Plantar keratoderma-like crusted scabies in an immunocompetent infant after topical steroids

A healthy 6-month-old girl presented with plantar keratoderma-like lesions unresponsive to topical corticosteroids. Nocturnal pruritus in 13 relatives, presence of burrows on clinical exam, and the positive scabies preparation led to the diagnosis of crusted scabies. She was successfully treated with topical and oral scabicides. Crusted scabies is a severe form of Sarcoptes scabiei infection uncommon in immunocompetent subjects, in whom previous corticosteroid use may favor its occurrence.

Nagashima-type palmoplantar keratoderma: Case series and two novel variants

Nagashima-type palmoplantar keratoderma (PPK) is an autosomal recessive PPK. We report four patients, highlight two new genetic variants, and emphasize the possibility of misdiagnosing the condition. Concomitant atopic dermatitis, specifically, may make correct diagnosis challenging. Clinicians should consider the diagnosis of Nagashima-type PPK in patients presenting with mild PPK with transgrediens and understand the importance of individualized multimodal treatment regimens.

Two for two: Dual therapy with erlotinib and acitretin for twins with severe keratoderma in Olmsted syndrome

Olmsted syndrome (OS) is a rare genetic disorder, characterized by painful palmoplantar keratoderma (PPK), periorificial and intertriginous hyperkeratoses, and alopecia. Fewer than 75 cases have been described. Variants in TRPV3 result in constitutive activation of transient receptor potential vanilloid 3, leading to increased epidermal growth factor receptor (EGFR) signaling, palmoplantar epidermal hyperproliferation, and exquisite lesional pain. We describe pre-school aged twins with OS with partial improvement from oral erlotinib, an EGFR inhibitor, but dramatic reduction of their persistent palmoplantar thickening and pain from adding acitretin.

Punctate Palmoplantar Keratoderma: A Case Report

Palmoplantar keratoderma (PPK) is an umbrella term for a group of heterogeneous disorders, acquired or inherited, that are characterized by hyperkeratosis of palmar and/or plantar surfaces. Punctate PPK (PPPK) has been shown to have an autosomal dominant pattern of inheritance. It is linked with two loci on chromosomes 8q24.13-8q24.21 and 15q22-15q24. In type 1 PPPK, also known as Buschke-Fischer-Brauer disease, loss-of-function mutations in either the AAGAB or the COL14A1 genes have been associated with the disorder. We report here the clinical and genetic features of a patient with findings most consistent with type 1 PPPK.

Keratoderma in Systemic Lupus Erythematosus: An Unusual Cutaneous Manifestation of Disease?

Systemic lupus erythematosus (SLE) is a multi-organ autoimmune disease, with the skin being the second most affected organ after the joints. We present a unique case of a 44-year-old female who presented with an acute flare of SLE and the concurrent onset of keratoderma on both lower limbs. She presented with high-grade fever, arthralgia, and generalized edema of four months duration. A general physical examination revealed pallor and scaly hyperpigmented plaques on both lower limbs, which was confirmed to be keratoderma on histopathological examination. Blood investigations revealed pancytopenia, elevated erythrocyte sedimentation rate (ESR) and C- reactive protein (CRP), and positive titers for anti-nuclear antibody (ANA) and anti-Po ribosomal P proteins (RPP) antibodies. Immunosuppressive medications and topical keratolytics were used to treat her successfully. Post medical management, she showed significant improvement in her symptoms. On follow-up, the patient had a complete resolution of the symptoms and remained well. This case demonstrates keratoderma as a rare incidental finding in a patient with SLE flare. Understanding SLE's various cutaneous manifestations are critical for holistically diagnosing and treating the disease.

Acral peeling in Nagashima type palmo-plantar keratosis patients reveals the role of serine protease inhibitor B 7 in keratinocyte adhesion

Acral peeling skin syndrome (APSS) is a heterogenous group of genodermatoses, manifested by peeling of palmo-plantar skin and occasionally associated with erythema and epidermal thickening. A subset of APSS is caused by mutations in protease inhibitor encoding genes, resulting in unopposed protease activity and desmosomal degradation and/or mis-localization, leading to enhanced epidermal desquamation. We investigated two Arab-Muslim siblings with mild keratoderma and prominent APSS since infancy. Genetic analysis disclosed a homozygous mutation in SERPINB7, c.796C > T, which is the founder mutation in Nagashima type palmo-plantar keratosis (NPPK). Although not previously formally reported, APSS was found in other patients with NPPK. We hypothesized that loss of SERPINB7 function might contribute to the peeling phenotype through impairment of keratinocyte adhesion, similar to other protease inhibitor mutations that cause APSS. Mis-localization of desmosomal components was observed in a patient plantar biopsy compared with a biopsy from an age- and gender-matched healthy control. Silencing of SERPINB7 in normal human epidermal keratinocytes led to increased cell sheet fragmentation upon mechanical stress. Immunostaining showed reduced expression of desmoglein 1 and desmocollin 1. This study shows that in addition to stratum corneum perturbation, loss of SERPINB7 disrupts desmosomal components, which could lead to desquamation, manifested by skin peeling.

[Genetics of complex and syndromic palmoplantar keratoderma]

Palmoplantar keratodermas (PPK) comprise a heterogenous group of acquired and hereditary disorders marked by excessive thickening of the epidermis of palms and soles. Hereditary PPKs can be classified into 3 groups: 1) isolated non-syndromic PPKs; 2) complex non-syndromic PPKs associated with other ectodermal defects; and 3) syndromic PPKs associated with extracutaneous manifestations. All types of inheritance have been observed: autosomal dominant, autosomal recessive, X-linked recessive, and mitochondrial. Some of these disorders are restricted to geographic isolates. This review describes the different genetic causes of hereditary syndromic and complex PPKs for which the genes have been identified. The identification of pathogenic variants has consequences in terms of genetic counseling, appropriate medical care and follow-up, especially for PPKs predisposing to hearing loss, cardiomyopathies, benign tumors or carcinomas. In addition, the development of targeted therapies based on pathophysiology of disorders should allow a more effective treatment of these conditions in the near future.

Two patients with Papillon-Lefèvre syndrome without periodontal involvement of the permanent dentition

Papillon-Lefèvre syndrome (PLS) is a rare autosomal recessive genodermatosis characterized by palmoplantar keratoderma and severe periodontitis leading to premature loss of primary and permanent teeth. PLS is caused by loss-of-function mutations in CTSC, lacking functional cathepsin C, which impairs the activation of neutrophil serine proteases. Precise pathogenesis of periodontal damage is unknown. Patient 1 presented with well-demarcated, transgredient, diffuse, palmoplantar keratoderma and psoriasiform lesions from the age of 2 years. Based on severe and recurrent periodontal inflammation, his dentist had diagnosed PLS at the age of 3 years and provided a strict oral hygiene regimen with repeated adjunct antibiotic therapies. Oral acitretin 10 mg/day along with tretinoin ointment at the age of 9 greatly improved palmoplantar keratoderma. Aged 18 years, the patient exhibited an intact permanent dentition and absence of periodontal disease. Patient 2, a 30-year-old man, suffered from transgredient, diffuse, palmoplantar keratoderma with fissuring from the age of 2 months, marked psoriasiform plaques on elbows and knees, and nail dystrophy. Intriguingly, without specific dental treatment, teeth and dental records were unremarkable. He was referred with a suspected diagnosis of psoriasis. Both patients were otherwise healthy, blood tests and sonography of internal organs were within normal limits. Panel sequencing revealed loss-of-function mutations in CTSC, c.322A>T (p.Lys108Ter) and c.504C>G (p.Tyr168Ter) in patient 1 and homozygous c.415G>T (p.Gly139Ter) in patient 2. The final diagnosis of unusual PLS was made. PLS should be considered in palmoplantar keratoderma lacking periodontitis or tooth loss.

Mutations in ASPRV1 Cause Dominantly Inherited Ichthyosis

The discovery of genetic causes of inherited skin disorders has been pivotal to the understanding of epidermal differentiation, function, and renewal. Here we show via exome sequencing that mutations in ASPRV1 (aspartic peptidase retroviral-like 1) cause a dominant Mendelian disorder featuring palmoplantar keratoderma and lamellar ichthyosis, a phenotype that has otherwise been exclusively recessive. ASPRV1 encodes a mammalian-specific and stratified epithelia-specific protease important in processing of filaggrin, a critical component of the uppermost epidermal layer. Three different heterozygous ASPRV1 missense mutations in four unrelated ichthyosis kindreds segregate with disease and disrupt protein residues within close proximity to each other and autocatalytic cleavage sites. Expression of mutant ASPRV1 proteins demonstrates that all three mutations alter ASPRV1 auto-cleavage and filaggrin processing, a function vital to epidermal barrier integrity.

Diagnosis and Management of Inherited Palmoplantar Keratodermas

Inherited monogenic palmoplantar keratodermas are a heterogeneous group of conditions characterised by persistent epidermal thickening of the palmoplantar skin. Palmoplantar keratodermas are grouped depending on the morphology of the keratoderma into diffuse, focal/striate or papular/punctate. Some palmoplantar keratodermas just affect the skin of the palms and soles and others have associated syndromic features which include changes in hair, teeth, nails, hearing loss or cardiomyopathy. Next generation sequencing has helped discover genes involved in many of these conditions and has led to reclassification of some palmoplantar keratodermas. In this review, we discuss the diagnostic features of palmoplantar keratodermas and management options.

Confirming the recessive inheritance of PERP-related erythrokeratoderma

Erythrokeratoderma (EK) is heterogeneous clinical entity characterized by excessive scaling with resulting erythrokeratotic plaques. Several genes have been linked to EK and they encode a number of proteins that are important for the integrity of the keratinocyte layer of the epidermis. PERP is a transcription factor that is activated by both p53 and p63. However, its deficiency in a mouse model appears to only recapitulate p63-mediated role in skin development and organization. We report an extended multiplex consanguineous family in which an EK phenotype with a striking similarity to that observed in Perp^-/- mice, is mapped to an autozygous region on chromosome 6 that spans PERP. Whole-exome sequencing revealed a novel variant in PERP that fully segregated with the phenotype. Functional analysis of patient- and control-derived keratinocytes revealed a deleterious effect of the identified variant on the intracellular localization of PERP. A previous report showed that PERP mutation causes a dominant form of keratoderma but a single patient in that report with a homozygous variant in PERP suggests that recessive inheritance is also possible. Our results, therefore, support the establishment of an autosomal recessive PERP-related EK phenotype in humans.

Spiny keratoderma: Report of three cases

BACKGROUND

Spiny keratoderma shows "music box spine" keratotic papules limited to the palms and soles and these lesions do not cause any trouble besides the cosmetic impairment and the sensation of roughness of hands and soles.

AIM

To present cases and review the literature on spiny keratoderma.

PATIENTS/METHODS, RESULTS

Three cases of spiny keratoderma are presented. The first case is a 52-year-old man with protein S deficiency presented with multiple spiny keratotic papules on palms and soles for more than 30 years, referring to remove them with a razor blade. The second case is an 84-year-old man who was hospitalized due to a rectal adenocarcinoma diagnosed 2 months before and presented multiples papules on palms and soles that were present for more than 50 years, with worsening after being bedridden. The third case is a 59-year-old woman who had since birth together with relatives the same type of spiny keratotic papules on palms and soles.

CONCLUSION

The authors discuss the epidemiologic data and differential diagnosis of spiny keratoderma, as well as the related literature. Associations with systemic disease or malignancy occur in some acquired cases. It is important to distinguish from other palmoplantar keratodermas as some of that can be linked to cutaneous and internal malignancies. To date, no cases of spiny keratoderma in patients with protein S deficiency and only one case of association with rectal carcinoma have been reported.

Mutation-Proved Clouston Syndrome in a Large Indian Family with a Variant Phenotype

Hereditary ectodermal dysplasias, a group of disorders affecting skin, hair, nails, and teeth, consist of two main clinical forms – hypohidrotic and hidrotic. Clouston syndrome is a hidrotic ectodermal dysplasia characterized by a triad of generalized hypotrichosis, palmoplantar hyperkeratosis, and nail dystrophy. This paper reports a large Indian family with Clouston syndrome but with the absence of palmoplantar keratoderma, one of the features of the typical triad, thus representing phenotypic heterogeneity, in spite of the presence of a common known mutation in GJB6 gene (p.Gly11Arg).

Compound heterozygous mutations in desmoplakin associated with skin fragility, follicular hyperkeratosis, alopecia, and nail dystrophy

Desmoplakin mutations are associated with a wide variety of phenotypes affecting the skin, nails, hair, and heart. A 21-month-old boy was born with multiple erosions resembling epidermolysis bullosa, complete alopecia, nail dystrophy, palmoplantar keratoderma, and areas of follicular hyperkeratosis. He was found to have two heterozygous mutations in the desmoplakin gene: c.478 C>T in exon 4 (p.Arg160X) and c.3630T>A in exon 23 (Tyr1210X). This case expands the clinical spectrum associated with desmoplakin mutations and highlights a mutation in exon 23 that has not been previously reported in the literature.

The keratin 16 null phenotype is modestly impacted by genetic strain background in mice

The type I intermediate filament keratin 16 (K16) is constitutively expressed in ectoderm-derived appendages and is inducibly expressed in the epidermis upon barrier-compromising challenges. Dominantly acting missense alleles in KRT16 are causative for pachyonychia congenita (PC), a genodermatosis involving debilitating palmoplantar keratoderma (PPK), nail dystrophy, oral lesions and, frequently, alterations in glands and hair. C57Bl/6;Krt16^-/- mice develop oral lesions early after birth and PC-like PPK lesions as young adults. These PPK lesions have a marked dysregulation of skin barrier-related genes and innate immunity effectors (eg danger-associated molecular patterns) and are preceded by oxidative stress secondary to hypoactive Nrf2 signalling. These molecular features are present in PPK lesions of PC patients. Here, we report that all components of the C57Bl/6;Krt16^-/- mouse phenotype occur as well in the FVB strain background, albeit less severely so, a significant observation in the light of variations in the clinical presentation of individuals harbouring disease-causing mutations in the KRT16 gene.

Olmsted Syndrome Caused by a Heterozygous p.Gly568Val Missense Mutation in TRPV3 Gene

Olmsted syndrome (OS) is a rare congenital skin disorder characterized by severe palmoplantar and periorificial keratoderma, alopecia, onychodystrophy, and severe pruritus. Recently, pathogenic 'gain-of-function' mutations of the transient receptor potential vanilloid 3 gene (TRPV3), which encodes a cation channel involved in keratinocyte differentiation and proliferation, hair growth, inflammation, pain and pruritus, have been identified to cause OS. Due to the rarity, the pattern of inheritance of OS is still unclear. We report a case of OS in a 3-year-old Korean girl and its underlying gene mutation. The patient presented with a disabling, bilateral palmoplantar keratoderma with onychodystrophy. She also exhibited pruritic eczematous skin lesions around her eyes, ears and gluteal fold. Genetic analysis identified a heterozygous p.Gly568Val missense mutation in the exon 13 of TRPV3. To our knowledge, this is the first case of OS in the Korean population showing a missense mutation p.Gly573Ser.

Duplicated Enhancer Region Increases Expression of CTSB and Segregates with Keratolytic Winter Erythema in South African and Norwegian Families

Keratolytic winter erythema (KWE) is a rare autosomal-dominant skin disorder characterized by recurrent episodes of palmoplantar erythema and epidermal peeling. KWE was previously mapped to 8p23.1-p22 (KWE critical region) in South African families. Using targeted resequencing of the KWE critical region in five South African families and SNP array and whole-genome sequencing in two Norwegian families, we identified two overlapping tandem duplications of 7.67 kb (South Africans) and 15.93 kb (Norwegians). The duplications segregated with the disease and were located upstream of CTSB, a gene encoding cathepsin B, a cysteine protease involved in keratinocyte homeostasis. Included in the 2.62 kb overlapping region of these duplications is an enhancer element that is active in epidermal keratinocytes. The activity of this enhancer correlated with CTSB expression in normal differentiating keratinocytes and other cell lines, but not with FDFT1 or NEIL2 expression. Gene expression (qPCR) analysis and immunohistochemistry of the palmar epidermis demonstrated significantly increased expression of CTSB, as well as stronger staining of cathepsin B in the stratum granulosum of affected individuals than in that of control individuals. Analysis of higher-order chromatin structure data and RNA polymerase II ChIA-PET data from MCF-7 cells did not suggest remote effects of the enhancer. In conclusion, KWE in South African and Norwegian families is caused by tandem duplications in a non-coding genomic region containing an active enhancer element for CTSB, resulting in upregulation of this gene in affected individuals.

Papillon-Lefèvre syndrome: review of imaging findings and current literature

Papillon-Lefèvre syndrome (PLS) is a rare autosomal recessive condition that causes palmoplantar keratoderma and premature exfoliation of primary and secondary dentition. There are several diseases that can mimic PLS, and it is estimated that the disease is far more prevalent than documented but may either be misdiagnosed or not acknowledged. Radiological exams can provide important clues to differentiate between these syndromes and make an accurate diagnosis.

Connecting with connexins

We describe a case of an 18-year-old woman with congenital sensorineural deafness who presented to the dermatology clinic with asymptomatic thickening of the skin over the palmar aspect of her hands and feet. An examination revealed palmoplantar keratoderma of the palms and soles of the feet with no pseudoainhum. Her father wore a hearing aid and his deafness had been thought to be acquired. Mutation analysis of the connexin 26 gene revealed that she carried a paternally inherited mutation, p.Asp46Glu and a maternally inherited M34T variant. The p.Asp46Glu mutation has been described in a family exhibiting non-syndromic autosomal dominant deafness. Although the M34T variant has been described as a non-pathogenic variant or with a very mild phenotype only, its combination with the p.Asp46Glu mutation may account for her mild cutaneous phenotype with later clinical presentation.

Progressive symmetrical erythrokeratoderma - response to topical calcipotriol

BACKGROUND

Progressive symmetrical erythrokeratoderma is characterized by well-demarcated, symmetrically distributed, erythtematous and hyperkeratotic plaques. Treatment options are topical retinoids, emollients, keratolytics and topical corticosteroids with limited or no success. Oral retinoids have been shown to be successful in some cases, but recurrence is to be expected on cessation of therapy. Topical calcipotriol is an established mode of treatment for psoriasis and also reported to be effective in many hyperkeratotic skin diseases.

MAIN OBSERVATIONS

A 20-year-old female patient presented with reddish-brown lesions in her axillae, groins, submammary regions and on the eyelids. Clinical and histological findings were consistent with the diagnosis of progressive symmetrical erythrokeratoderma. She had noted that her lesions did not improve with topically applied steroids and emollients. We recommended our patient to use topical calcipotriol and observed a remarkable improvement within two weeks.

CONCLUSION

When compared with the other treatment modalities, topical calcipotriol is a safe and effective drug with minimal side effects and it would be a good alternative.

Unilateral aquagenic keratoderma treated with botulinum toxin A

BACKGROUND

Aquagenic keratoderma is a rare transient disease that occurs after water immersion and disappears shortly after drying. Most cases involve the palms and fingers bilaterally but it can also affect the soles. Few cases have been associated with drugs but its pathogenesis remains unclear.

MAIN OBSERVATION

We report a 60-year-old man with a 30-year-history of aquagenic keratoderma of the right palm without associated hyperhidrosis or history of drug intake. After unsuccessful treatment with 15% aluminium chloride hexahydrate gel, botulinum toxin A injections led to significant improvement within 2 weeks.

CONCLUSIONS

To our knowledge, this case is the first report of idiopathic unilateral aquagenic keratoderma in the medical literature. It is the third report of successful treatment with botulinum toxin A which is in favor of a role of sweat glands in the pathogenesis of aquagenic keratoderma.

Papillon-lefevre syndrome

BACKGROUND

Papillon-Lefevre syndrome is a rare autosomal recessive disorder caused by cathepsin C gene mutation leading to the deficiency of cathepsin C enzymatic activity. The disease is characterized by palmoplantar hyperkeratosis, loss of deciduous and permanent teeth and increased susceptibility to infections. Onset of palmoplantar hyperkeratosis and periodontopathy is most commonly before the age of 4 years.

MAIN OBSERVATIONS

A 15 year old boy with a history of frequent infections presented with hyperkeratosis of palms and soles, which worsened during winter season. Examination of the oral cavity revealed missing mandibular central incisors and left lateral incisors. Most remaining permanent teeth were mobile. Fibrosis and scarring of gingival and labial mucosa restricted opening of the mouth.

CONCLUSION

Early diagnosis of Papillon-Lefevre syndrome may help preserve the teeth. We present a case of a late diagnosis of this syndrome.

Genetic disorders of palm skin and nail

The outer part of the skin, the epidermis, is specialized to protect the human body from its environment. Because of the high levels of physical stress experienced by the human hand in everyday use, the epidermis of the hand is especially toughened. In particular, the epidermis of the palm is highly specialized to resist mechanical trauma. Like the epidermis, the nails are composed of specialized epithelial cells and are especially strong. In recent years it has become apparent that the physical strength of epithelial cells comes from the keratin cytoskeleton--a dense meshwork of filaments extending throughout the cytoplasm. Keratins are a large family of intermediate filament proteins encoded by more than 50 distinct genes in humans. These different keratin genes are expressed in well-defined combinations in specific epithelial tissues. Several keratin genes are expressed in palmoplantar epidermis and in the stratified epithelia of the nail bed. Genetic mutations in these genes lead to fragility of these tissues and result in a range of genetic disorders characterized by blistering and thickening of palm and sole skin and/or nails. Study of these diseases has shed new light on the vital structural role of keratins in maintaining the integrity of epithelial cells.