Disseminated superficial actinic porokeratosis
DSAP is thought to have autosomal dominant inheritance with onset in the third or fourth decade of life. Women are affected 3 times more frequently than men. Risk factors for developing this disorder also include exposure to ultraviolet radiation and immunosuppression. Individuals with light skin phototypes are more prone to developing this disorder. Recently, mutations in the mevalonate kinase pathway have been identified in DSAP and are thought to be the pathogenetic basis of this disorder.
The potential for transformation to squamous cell carcinoma (SCC) exists but is rare.
L56.5 – Disseminated superficial actinic porokeratosis (DSAP)
41495000 – Disseminated superficial actinic porokeratosis
Differential Diagnosis & Pitfalls
- Actinic keratoses have scale throughout the lesion, whereas in DSAP, scale forms a peripheral thin ridge.
- Granuloma annulare
- Lichen planus
- Seborrheic keratoses have a more "stuck-on" appearance.
- Tinea corporis – A potassium hydroxide (KOH) preparation may be performed to rule out this entity.
- Flat warts