[Porokeratosis. A study about 6 cases].

Background: Porokeratoses (PK) represent a less common group of dermatoses that are acquired or hereditary, of unknown pathogenesis, characterized by keratinization disorder. Different clinical forms have been identified and the most frequent are the Mibelli's porokeratosis (MP) and the Disseminated Superficial Actinic Prokeratosis (DSAP).

Aim: In this retrospective study, we analysed the observations of PK collected in the Dermatology Department of La Rabta Hospital over a 16-year period.

Methods: Six cases of PK were collected: 4 females and 2 males, with no medical history with a mean-age of 42.7.

Results: Only a female patient had (PK) familial history. All our patients had typical clinical aspects with lesions in annular plaques, of atrophic center, surrounded by keratotic border. The histological aspect was consistent with PK, showing the typical cornoid slide. In our series, there are 3 cases of (MP) and 3 cases of (DSAP). PK lesions usually appear during the childhood and the third and fourth decades for the DSAP. In MP, there is one or some large, unilateral, annular plaques. DSAP is characterized by numerous small annular lesions of the photo-exposed regions. Their prognosis is on the whole, favourable but remains conditioned by malignant transformation. Treatment is difficult aiming at reducing that risk of degeneration.