Skin eruption usually begins in childhood
(although it can appear at any age), with asymptomatic porokeratotic lesions
on sun-exposed skin. Individual lesions begin as keratotic papules that
slowly enlarge to form characteristic annular plaques. The central portion
is usually hairless, slightly atrophic, and hypopigmented, although
hypertrophy and hyperpigmentation may occur. A raised border may occur and
can be up to 1 cm (0.4 inches) in height. Lesions have been reported on the
face and on the oral mucosa. They appear most often on the limbs and show a
tendency to centrifugal spread. The face, genitalia, oral mucosa, and cornea
may be affected. Approximately 7% of patients eventually develop skin
cancer (squamous cell and basal cell carcinomas), usually on the
extremities. Quiescent lesions become active and extensive after
immunosuppression for heart or renal transplantation. Various treatment
modalities were used, with no one method being more superior to another.
Patients should be advised to avoid excessive sunlight, to use sunscreen,
and to have periodic examinations by a dermatologist with a view to close
skin malignancy surveillance. There are no other associated anomalies.