Author. Dr Karen Koch, Dermatologist, WITS Donald Gordon Mediclinic, Johannesburg, South Africa. DermNet NZ Editor in Chief: Adjunct A/Prof Amanda Oakley, Dermatologist, Hamilton, New Zealand. July 2018.
Porokeratosis is an uncommon skin condition of abnormal keratinisation .
Porokeratosis plantaris, palmaris et disseminata (PPPD) is an extremely rare form of porokeratosis in which scaly red-brown annular patches arise on the palms and soles and spread to the extremities and trunk .
The onset of PPPD is usually during the teenage years. There are rare reports of the onset of PPPD later in life . PPPD was originally reported to be twice as common in men than women .
PPPD generally worsens during summer .
Most often, PPPD occurs as a genetic autosomal dominant condition that runs in families . However sporadic cases may arise .
PPPD usually presents initially as red-brown annular patches on the palms of the hands and soles of the feet. These spread to the extremities and trunk  forming reddish and slightly thinned small patches with defined borders .
PPPD is chronic and progressive and can affect the quality of life.
There is a small risk of progression to cutaneous squamous cell carcinoma in long-standing cases .
The differential diagnosis of PPPD is mainly other forms of porokeratosis, especially DSAP. DSAP has similar skin lesions on the limbs, but they are uncommon on the trunk, and usually, the hands and feet are spared. DSAP tends to affect sun-exposed areas whereas PPPD can affect any part of the body.
Topical treatments may include:
Physical destructive treatments may include:
PPPD is chronic and progressive. It tends to fluctuate in severity often worsening in summer. Some people respond well to oral isotretinoin or acitretin but most often the condition relapses when the medication is stopped.
There is a small risk of progression to cutaneous squamous cell carcinoma, so the skin lesions should be monitored.
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