask your doctor for guidance.

If you think you have hyperkeratosis or eczema, schedule an appointment with a health care professional.

Whenever you notice that a skin growth or mole has changed color, size or shape, call your doctor for a more urgent appointment. Any new mole or other growth should be checked for signs of cancer.

If you have actinic keratoses, call your doctor for treatment.


Most forms of hyperkeratosis are local skin problems that have a good prognosis.

Actinic keratoses can develop into squamous cell skin cancer.

Additional info

American Academy of Dermatology

American Podiatric Medical Association (APMA)

National Cancer Institute (NCI)

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.