Pre-Malignant Skin Conditions: Actinic Keratosis (Solar Keratosis)

Question 1

Actinic Keratosis (Solar Keratosis)
Lesion

Answer 1

ill-defined, scaly, erythematous papules or plaques on a background of sun-damaged skin (solar
heliosis)

Question 2

Actinic Keratosis (Solar Keratosis)
Palpation

Answer 2

sandpaper-like, gritty sensation felt on palpation, often easier to appreciate on palpation rather than
inspection

Question 3

Actinic Keratosis (Solar Keratosis) sites

Answer 3

areas of sun exposure (face, ears, scalp if bald, neck, sun-exposed limbs)

Question 4

Actinic Keratosis (Solar Keratosis) Pathophysiology

Answer 4

UV radiation damage to keratinocytes from repeated sun exposure (especially UVB)
UV-induced p53 gene mutation

Question 5

Actinic Keratosis (Solar Keratosis)
risk factors

Answer 5

increased age, light skin/eyes/hair, immunosuppression, syndromes such as albinism or
xeroderma pigmenotsum

Question 6

Actinic Keratosis (Solar Keratosis)
risk factors for malignancy

Answer 6

immunosuppression, history of skin cancer,

risk of transformation of AK to SCC (~1/1000), but higher likelihood if AK is persistent

Question 7

Actinic Keratosis (Solar
Keratosis)
Epidemiology

Answer 7

common with increasing age, outdoor occupation, M>F

• skin phototypes I-III, rare in darker skin as melanin is protective

Question 8

Actinic Keratosis (Solar Keratosis)
Differential Diagnosis

Answer 8

SCC in situ, superficial BCC, seborrheic keratosis, cutaneous lupus erythematosus

Question 9

Actinic Keratosis (Solar Keratosis)
Investigations

Answer 9

biopsy lesions that are refractory to treatment

Question 10

Actinic Keratosis (Solar Keratosis)
Management
• destructive:

Answer 10

cryotherapy, electrodessication, and curettage

Question 11

Actinic Keratosis (Solar Keratosis)
topical pharmacotherapy

Answer 11

mechanism: destruction of rapidly growing cells or immune system
modulation)
topical 5-fluorouracil cream (for 2-4 wk), imiquimod 5% (2x/wk for 16 wk), imiquimod 3.75%
(daily for 2 wk then none for 2 wk then daily for 2 wk), ingenol Mmbutate gel 0.015% (daily for 3 d
on the head and neck), ingenol mebutate 0.05% gel (daily for 2 d on the body)

Question 12

Actinic Keratosis (Solar Keratosis) Management. alternative procedures

Answer 12

photodynamic therapy

• excision