Porokeratosis Plantaris Palmaris Et Disseminata

A rare genetic disease which is a rare form of porokeratosis occurring mainly in adolescence and characterized by small pruritic or painful keratotic papules that first appear on the palms and soles, and may gradually spread to other body zones.

Epidemiology

Porokeratosis plantaris palmaris et disseminata (PPPD) prevalence is unknown but it is one of the rarest forms of porokeratosis. The disease is more frequently seen in males.

Clinical description

The disease often begins in adolescence but some cases have presented in adulthood. Keratotic papules are first noticed on the palms and soles but later spread over the entire body, although lesions on the trunk might be less keratotic. The lesions are usually punctate on the palms and soles and annular on the rest of the body with the characteristic hyperkeratotic border. Foot pain is common due to plantar keratoses. Men are more often affected than women.

Etiology

The exact etiology is unknown. A possible locus for PPPD has been found on chromosome 12q24.1-q24.2.

Diagnostic methods

Diagnosis is based on physical examination and a cutaneous biopsy showing the distinctive pathologic finding known as cornoid lamella. The characteristic clinical findings of papular-keratotic, rather than annular, lesions and an initial onset on the palms and soles also aids in the diagnosis.

Differential diagnosis

Differential diagnoses include other (genetic) punctate palmoplantar keratodermas such as acrokeratoelastoidosis of Costa, hyperkeratosis-hyperpigmentation syndrome, punctate palmoplantar keratoderma type 1 and hereditary papulotranslucent acrokeratoderma.

Genetic counseling

PPPD usually follows a dominant (autosomal or X-linked) pattern of inheritance. Sporadic cases have been reported and may be due to spontaneous mutations resulting in abnormal proliferating clones of epidermal cells.

Management and treatment

There is no standard treatment for PPPD. Oral retinoids combined with topical 5-fluorouracil (5-FU) have been successful in reducing the number of lesions in some patients, but relapses are common. Physical methods (shave excision, cryotherapy, curettage, dermabrasion and linear excision) have had varying degrees of success in removing lesions but are not a feasible option in cases where the lesions are generalized.

Prognosis

PPPD has a negative impact on a patient's quality of life as the lesions are tender or painful, limiting the patient's ability to walk, and their treatment is often unsuccessful.