Solar Keratoses

Question 1

Prevalence

Answer 1

40-50% of population over 40yrs old.

Question 2

Aetiology

Answer 2

Related to sun exposure. Risk for skin cancer.

Predisposed if fair skin that burns, history of skin cancer, immunosuppression.

Question 3

Pathogenesis

Answer 3

UV radiation damages skin cells which can lead to mutations, activation of oncogenes/inactivation of tumor suppression genes therefore tumour initiation and progression.

Question 4

Signs

Answer 4

Onset slow, enlarge over time. Asymptomatic- no itch or pain.
Found on sun-exposed areas like back of hands, forearms, face and scalp.
Scaling lesion. Erythematous, slightly inflamed at the base. Fade into surrounding skin, no clear border. 2-20mm in diameter can be pigmented.
May be difficult to distinguish from superficial BBCs.

Question 5

Treatment

Answer 5

Need to be treated due may develop into cancer.
May clear spontaneously as new lesions appear elsewhere.
Minor-Salicylic acid 2-5% crm or ointment 1-2 daily.
Multiple lesions- Diclofenac gel 3% bd 12/52 OR fluorouracil 5% crm 1-2x daily for 2-6/52 OR imiquimod 5% crm 3x/week 3-4/52.
Worse before it gets better.
Photosensitivity, inflammation, redness, burning, itch.

Question 6

Symptoms

Answer 6

Asymptomatic but will sting if picked.

Tenderness, increasing thickness means may be squamous cell carcinoma.