Symmetrical acral keratoderma revisited: proposal for a new term, 'pigmented carpotarsal hyperkeratosis'.

First reported from Taiwan mistakenly as acral acanthosis nigricans in 1991, pigmented carpotarsal hyperkeratosis or hyperkeratosis nigricans carpi et tarsi displays a peculiar distribution of velvety brown-grey hyperpigmented plaques symmetrically on the flexural side of the wrists and ankles and on the dorsal sides of the hands and feet. A marked epidermal hyperkeratosis with typically mild acanthosis and papillomatosis is observed in histology. Whitish maceration upon perspiration or water exposure, with exacerbation in summer but remission in winter, is common. The association with obesity, endocrine disorders, atopic dermatitis, ichthyosis or malignancy is unknown. Familial occurrence and hereditary patterns are ill-defined. There is preliminary evidence indicating a pathogenic role of missense mutation in the transcription factor 4 gene. Treatment is empirical, with good outcome with topical retinoids and keratolytic agents. Recurrence is common, and long-term prognosis is unclear. To be distinguished are acral acanthosis nigricans, palmoplantar keratoderma of the Nagashima type, palmoplantar keratoderma of the Bothnian type and aquagenic palmoplantar keratoderma. Most reported cases are from Southern China and are predominantly observed in men between the ages of 20 and 40 years. The currently used term 'symmetrical acral keratoderma' is non-specific and misleading and may lead to global unawareness, underreporting or misdiagnosis of this phenomenon. Further genetic and molecular studies are required to clarify its pathogenesis and relation to palmoplantar keratoderma.

Hereditary palmoplantar keratodermas. Part I. Non-syndromic palmoplantar keratodermas: classification, clinical and genetic features.

The term palmoplantar keratoderma (PPK) indicates any form of persistent thickening of the epidermis of palms and soles and includes genetic as well as acquired conditions. We review the nosology of hereditary PPKs that comprise an increasing number of entities with different prognoses, and a multitude of associated cutaneous and extracutaneous features. On the basis of the phenotypic consequences of the underlying genetic defect, hereditary PPKs may be divided into the following: (i) non-syndromic, isolated PPKs, which are characterized by a unique or predominant palmoplantar involvement; (ii) non-syndromic PPKs with additional distinctive cutaneous and adnexal manifestations, here named complex PPKs; (iii) syndromic PPKs, in which PPK is associated with specific extracutaneous manifestations. To date, the diagnosis of the different hereditary PPKs is based mainly on clinical history and features combined with histopathological findings. In recent years, the exponentially increasing use of next-generation sequencing technologies has led to the identification of several novel disease genes, and thus substantially contributed to elucidate the molecular basis of such a heterogeneous group of disorders. Here, we focus on hereditary non-syndromic isolated and complex PPKs. Syndromic PPKs are reviewed in the second part of this 2-part article, where other well-defined genetic diseases, which may present PPK among their phenotypic manifestations, are also listed and diagnostic and therapeutic approaches for PPKs are summarized.

Disseminated punctate keratoderma: a rare case report and review of the literature.

We report a rare case of a 53-year-old womanpresenting with diffuse, late-onset disseminatedhyperkeratotic papules. Biopsy showed massivehyperkeratosis overlying a crateriform epidermaldepression and hypergranulosis with mild epidermalhyperplasia. There was no parakeratosis, cornoidlamella, or dyskeratosis. Based on the clinical findingsand histopathological features, a diagnosis ofdisseminated punctate keratoderma was made. Thisis a rare subtype of palmoplantar keratoderma, whichhas a putative increased risk of malignancy. This casereport emphasizes the importance of identifyingthe clinical and histological presentation of this rarecondition; referral of the patient for age-appropriatemalignancy screening is appropriate. We also presenta concise review of treatment options.

Hereditary palmoplantar keratoderma "clinical and genetic differential diagnosis".

Hereditary palmoplantar keratoderma (PPK) is a heterogeneous group of disorders characterized by hyperkeratosis of the palm and the sole skin. Hereditary PPK are divided into four groups--diffuse, focal, striate and punctate PPK--according to the clinical patterns of the hyperkeratotic lesions. Each group includes simple PPK, without associated features, and PPK with associated features, such as involvement of nails, teeth and other organs. PPK have been classified by a clinically based descriptive system. In recent years, many causative genes of PPK have been identified, which has confirmed and/or rearranged the traditional classifications. It is now important to diagnose PPK by a combination of the traditional morphological classification and genetic testing. In this review, we focus on PPK without associated features and introduce their morphological features, genetic backgrounds and new findings from the last decade.

Palmoplantar keratoderma of the Gamborg-Nielsen type is caused by mutations in the SLURP1 gene and represents a variant of Mal de Meleda.

Palmoplantar keratoderma of the Gamborg-Nielsen type (PPK-GN) is a rare autosomal recessive skin disorder described in patients from Sweden. Mal de Meleda (MDM) is also a rare autosomal recessive inherited PPK first reported in 5 families from the island of Meleda. The 2 conditions phenotypically overlap and are characterised by palmoplantar erythematous hyperkeratotic plaques. The genetic background giving rise to PPK-GN has hitherto been unknown, whereas MDM is known to be caused by mutations in the gene encoding secreted Ly-6/uPAR-related protein 1, SLURP-1. In the present study we scrutinised individuals affected by PPK-GN for mutations in the SLURP1 gene and identified 2 different mutations. Fourteen Swedish patients were homozygous for a previously described mutation, c.43T>C, while one individual was a compound heterozygote with one copy of a novel mutation, c.280T>A, in addition to one copy of the c.43T>C mutation. Hereby we confirm that PPK-GN is an allelic variant of MDM.

A review of the clinical phenotype of 254 patients with genetically confirmed pachyonychia congenita.

BACKGROUND: Pachyonychia congenita (PC) is a group of autosomal dominant keratinizing disorders caused by a mutation in one of 4 keratin genes. Previous classification schemes have relied on data from case series and case reports. Most patients in these reports were not genetically tested for PC. OBJECTIVE: We sought to clarify the prevalence of clinical features associated with PC. METHODS: We surveyed 254 individuals with confirmed keratin mutations regarding their experience with clinical findings associated with PC. Statistical comparison of the groups by keratin mutation was performed using logistic regression analysis. RESULTS: Although the onset of clinical symptoms varied considerably among our patients, a diagnostic triad of toenail thickening, plantar keratoderma, and plantar pain was reported by 97% of patients with PC by age 10 years. Plantar pain had the most profound impact on quality of life. Other clinical findings reported by our patients included fingernail dystrophy, oral leukokeratosis, palmar keratoderma, follicular hyperkeratosis, hyperhidrosis, cysts, hoarseness, and natal teeth. We observed a higher likelihood of oral leukokeratosis in individuals harboring KRT6A mutations, and a strong association of natal teeth and cysts in carriers of a KRT17 mutation. Most keratin subgroups expressed a mixed constellation of findings historically reported as PC-1 and PC-2. LIMITATIONS: Data were obtained through questionnaires, not by direct examination. Patients were self- or physician-referred. CONCLUSIONS: We propose a new classification for PC based on the specific keratin gene affected to help clinicians improve their diagnostic and prognostic accuracy, correct spurious associations, and improve therapeutic development.

Diagnóstico diferencial de la queratodermia palmoplantar: [revisión] / Differential diagnosis of palmoplantar keratoderma in clinical practice: [review]

Las queratodermias palmoplantares representan un grupo heterogéneo de enfermedades caracterizadas por el engrosamiento anormal de la piel de las palmas de las manos y las plantas de los pies. La alteración de base es la excesiva formación de queratina. Existen variedades adquiridas vinculadas a otras enfermedades, como el caso del hidroarsenicismo crónico regional endémico. También existen numerosas formas congénitas de las cuales se han ido descubriendo los genes mutados y su localización cromosómica. En general, los genes mutados codifican para proteínas del tipo conexinas, relacionadas con la diferenciación celular conocida como "gap junction". Si bien se trata de una enfermedad eminentemente dermatológica, el clínico puede ser consultado dado que algunas causas adquiridas pueden ser inicialmente observadas por el internista. Se presenta una puesta al día que abarca las queratodermias palmoplantares congénitas con manifestaciones asociadas y sin ellas y las formas adquiridas.(AU)

Diagnóstico diferencial de la queratodermia palmoplantar: [revisión] / Differential diagnosis of palmoplantar keratoderma in clinical practice: [review]

Las queratodermias palmoplantares representan un grupo heterogéneo de enfermedades caracterizadas por el engrosamiento anormal de la piel de las palmas de las manos y las plantas de los pies. La alteración de base es la excesiva formación de queratina. Existen variedades adquiridas vinculadas a otras enfermedades, como el caso del hidroarsenicismo crónico regional endémico. También existen numerosas formas congénitas de las cuales se han ido descubriendo los genes mutados y su localización cromosómica. En general, los genes mutados codifican para proteínas del tipo conexinas, relacionadas con la diferenciación celular conocida como "gap junction". Si bien se trata de una enfermedad eminentemente dermatológica, el clínico puede ser consultado dado que algunas causas adquiridas pueden ser inicialmente observadas por el internista. Se presenta una puesta al día que abarca las queratodermias palmoplantares congénitas con manifestaciones asociadas y sin ellas y las formas adquiridas.

Nonmutilating palmoplantar and periorificial kertoderma: a variant of Olmsted syndrome or a distinct entity?

BACKGROUND: Olmsted syndrome is a rare keratinization disorder characterized by mutilating palmoplantar and periorificial keratoderma as the two major diagnostic features. Some authors believe that atypical cases without this standard combination may not really belong to Olmsted syndrome. Herein, we describe two familial cases with congenital nonmutilating palmoplantar and periorificial keratoderma, and discuss their similarities and differences with Olmsted syndrome. PATIENTS: The study included two sisters who presented with focal and punctate nonmutilating palmoplantar keratoderma (PPK), periorificial hyperkeratotic plaques, and widely distributed keratotic lesions. Fragile denuded areas of the skin were found in sites exposed to trauma. Fingernails showed a characteristic form of leukonychia. RESULTS: Histopathology of plantar keratoderma showed psoriasiform hyperplasia with marked compact hyperkeratosis, while vicinity of denuded skin revealed thin parakeratotic zone and dissolution of the granular cell layer. Immunohistochemistry demonstrated suprabasal staining pattern for acidic keratin (AE1) and uniform positivity, starting four to six layers above the basal layer, for cytokeratin 10. Electron microscopy showed defective keratinization. Cytogenetic studies revealed normal karyotype and no chromosomal breakage. CONCLUSION: Our cases share Olmsted syndrome in the early onset, and the presence of symmetrical PPK, periorificial keratoderma and keratotic lesions. However, the striking nonmutilating nature of PPK and the presence of unique features in our patients suggest a newly described keratinization disorder.

The hand-foot-syndrome associated with medical tumor therapy - classification and management.

The hand-foot-syndrome (HFS, palmoplantar erythrodysesthesia, chemotherapy-associated acral erythema) is characterized by painful predominantly palmo-plantar lesions. The association with different chemotherapeutic agents has been known for over 20 years. More recently, HFS has been reported in association with regimens using targeted agents, in particular the multikinase inhibitors (MKI) sorafenib and sunitinib. The HFS associated with MKI has a different distribution and clinical appearance than the traditional disorder. In this review, similarities and differences between chemotherapy- and MKI-associated HFS are discussed and current recommendations for their prophylaxis and management are summarized.

Vohwinkel Syndrome secondary to missense mutation D66H in GJB2 gene (connexin 26) can include epileptic manifestations.

Vohwinkel Syndrome (VS) is a type of diffuse hereditary palmoplantar keratodermas (DHPPK) accompanied by skeletal dimorphisms and sensorineural deafness. The most frequently reported genetic substrate in VS is a point mutation of GJB2 gene, responsible for encoding connexin 26, a gap-junction protein with a crucial role in neuronal migration in rats. We report the case of a 21-year-old male who is a second-generation member of a family with VS and developed cryptogenic focal epilepsy. Genetic study showed a nucleotide change (c.196G>C) in exon 1 of GJB2 gene, producing a missense mutation, D66H. It is plausible that a functional alteration of connexin 26, such as that resulting of the mutation of our case, can produce an alteration in cortical development with epileptogenic potential. The present case and experimental evidence that connexin 26 is related to animal epileptogenesis suggest that the phenotypic spectrum of VS could be expanded to include epileptic manifestations.

[Keratoderma palmoplantaris varians (striata et areata), a form of chronic idiopathic acrokeratosis described by Degos]. / Queratodermia palmoplantar varians (striata et areata) tipo acroqueratosis esencial crónica de Degos.

We report a case of a 15-year-old boy with hyperkeratotic lesions that were linear or striated on the palms and nummular on the soles. He was the only family member known to be affected, suggesting that the condition could be attributed to a de novo mutation or the recessive form of keratoderma palmoplantaris striata, described by Degos as chronic idiopathic acrokeratosis. The lesions did not improve with topical treatments (keratolytic agents, emollients, or corticosteroids) or oral retinoids. We observed that scratching of the affected areas was the main reason for deterioration of the lesions.

Unilateral transient reactive papulotranslucent acrokeratoderma in a child.

Transient reactive papulotranslucent acrokeratoderma is a rare, acquired, reactive, and episodic disorder of the palmar skin. Herein I report on a 6-year-old child with unilateral involvement and associated with ipsilateral hyperhidrosis and pruritus. Further observations are required for unraveling the etiopathogenesis of this disorder and its accurate classification.

[Autosomal dominant punctate palmoplantar keratoderma]. / Queratodermia palmoplantar punctata autosómica dominante.

Hereditary punctate palmoplantar keratoderma or Buschke-Fisher-Brauer disease is a rare form of keratoderma that follows a pattern of autosomal dominant inheritance with variable penetrance. The age of onset is usually between 12 and 30 years of age. Clinically, it is characterized by the gradual appearance of multiple punctate hyperkeratotic papules, irregularly distributed on the palms and soles, as well as by its possible association with several diseases, primarily with malignant processes. We present the case of a 43-year-old male patient with this disease, with no other associated symptoms, who had a first-degree relative who was affected and died of colon cancer. We also discuss the differential diagnosis with other nosologic entities.