Papillon-Lefèvre Syndrome
Papillon-Lefèvre syndrome (PLS) is a rare ectodermal dysplasia characterized by palmoplantar keratoderma associated with early-onset periodontitis.
Epidemiology
The prevalence is estimated between 1/250,000 and 1/1,000,000 individuals. The male to female ratio is 1:1. PLS is found in all ethnic groups.
Clinical description
Diffuse palmoplantar keratoderma (see this term) with erythematous plaques develops between the first and fourth years of life, with the soles being usually more severely affected than the palms. Psoriasiform hyperkeratosis can overflow onto the dorsal surfaces of the hands and feet (transgredient spread) and, less frequently, lesions can be seen on the limbs (knees, elbows). Skin lesions are followed by intense gingivitis that rapidly progresses into periodontitis with alveolar bone lysis and early loss of primary dentition. The skin lesions are aggravated by cold and during episodes of severe periodontitis. During childhood, the phenomenon of periodontal disease recurs with rapid loss of permanent dentition. Cases of PLS with mild and/or late-onset periodontal disease have been reported occasionally. PLS is accompanied, in half of the patients, by enhanced susceptibility to cutaneous and systemic infections (furunculosis, skin abscesses, pyoderma, hidradenitis suppurativa (see this term), respiratory tract infection...). Patients may also present with malodorous hyperhidrosis, follicular hyperkeratosis, nail dystrophy or dural calcifications. The association of PLS with malignant melanoma or squamous cell carcinoma has been reported in very rare occasions.
Etiology
PLS is due to mutations in the CTSC gene (11q14.2) that codes for cathepsin C (also known as dipeptidyl peptidase I), a lysosomal protease playing a role in epidermal differentiation and desquamation and in activation of serine proteases expressed in cells of the immune system. CTSC mutations lead to an almost total loss of cathepsin C activity which seems to result in susceptibility to specific virulent pathogens. It is also suggested that other immune-mediated deficiencies in the host defense mechanism could be involved in the pathogenesis of PLS.
Diagnostic methods
Diagnosis is based on clinical signs. Dental radiography shows atrophy of the alveolar bone. Neutrophil function tests reveal anomalies of chemotaxis and phagocytosis by polymorphonuclear leukocytes. Skin biopsy shows hyperkeratosis with focal parakeratosis, moderate perivascular infiltration, hypergranulosis, and acanthosis. Biochemical analysis reveals a loss of CTSC activity. Diagnosis is confirmed by genetic testing.
Differential diagnosis
Differential diagnosis includes two rare disorders that are allelic variants of PLS, Haim-Munk syndrome (see this term) and prepubertal/aggressive periodontitis. Other diseases with similar dermatologic features include localized epidermolytic palmoplantar keratoderma (Vörner), mal de Meleda, Howel-Evans syndrome, transgrediens et progrediens palmoplantar keratoderma (Greither's disease) (see these terms), and keratosis punctata.
Antenatal diagnosis
Antenatal diagnosis is theoretically possible but has never been reported.
Genetic counseling
Transmission is autosomal recessive. Genetic counseling should be offered to the parents of an affected individual informing them of the 25% risk their offspring has of inheriting the disease causing mutation.
Management and treatment
Treatment is based on oral retinoids which attenuate the palmoplantar keratoderma and slow the alveolar bone lysis. Antibiotics, along with oral hygiene and use of mouth rinses, are also recommended for slowing the progression of periodontitis. Ultimately, primary or remaining teeth are extracted and are replaced by dental implants. Antibiotherapy is also used in the treatment of recurrent infections. Etretinate (a synthetic retinoid) shows promising results in the treatment of PLS.
Prognosis
Despite meticulous dental care, all patients eventually become edentulous at the beginning of adulthood. Life expectancy is normal.