A Clinical and Histopathologic Observation of 79 Cases of Porokeratosis / 대한피부과학회지

ABSTRACT

BACKGROUND: Porokeratosis is a rare disorder characterized by an abnormal keratinization. Five different clinical types have been described, however most reports are on a small scale and rest,ricted to a particular type. OBJECTIVE: We tried to distinguish clinical and histopathologi'cal feat.ures of each type of porokeratosis. Methods: All patients with porokeratosis visiting the Dermatological Department of Chonnam University Hospital were retrospectively reviewed and finally 79 patients were evaluated. RESULTS: Disseminated superficial actinic porokeratosis(DSAP) was most common it was present in 44 patients(56%). This was f'ollowed by the plaque type(28%), linear type(14%) and punctate type(2%). The;oungest average age of onset was in the linear type at 13 years old (range 2-34 years old), and the oldest in DSAP which appeared in all patients after the age of 20. The plaque type was predominant in males 2.6 times rnore than in females. The predilection sites were the trunk in the plaque type, the unilateral lower limbs in the linear type and the face lower limbs in DSAP. 1tching was a complaint in 71% of DSAP and pain was in 14% of t.he plaque type. DSAP revealed a family history in 23% and a solar exacervation in 41%. Three cases of the plaque type t ad a malignant change. The average number of cornoid lamella per section was 1.8(ranging from one to seven). The height and invagination depth of cornoid lamellae were most prominent in the plaque type, and the le~ast in DSAP. Dysk(ratotic cells and vacuolar cell degenerat,ion in t.he underlying epidermis were most frequent in the plaque type. However dermal melanophage were present in DSAP. The Epidermis inside ring ofo~rnoid lamella was acanthotic chiefly in the plague type and atrophic chiefly in DSAP. CONCLUSION: These resuts demonstrate that each type of porokeratosis is somewhat, different in clinical and histopathological features.