Bazex Syndrome

Bazex syndrome is a rare paraneoplastic syndrome characterized by acral psoriasiform lesions.

Epidemiology

To date, approximately 145 cases have been reported in the literature. The syndrome most commonly affects males over 40 years of age (mean age of onset: 61 years), and only 12 female patients have been reported so far.

Clinical description

Patients present with asymptomatic and symmetrical, acral, erythemato-squamous psoriasiform eruptions. The most common sites of involvement are the ears (79%), nails (75%), nose (63%), fingers (61%), hands (57%), and feet (50%). Isolated involvement of the helices of the ears is typical. Lesions may extend to the cheeks, elbows, knees and trunk. Pruritus can occur in up to 18% of cases. Histological findings are not specific and include psoriasiform epidermal hyperplasia, hyperkeratosis with parakeratosis, and perivascular lymphocytic infiltrates in the dermis. In 70% of the cases, the cutaneous lesions precede the symptoms or diagnosis of the malignancy, which is most often a squamous cell carcinoma involving the upper aerodigestive tract.

Etiology

The pathogenesis of Bazex syndrome remains unknown. It may be caused by the production of epidermal growth factor by tumor cells or by cross-reactivity between epidermal and tumor antigens.

Diagnostic methods

Diagnosis is based on clinical and histological findings. Complete evaluation of the upper aerodigestive tract should be performed to identify the underlying malignancy.

Differential diagnosis

Differential diagnoses include psoriasis, allergic contact dermatitis, photosensitivity, dermatomyositis (see this term), drug eruption, cutaneous lupus erythematosus (see this term) and mycosis.

Management and treatment

The dermatosis may respond to acitretin alone or to a combination of acitretin and UVA phototherapy. Cutaneous lesions regress with the treatment of the underlying malignancy, whereas nail lesions may persist. Recurrence of skin lesions in a successfully treated patient implies a recurrence of the malignancy.

Prognosis

Prognosis is related to the underlying neoplasm.