Porokeratosis vs Actinic Keratosis
How to tell the difference — key features compared side by side.
Feature
Porokeratosis
Actinic Keratosis
Category
Pre-cancerous
Pre-cancerous
Key feature
Ring-like lesions with a distinctive raised ridge border. 7-11% lifetime SCC risk.
Rough, sandpaper-like patches from years of sun damage. The most common precancer - 5-10% progress to squamous cell carcinoma.
Risk factors
Genetic predisposition; Immunosuppression; Chronic sun exposure (DSAP variant)
Cumulative lifetime sun exposure; Fair skin, light hair, light eyes (Fitzpatrick I-III); Age over 40
Action needed
Ring-like skin lesions with a raised border
Any rough scaly patch on sun-exposed skin persisting more than two weeks
Porokeratosis
Porokeratosis is characterized by well-defined patches surrounded by a distinctive thin raised ridge (cornoid lamella) - a column of abnormal keratin.
Read full guide →Actinic Keratosis
Actinic keratosis (AK) is the most common precancerous skin lesion, affecting an estimated 58 million Americans. It develops from cumulative ultraviolet radiation damage and represents the earliest stage toward squamous cell carcinoma.
Read full guide →Does yours look more like porokeratosis?
Quick self-check
Does this look like porokeratosis? Answer 2 questions.
Does the lesion have a ring shape with a thin raised ridge border?
Has it been present for months to years?
Still not sure?
Our full ABCDE checker evaluates 5 clinical criteria dermatologists use.
Full ABCDE check →