DEFINITION: Porokeratosis is a chronic progressive skin condition in which there are multiple abnormal skin patches with dry, atrophic center and elevated warty border in circumscription of each lesion, like a collar, felt to be due to faulty keratinization or the process of forming the protective texture for the surface of the skin.

 

PRESENTATION: The condition is observed to be hereditary, seen often to be transmitted from father to son, and with male having twice the incidence as female. It has a predilection for the skin surfaces of the hands, the fingers, the ankles, and the feet, although it may also be seen involving the face, the buccal mucosa, and the gland penis. Porokeratosis usually begins early in life and irreversible progress and becomes chronic. The individual lesions may or may not be painful depending on the sites and the magnitude of irritation. There are several distinctive forms of porokeratosis.

 

1. Disseminated superficial actinic porokeratosis presents with numerous superficial, ring-like, red to brownish flat lesions less than 1 cm in diameter, on sun-exposed surface. About 20 to 40% of the lesions enlarge over time.

 

2. Porokeratosis Palmaris Plantares et Disseminata lesions distinctively appear first on the palms and soles, and then distribute to other body areas.

 

3. Porokeratosis Plantaris Discreta this form of lesion is seen mostly in female localizing to the weight-bearing area of the sole. It is seen with a sharply marginated, rubbery, wide-based focal skin elevation, less than 1 cm, and has a more opaque central clearing. It is often painful.

 

CAUSE: Porokeratosis is observed to be a result of abnormal growing clones of skin forming cells, which lead to keratinization, or the process of forming the protective texture for the surface of the skin, that is defective. The midlayer of the skin also displays an infiltration cells.

 

THERAPY: Over the years we have tried cryotherapy, 5 fluoro-uracil cream, Tretinoin cream, alpha hydroxy acid cream, More recently Vitamin-A drugs in oral and ointment form have been tried, but nothing has proved very effective. Porokeratosis is usually treated with topical 5% Fluorouracil cream, or derivatives of Vitamin A, etretinate and isoretinoin. Sometimes, liquid nitrogen or local excision are also employed.