Actinic keratosis
- Synonyms
Solar Keratoses
- ICD 10
Diagnosis Code L57.0
Definition
A skin condition characterized by lesions on the skin. The condition occurs if a person is exposed to the sun for a long time.
Epidemiology
Actinic keratosis occurs worldwide with continuous prevalence with every dawn. It is estimated that more than 40 million Americans develop actinic keratoses (AKs) each year. Anyone can develop the condition, but mostly, it affects immune-compromised patients and fair-skinned patients who have been exposed to the sun for a long time. The high-risk groups include people who spend their recreational time outdoors or persons who use tanning beds. It is also prevalent among outdoor workers. The amount of solar ultraviolet radiation exposure also increases a person’s risk of developing the condition.
The highest rates are reported in countries where fair-skinned people are close to the equator. In the northern latitudes, like in the U.K., a quarter of individuals above 60 years have one person with actinic keratoses. In Australia, 55% of men between the ages of 30 and 70 suffer from the condition. In the U.S., the prevalence rates are between 11-26%. Don't use plagiarised sources.Get your custom essay just from $11/page
Due to the risk of AK progressing to Squamous Cell Carcinoma (SCC) and the failure of diagnostic techniques, the trend of the lesions, management guidelines recommend that all patients with the condition are treated as soon as they are detected.
Pathophysiology/Etiology
Actinic keratoses affects fair-skinned people around regions of their skin that have been affected by continuous sun exposure like the face, bald scalp, ears, back of the hands, and forearms. It can also occur in other areas that been exposed to the sun like the chest, back, and legs. The frequency of actinic keratosis is associated with cumulative UV exposure. Thus, the rate of AK increases with every decade of life and mainly affects people who live in sunny countries that are near the equator and also in persons with outdoor occupations. An analysis of DNA containing cells with actinic keratoses reveals UV-induced mutations in genes such as the TP53 and the destruction of the gene coding the p16 tumor suppressor protein.
In the long term, actinic keratoses progress into squamous cell carcinoma. In one study, almost 7,000 patients, it was found that AK takes two years to progress into squamous cell carcinoma. Development of the condition occurs as early as 30 to 40 years for people who live in regions with high solar radiation, do not use sunscreen protection, and are fair-skinned.
In terms of molecular and histologic parameters, actinic keratoses have the same features as squamous cell carcinoma. AK is characterized by aggregates of pleomorphic keratinocytes at the basal layer that could extend to affect the cornified and granular layers.
Clinical History
It would help if you asked the patient when they first noted they had the condition. Actinic keratoses that occurred from birth could mean it is genetic. However, it would help if you also inquired about a patient’s UV exposure and their occupation. Additionally, determine whether the patient has gone through any procedures that could suppress their immune system, such as organ transplantation.
Differential DX
When diagnosing actinic keratosis, you have to differentiate the symptoms from those exhibited in conditions such as:
- Discoid Lupus Erythematosus: Characterized by dilated follicles, dyspigmentation, and atrophy
- Bowen Disease: Characterized by a large plaque
- Seborrheic Keratosis: Characterized by greasy brown crusts that occur in exposed regions
- Basal Cell Carcinoma: Characterized by an epithelial tumor or small round cells found in the lower part of the epidermis
Lesions characterized by persistent itching, bleeding, and growth, can be biopsied to make an accurate diagnosis.
Examination
To identify the presence of actinic keratosis, the doctor will use a slit lamp, a dermatoscopy, or even observe the patient with their naked eye. The doctor will be looking for signs such as erythematous, scaly macule, and papule on the skin surface. Some of the symptoms the doctor will be expecting are rough skin and lesion with a scaly appearance. Irritation or itching on the skin of the patient is also a common symptom.
Work Up
When physical exams are not enough, histopathology will be performed on biopsies.
Treatment
The most common treatment is surgical destruction of the lesion with observation and medical treatment, since this is a benign condition. Medical treatment will be chosen depending on the number of lesions. Some other variables that need to be considered include the patient’s age, history of skin cancer, and tolerability of the treatment. The patient will be instructed on how to limit sun exposure and to wear sunscreens and protective clothing.
The medications that have been approved by the FDA for treating actinic keratoses include topical diclofenac gel, PDT with topical delta-aminolevulinic acid, ingenol mebutate, 3.75% imiquimod cream, and 5-fluorouracil (5-FU). 5-FU is famous for treating actinic keratoses by inhibiting thymidylate synthetase and causing cell death in proliferating cells.
Other conventional treatments include:
- Laser resurfacing
- Curettage
- Photodynamic therapy
- Chemical peel
Follow up (F/u)
Patients are advised to avoid exposure to the sun between 10:00 am and 3:00 pm as much as possible. They are also encouraged to wear sunscreen and protective clothing.
Research
References
Frost CA, Green AC, Williams GM. The prevalence and determinants of solar keratoses at subtropical latitude (Queensland, Australia). Br J Dermatol. 1998 Dec. 139(6):1033-9.
Grossman D, Leffell DJ. The molecular basis of nonmelanoma skin cancer: New understanding. Arch Dermatol 1997; 133(10):1263-70.
Quatresooz P, Piérard-Franchimont C, Paquet P, Hubert P, Delvenne P, Piérard GE. Crossroads between actinic keratosis and squamous cell carcinoma, and novel pharmacological issues. Eur J Dermatol 2008; 18(1):6–10.
Roewert-Huber J, Stockfleth E, Kerl H. Pathology and pathobiology of actinic (solar) keratosis – an update. Br J Dermatol. 2007 Dec. 157 Suppl 2:18-20.
Links
https://emedicine.medscape.com/article/1099775-overview#a9
https://eyewiki.aao.org/Actinic_keratosis
https://www.aad.org/public/diseases/skin-cancer/actinic-keratosis-overview
https://www.icd10data.com/ICD10CM/Codes/L00-L99/L55-L59/L57-/L57.0