Clinical Aspects of Actinic Keratosis

abbreviations: AK=Actinic Keratosis; SCC= Squamous Cell Carcinoma

How to they look like ?
On clinical examination, they present as rough, scaly papules and plaques which are more easily felt than seen
Clinical features of severity can be summarized by the following:
-induration, infllammation
-diameter of 1cm or more
-rapid enlargement
-bleeding and/or erythema
-ulceration

Dermoscopical caracteristic: strawberry pattern+ red pseudo network

Confocal microscopy and optical coherence tomography can help also in the detection of the extent of field cancerization (non visible damage)
The utility multiphoton microscopy is being evaluated.

How are they quantified ?
-There is no consensus in grading systems.
-There is considerable discrepancies of the number of lesions when moving from one dermatologist to the other.
-Moreover, photography is not reliable (Australian study)

Are they frequent ?
–Incidence is increasing
-Australia capital of the world and because of this increasing incidence cost are estimated to reach USD25 million dollars in 2020
–prevalence varies widely and ranges from 1.4% to 58%:

• prevalence in white Australians is the same as Europeans in the 70s
• 10% of older men according to a study in Germans in 90000 employees)
• 37% had at least 1 AK according to a study from the Netherlands in 2000 males clinically examined by dermatologists. 10% had more than 10 Aks.

Who is affected ?
–men are affected more than females
–old age
–fair skin and latitude (indeed as mentioned a study shows that prevalence in white Australians is the same as Europeans in the 70s)
–baldness

When must one be more careful ?
-In immunosuppressed individuals (transplant recipients, HIV) as AKs (also called now onwards as Squamous Cell Carcinoma in situ) can easily progress to SCC.

What happens if an individual AK is not treated ?
-individualy, less than 1% (0.075% will progress per year)
-but this is of course much a higher if there are multiple AKs
–this increases to 0.53% if there was a previous SCC
–a quarter of AKs will regress
(When looking the other way around, 2 thirds of lesions of SCC arise from AK)

The impact of AK on quality of life (QoL)
-AK is a chronic disease
-It has been shown to have a negative impact on QoL
-A questionnaire has been developed in Denmark called AKqol: Its a 9-question questionanire which covers three aspects: function, emotions and control.
Sy52 Update ok AK, BCC and SCC. World Congress of Dermatology 2015 –  Vancouver, Canada