Actinic keratosis (AK) is a common, pre-malignant cutaneous lesion resulting from cumulative, chronic ultraviolet (UV) radiation exposure. These lesions are considered markers of high cumulative sun damage and possess the potential to progress into squamous cell carcinoma (SCC).

AK is primarily caused by prolonged UV exposure leading to DNA damage in keratinocytes. Genetic factors, particularly those affecting DNA repair mechanisms or melanin production, exacerbate risk.

Chronic UV radiation induces mutations in the TP53 tumor suppressor gene. This results in the dysregulated proliferation of atypical keratinocytes within the basal layer of the epidermis, causing abnormal maturation and hyperkeratosis.

Prevalence increases with age; it is most common in individuals over

1. It is significantly more prevalent in fair-skinned (Fitzpatrick types I-II) populations, particularly those living in regions with high solar intensity.

• Chronic UV exposure (sunlight/tanning beds)
• Older age
• Fair complexion
• Male gender
• History of immunosuppression
• Genetic conditions (e.g., Xeroderma pigmentosum)

A. Early Symptoms

• Persistent rough, scaly patches on skin


• Erythematous macules B. Common Symptoms


• "Sandpaper-like" texture


• Tenderness or mild itching


• Persistent scale or crust C. Advanced Symptoms


• Hypertrophic (thickened) growth


• Cutaneous horn formation


• Persistent bleeding or ulceration D. Emergency Symptoms


• Rapid enlargement


• Deep infiltration into underlying tissue


• Bleeding that does not heal

Inspection reveals erythematous, ill-defined papules or plaques with adherent yellow-white scale. Palpation identifies "gritty" texture, often detectable before visible lesions.

A. Clinical Assessment: Visual inspection and palpation.
B. Laboratory Testing: Generally not required.
C. Imaging Studies: Generally not required.
D. Functional Tests: Not applicable.
E. Biopsy Findings: Atypical keratinocytes in the basal layer; hyperkeratosis, parakeratosis.
F. Genetic Testing: Not indicated.
G. Differential Diagnosis: Seborrheic keratosis, SCC in situ (Bowen’s disease), viral warts.

There are no routine blood or urine tests for AK. Diagnosis is primarily clinical or histopathological.