DEN 2311-Oral Pathology
Actinic keratosis is a term that describes skin lesions with a precancerous tendency that result from chronic and prolonged exposure to the sun. Actinic keratosis usually presents as single or multiple lesions with a sandpaper texture.( References 1,2,5) The lesions are observed as “small, red, scaly patches” which appear on sun-exposed body parts such as the face, ears, scalp, neck and backs of the arms and hands. (Ref 3, 5) Actinic cheilitis is a similar sun exposure associated skin disorder that occurs on lower lip vermilion.( Ref 4)
Actinic keratosis is caused by chronic sun exposure over a long period of time. Activities such as sunbathing and working outdoors increase the risk of acquiring actinic keratosis. Ultraviolet exposure from the sun exerts adverse effects to skin cells by predisposing them to gene mutation and molecular transformations. (Ref 1) The population at higher risk includes individuals with fair skin tone, red or blond hair and blue eyes(“Celtic type skin or Fitzpatrick skin type 1-2”; those who are more prone to sunburn), outdoor workers and regular users of sun beds, and immunosuppressed patients.(Ref 3,5) Actinic keratosis tends to occur in males over the age of 60. (Ref 5)
Actinic keratosis may possess variable clinical appearances. On sun-exposed sites in the body, they usually arise as either individual or a group of roughened spots which may increase in size to 3-10cm in diameter. (Ref 5) They are usually more easily palpated than seen. Lesions may exhibit “rough, elevated, scaly bumps with a sandpaper-like texture”. (Ref 1) According to Goad N. (Ref 2), actinic keratoses do not always appear as red lesions. They can be skin-colored, pink or brown. “They can become raised, hard and warty, and may even develop a small horny outgrowth (due to excessive keratin production). The surrounding skin often looks sun-damaged----blotchy, freckled and wrinkled.”(Ref 2,5)
Due to the pre-malignant nature of actinic keratosis, early detection may be a key to lower the risk of progression to squamous cell carcinoma. Oftentimes, visual inspection plus palpation of the lesions is sufficient for a diagnosis to be made. However, actinic keratosis can be underdiagnosed or misdiagnosed due to a variety of clinical presentations.( Ref 1) Some other possible variations in presentation include “cutaneous horns, hyperkeratosis, and pigmented, lichenoid, verrucous, confluent, and atrophic variants.”(Ref 2). Differential diagnosis of actinic keratosis usually comprises of discoid lupus erythematosus, seborrheic keratosis, basal cell carcinoma, malignant melanoma, verruca vulgaris, squamous cell carcinoma, lichenoid keratosis and other benign inflammatory disorder.(Ref 1) Distinguishing actinic keratosis from these conditions can be challenging. Thus, a biopsy may be indicated for a definitive diagnosis if lesions recur after treatment or when concerns are raised regarding malignant transformation of the lesions.(Ref 1,5) Suspicious signs include bleeding, itching, pronounced hyperkeratosis, erythema, and induration(Ref 1,5). Microscopically, “actinic keratosis is characterized by hyperparakeratosis and acanthosis”. (Ref 4)
Actinic keratoses are usually not harmful and remain undetected in affected individuals. Since small lesions may even go away on their own, no treatment is required if only small lesions are present. Protection from sun exposure by wearing protective clothing and sunscreen should suffice. However, treatment should be sought if lesions exhibit changes in size and texture. (Ref 2) If left untreated, actinic keratosis has a tendency to progress to squamous cell carcinoma.(Ref 1)
Treatment options for actinic keratosis include cryotherapy, surgical removal, application of a cream, and photodynamic therapy. (Ref 2) Treatment approach can be selected based upon the extent of the skin lesion and patient preference. Cryotherapy, the use of liquid nitrogen, is effective when small individual localized lesions are present. Curettage, the surgical removal of abnormal tissues, is effective for highly recurrent lesions and provides a specimen for histologic analysis. When lesions are multiple or involve extensive areas, application of the following topical agents are viable: 5% fluorouracil cream, diclofenac gel, imiquimod 5%, salicylic acid ointment 2% and systemic retinoids. Photodynamic therapy is the application of a chemical followed by irradiation; it is used as an alternative to cryotherapy for more desirable cosmetic results. (Ref 1,2,5)
As dental hygienists, we should become familiar with the clinical presentations and implications of actinic keratosis. Conducting head and neck exam is one of our responsibilities. The capability of recognizing abnormal lesions especially on the head and neck region will enable dental professionals to refer patients for medical guidance promptly. We can also educate the patients about the risk of these premalignant lesions turning into squamous cell carcinoma and suggest patients to use sun screen and physical protections for prevention of excessive sun exposure.
1. Englert, C., & Hughes, B. (2012). A review of actinic keratosis for the nurse practitioner: Diagnosis, treatment, and clinical pearls. Journal Of The American Academy Of Nurse Practitioners, 24(5), 290-296. doi:10.1111/j.1745-7599.2011.00686.x
2. Goad, N. (2009). Recognising potential skin cancer. Practice Nurse, 37(8), 25.
3. Hepplewhite, A. (2012). Management of patients with actinic keratoses. British Journal Of Nursing, S27-30.
4. Neville, B., Damm, D., Allen, C., & Bouquot, J. (2009). Epithelial pathology. In Oral and maxillofacial pathology (3rd ed., pp. 404-406). St. Louis, Mo.: Saunders/Elsevier.
5. Watkins, J. (2014). Actinic (solar) keratoses: investigations and management. British Journal Of Nursing, 23(S4), S43.