Keratosis
Keratosis refers to benign growths of keratin on the skin, with three primary types: actinic keratosis, seborrheic keratosis, and keratosis pilaris. Actinic keratosis is considered a premalignant condition often resulting from excessive sun exposure, presenting as thick, scaly patches on sun-exposed skin. Seborrheic keratosis appears as benign growths that can vary in color and are most common in individuals over forty. Keratosis pilaris, often referred to as "chicken skin," manifests as rough bumps typically on the upper arms, thighs, or other areas, and is more prevalent in adolescents and women. The diagnosis of keratosis usually involves visual examination, while biopsies may be performed for more complex cases. Treatment options vary: actinic keratosis can be treated with cryosurgery or topical agents, while keratosis pilaris may be managed with exfoliating creams. Preventive measures for actinic keratosis include sun protection, aligning with skin cancer prevention strategies. While seborrheic keratosis is generally harmless and may not require treatment, keratosis pilaris does not have a definitive cure, although symptom relief is possible.
Subject Terms
Keratosis
ALSO KNOWN AS: Actinic (solar) keratosis, seborrheic keratosis, keratosis pilaris (chicken skin)
RELATED CONDITIONS: Actinic keratosis, seborrheic keratosis, keratosis pilaris
DEFINITION: Keratosis is a benign growth of keratin on the skin. There are three main kinds of keratosis: actinic keratosis, seborrheic keratosis, and keratosis pilaris.
Risk factors: Risk factors are sun exposure, fair skin, and genetic factors.
Etiology and the disease process: is a premalignant condition of the skin, presenting as thick, scaly, or crusty patches. Frequent sun exposure and fair skin may increase the risk of developing actinic keratosis. A seborrheic keratosis is a benign skin growth on the top layers of the epidermis. It has been associated with a mutation in the growth factor receptor (FGFR3) gene. Keratosis pilaris is a follicular condition that runs in families. It is often worse in winter than in the summer, but it often improves with age. There are several different types of keratosis pilaris, including keratosis pilaris rubra (inflamed and red bumps), alba (bumpy skin without irritation), and rubra faceii (reddish rash on the cheeks).
Incidence: Seborrheic keratosis is most common among people over forty years of age. Keratosis pilaris affects an estimated 50 to 80 percent of adolescents and 30 to 50 percent of the adult population. It is more common in women than in men.
Symptoms: In actinic keratosis, the affected area of the skin may be the same color, darker, or lighter than the skin. It is often accompanied by solar damage in consistently sun-exposed areas. Seborrheic keratosis growths resemble warts and may exhibit a variety of colors, from yellow to black. Keratosis pilaris is excess keratin in the skin that accumulates within the hair follicles. Keratosis pilaris appears as rough bumps on the skin, most often on the backs and outer sides of the upper arms. It may also appear on the lower arms, thighs, or any body part except on glabrous (hairless) skin.
Screening and diagnosis: People with mild keratosis pilaris often are not aware of the condition. Diagnosis is generally made by visually examining the skin. Skin biopsies are sometimes done in seborrheic and actinic keratosis.
Treatment and therapy: Actinic keratosis is often treated with cryosurgery. Other therapies involve the application of 5-fluorouracil, a agent, photodynamic therapy, electrocautery (burning off the area with electricity), and topical immunotherapy. Keratosis pilaris can be treated with creams containing alpha hydroxy acid, lactic acid, salicylic acid, and topical retinoids. The FDA approved a new topical microtubule inhibitor for actinic keratosis and laser-assisted photodynamic therapy has also been effective in treating actinic keratosis lesions.
Prognosis, prevention, and outcomes: Preventive measures for actinic keratosis are similar to those for skin cancer, such as limiting sun exposure and applying sunscreens. Because seborrheic keratosis tumors are a benign and not painful condition, treatment is often not necessary. There is no cure for keratosis pilaris, but there are treatments to alleviate symptoms.
"Keratosis Pilaris - Diagnosis and Treatment.” Mayo Clinic, 17 Feb. 2024, www.mayoclinic.org/diseases-conditions/keratosis-pilaris/diagnosis-treatment/drc-20351152. Accessed 14 June 2024.
Lehrer, Michael. “Seborrheic Keratosis.” Cedars-Sinai, www.cedars-sinai.org/health-library/diseases-and-conditions/s/seborrheic-keratosis.html. Accessed 14 June 2024.
Pennycook, Keith. “Keratosis Pilaris - StatPearls.” NCBI, 26 June 2023, www.ncbi.nlm.nih.gov/books/NBK546708/. Accessed 14 June 2024.