Palmoplantar keratoses (overview)Q82.8

Hereditary or sporadically acquired cornification disorder of the palms and soles. Acquired PCD usually occurs later in life, has no genetic background, and can usually be further attributed etiopathogenetically by a subtle history. A hereditary PKK will be suspected if the first manifestation occurs in early childhood, a positive family history, resistance to therapy and a permanently present clinical picture are present.

According to clinical spectra, hereditary palmoplantar keratoses can be divided as follows:

Diffuse PKK

• Keratosis palmoplantaris diffusa with mutations in KRT 1 (Keratosis extremitatum hereditaria transgrediens et progrediens type Greither)
• Keratosis palmoplantaris diffusa with mutations in KRT 9 (Keratosis palmoplantaris diffusa circumscripta Unna-Thost (mutation of the KRT9 gene)
• Keratosis palmoplantaris cum degeneratione granulosa -type Vörner (mutation of KRT9/1 gene)
• Keratosis palmoplantaris transgrediens et progrediens with mutations in SLURP1 (Mal de Meleda; mutation of the SLURP1 gene)
• Keratosis palmoplantaris with scleratrophy (Huriez syndrome)
• Keratosis palmoplantaris with mutations in connexin 26
• Bart-Pumphrey syndrome with mutations in connexin 26 (GJB2 gene)
• Keratosis palmoplantaris, aquagenic, diffuse, with mutation in AQP5 (Bothnia type) (mutation of AQP5 gene aquaporin)
• Keratosis plamoplantaris type Nagashima (mutation of SERPINB7 gene)
• Loricrin keratoderm (mutation in the loricrin gene)

• Keratosis palmoplantaris aquagene with mutation in CFTR

• Clericuzio-type poikiloderma with neutropenia, recurrent sinopulmonary infections, pachyonychia, and palmo-plantar hyperkeratosis. Mutations in the C16orf57 gene located on chromosome 16q13.

Diffuse mutilating PKK

• Keratosis palmoplantaris mutilans -Vohwinkel syndrome- mutation of GJB2 gene - connexin 26).
• Loricrin keratoderm - ichthyosiform variant of Vohwinkel syndrome also Camisa syndrome (mutation of LOR gene)
• Olmsted syndrome - mutating PKK with perioral, perianal hyperkeratosis and enoral leukokeratosis (mutaion: TRPV3 gene)
• Keratosis linearis-Ichthyosis congenita-Keratoderma with mutations in POMP (click syndrome; transgressive palmoplantar keratosis with transgression on flexor sides of larger joints)

Focal/punctate PKK

• Keratosis palmoplantaris papulosa with mutation in AAGAB (Keratosis palmoplantaris papulosa - Buschke-Fischer-Brauer)
• Acrokeratoelastoidosis (Punctate palmoplantar keratosis type3)

Striated PKK

• Keratosis palmoplantaris striata with mutations in desmoglein 1 (old: Keratosis palmoplantaris striata -Brünauer-Fuhs-Siemens)
• Keratosis palmoplantariswith mutations in desmoplakin (Carvajal sydrome)
• Keratosis palmoplantaris with mutations in plakophilin 1(ectodermal dysplasia skin fragility syndrome)

Ectodermal dysplasias

• Incontinentia pigmenti, Franceschetti-Jadassohn-Naegeli type - Naegelie-Franceschetti syndrome-Jadassohn syndrome (mutation of KRT14 gene)
• Pachyonychia congenita with mutations in KRT6A/16) (Jadassohn-Lewandowski syndrome)
• Pachyonychia congenita with mutations in KRT6B/17) (Jackson-Lawler syndrome)
• Keratosis palmoplantaris diffusa with mutations in cathepsin C (Papillon-Lefèvre syndrome)
• Schöpf-Schulz-Passarge syndrome with mutation in WNT10A (palmoplantar keratosis with eyelid cysts,hypodentia and hypotrichosis .

Other and syndromic PKK

• Keratosis palmoplantaris with sp inykeratoses (Spiny Keratoderma)
• Keratosis palmaris et plantaris cum surditate congenita et leuconychia totalis unguium (Schwann syndrome)
• Keratosis palmoplantaris with tyrosinemia with mutation in TAT (Richner-Harnhard syndrome)
• Keratosis palmoplantaris with hypotrichosis
• Keratosis palmoplantaris withesophageal carcinoma (Howel-Evans syndrome) with mutation in iRHBDF2
• Keratosis palmoplantaris with clock glass nails and bone hypertrophy
• Keratosis palmoplantaris with hypopigmentation (Cole Disease)
• Keratosis palmoplantaris with mutations in plakoglobin (Naxos syndrome)

Clinical: The following aspects are indicative for PPK: beginning in childhood, positive FA, cosanguinity of the parents. Infection of other organ systems: hair, nails, hyperhidrosis, blistering, hearing and vision problems; neurological symptoms; resistance to therapy.

Genetic: The various Although the various forms of PKK are genetically very variable, they usually involve genes that code for epidermal structural proteins or different types of proteins. These genes code for epidermal structural proteins or control various processes during epidermal differentiation.

All acquired palmoplantar keratoses are important in the differential diagnosis:

Diffuse:

• Psoriasis palmoplantaris
• Hyperkeratotic-rhagadiform (tylotic) hand eczema
• Sezary syndrome
• Calluses
• Pityriasis rubra pilaris

Paraphrased:

• Verrucae (viral warts)
• Pits in Darier's disease
• Psoriasis palmoplantaris (streaky or circumscribed roundish)
• Syphilitic clavi

A cure for the genetically caused PKK is currently not possible. Symptomatic therapy is indicated according to the individual clinical pictures. See under the individual clinical pictures.

1. Blaydon DC et al (2013) Mutations in AQP5, encoding a water-channel protein, cause autosomal-dominant diffuse nonepidermolytic palmoplantar keratoderma. Am J Hum Genet 93:330-335

2. Brown-Falco M(2018) Ichthyoses. In: Braun-Falco`s Dermatology, Venereology Allergology G. Plewig et al (eds) Springer Verlag pp 1092-1093.

3. Dahlqvist J et al (2010) A single-nucleotide deletion in the POMP 5' UTR causes a transcriptional switch and altered epidermal proteasome distribution in KLICK genodermatosis. Am J Hum Genet 86:596-603.

4. Has C et al (2016) Keratosis palmoplantaris: clinical and genetic aspects JDDG 14: 123-142.

5. Schiller S et al (2014) Palmoplantar keratoses (PKK): acquired and genetic causes of a not so rare condition. JDDG 12: 781-793