Porokeratotic Eccrine Ostial and Dermal Duct Naevus (PEODDN) is a rare congenital disorder of keratinisation. Keratinisation is the process by which the skin cells form in the epidermis. PEODDN is a special type of epidermal naevus.
Porokeratotic eccrine and hair follicle naevus is a very similar entity.
PEODDN is usually present at birth (a birthmark) and becomes more apparent as the person becomes older. However, some cases of PEODDN have been reported to develop for the first time after puberty.
PEODDN is characterised by small discrete scaly papules arranged in a line, most commonly on the palm of the hand (or fingers) or or sole of the foot (or toes). It may extend onto the backs of the hands and feet. There are rare cases of extensive lesions affecting large parts of the body. PEODDN usually becomes more warty in appearance over time and nearly always persists despite treatment.
PEODDN is usually not associated with any symptoms, although, occasionally it can be a bit itchy.
Treatments aimed at reducing the thickness of the warty skin in the affected area include:
These treatments are only partly effective.
Destructive methods such as laser resurfacing (e.g CO2 laser), dermabrasion or excision of the area may be used to treat localised PEODDN, sometimes successfully.
