History:

Porokeratosis of Mibelli, first described by Mibelli in 1893, is generally transmitted as an autosomal dominant trait but may occur spontaneously.  The lesions develop as annular, dry plaques surrounded by an elevate keratotic margin and sometimes also a furrow. The centre is often atrophic but may be hyperkeratotic. Management includes avoidance of sun exposure, use of sunscreens, topical 5-FU, topical vitamin D-3 , topical tretinoin and oral retinoids, cryotherapy, electrodessication, curettage, dermabrasion and laser therapy. Surgical excision is most appropriate when malignant degeneration develops. The prognosis is generally good if there is no underlying immunosuppression.