Papulosquamous (Psoriasis, Lichen)
Porokeratosis
WHAT IS IT
A scaly patch with a distinctive raised rim
HOW COMMON
Uncommon; a few different types exist
CONTAGIOUS?
No — you cannot catch it or spread it
CURABLE?
Manageable; monitored over the long term
What Is It?
Porokeratosis is a skin condition that causes one or more scaly patches with a distinctive thin, raised ridge around the edge. The most common type appears as many small patches on sun-exposed limbs. It is usually harmless but is monitored because, rarely, a lesion can develop skin cancer over time.
Signs & Symptoms
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Scaly patches with a raised, thread-like border
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A central area that may be dry, thin, or slightly sunken
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Often multiple small patches on the arms and legs
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Usually mild or no itch
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More noticeable on sun-exposed skin
Why Does It Happen?
Porokeratosis is caused by abnormal growth of skin cells in a defined area, producing the characteristic ridged border. Sun (UV) exposure, genetics, and a weakened immune system can all contribute. Some types are inherited. It is NOT an infection and NOT contagious.
Treatment Options
Treatment can improve appearance and symptoms, though patches often persist. Because of a small long-term cancer risk, lesions are monitored and changes are checked.
SUN PROTECTION
Daily sunscreen and cover-up help limit new and worsening lesions.
TOPICAL TREATMENTS
Retinoids, 5-fluorouracil, or other creams for symptoms and appearance.
CRYOTHERAPY / PROCEDURES
Freezing, laser, or removal for individual bothersome lesions.
MONITORING
Watching lesions over time; changing spots are biopsied.
Tips for Managing It at Home
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Use daily broad-spectrum sunscreen and protective clothing
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Do regular self-checks and note any changing or growing patch
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Moisturize dry, scaly areas for comfort
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Keep follow-up visits so lesions can be monitored
When to Call Your Provider
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A patch grows, thickens, bleeds, or forms a sore
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A lesion looks different from the others or changes over time
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New patches appear rapidly
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You have a weakened immune system and notice changes
Sources & further reading
The information in this handout is based on general dermatology guidance from the reputable organizations below. These links are provided for patients who wish to read more from trusted sources.
DermNet. Porokeratosis. https://dermnetnz.org/topics/porokeratosis
MSD/Merck Manual. Porokeratosis. https://www.msdmanuals.com/professional/dermatologic-disorders/psoriasis-and-scaling-diseases/porokeratosis
Cleveland Clinic. Porokeratosis. https://my.clevelandclinic.org/health/diseases/porokeratosis
This handout is for general education and does not replace advice from your own provider. Always follow your provider’s specific instructions.
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