The term keratosis applies to several conditions of the skin which causes bumps, wartlike sores, or flat or raised skin discolorations. Three of the most common types of keratosis are actinic keratosis or solar keratosis, keratosis pilaris, and sebhorreic keratosis. Only actinic keratosis is indicated in the development of skin cancer, as it can cause squamous cell skin cancer. This form of skin cancer should be removed, but does not tend to progress to other parts of the body like malignant melanoma skin cancer.

Actinic keratosis is sometimes called a pre-cancerous condition. It usually presents in people over 30, and is more common among those with fair skin, and those who are outdoors a great deal without using proper sunblocking agents. The growths of this type of keratosis look thick, and may also have a crusty or scaly exterior.

Usually actinic keratosis is diagnosed through examination of the bumps. Sometimes diagnosis is confirmed by taking a skin scraping to rule out squamous cell cancer. Often, large bumps are removed through either laser removal, or cryotherapy, which freezes off the lesions.

People with this form of keratosis do need to follow-up with regular visits to a dermatologist who will watch any bumps not removed for changes indicating squamous cell skin cancer. However, actinic keratosis is removed early enough to not result in any form of cancer, and some spots will never evolve into cancer.

Sebhorreic keratosis is completely benign, and appears as small pink to brown colored warts. Few complications are associated with this form of keratosis, though picking a spot may cause cellulitis. The spots are not usually painful, so pain might be an indication of a different diagnosis or infection. Removal can be undertaken if desired by the patient, but is not necessary, as this form does not progress to cancer.

Keratosis pilaris may appear as red bumps on the skin, rough skin or bumpy skin. It also has no established ties to cancer. It may be misdiagnosed as pimples or as eczema. There is no treatment to cure the condition, which is quite common. However, those with this form may find that exfoliation and moisturizing helps to smooth the skin. Often this type of keratosis occurs in young children and resolves by middle age. Children may scratch the bumps, increasing risk for infection. Otherwise, irritation and complications are uncommon.