Eur J Hum Genet 2016 Aug 2;24(9):1367-70. Epub 2016 Mar 2.

Department of Dermatology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.

Basan syndrome is a rare autosomal dominant genodermatosis, characterized by rapidly healing congenital acral bullae, congenital milia and lack of fingerprints. A mutation in the SMARCAD1 gene was recently reported to cause Basan syndrome in one family. Here, we present a large Chinese family with Basan syndrome; some patients presented with hyperpigmentation and knuckle pads in addition to previously reported clinical manifestations. Read More

Cutis 2015 Sep;96(3):E10-1

Department of Dermatology, Brown University, 593 Eddy St, APC-10, Providence, RI 02903, USA.

Case Rep Dermatol 2015 May-Aug;7(2):220-6. Epub 2015 Aug 19.

Division of Dermatology, McGill University Health Centre, Montreal, Que., Canada.

Background: Pachyonychia congenita (PC) is a rare autosomal dominant disease whose main clinical features include hypertrophic onychodystrophy and palmoplantar keratoderma. The new classification is based on genetic variants with mutations in keratin KRT6A, KRT6B, KRT6C, KRT16, KRT17, and an unknown mutation. Here, we present a case of PC with unusual clinical and histological features and a favorable response to oral acitretin. Read More

Physiol Rep 2015 Jul 14;3(7). Epub 2015 Jul 14.

Division of Occupational Therapy, Department of Health Professions, Department of Health Sciences and Research, Medical University of South Carolina, Charleston, South Carolina, USA

A recent study showed that fingertip pads' tactile sensation can improve by applying imperceptible white-noise vibration to the skin at the wrist or dorsum of the hand in stroke patients. This study further examined this behavior by investigating the effect of both imperceptible and perceptible white-noise vibration applied to different locations within the distal upper extremity on the fingertip pads' tactile sensation in healthy adults. In 12 healthy adults, white-noise vibration was applied to one of four locations (dorsum hand by the second knuckle, thenar and hypothenar areas, and volar wrist) at one of four intensities (zero, 60%, 80%, and 120% of the sensory threshold for each vibration location), while the fingertip sensation, the smallest vibratory signal that could be perceived on the thumb and index fingertip pads, was assessed. Read More

J Dermatol 2015 Dec 29;42(12):1165-8. Epub 2015 Jun 29.

Department of Dermatology, Medical Faculty, Selcuk University, Konya, Turkey.

Knuckle pads are hyperkeratotic, benign skin lesions that we commonly observe in obese patients. There is no study that investigates the association between metabolic syndrome (MetS) and knuckle pads. We aimed to investigate the frequency of MetS in patients with knuckle pads. Read More

Ned Tijdschr Geneeskd 2015 ;159:A8587

Sint Maartenskliniek, Nijmegen.

A 28-year-old man was referred to our hospital because of localised swelling of his fingers, with suspicion of arthritis of the proximal interphalangeal (PIP) joints. At physical examination we observed a swelling, superficial to the PIP joints. Ultrasonography revealed a hypo-echoic structure above the extensor tendon, typical for knuckle pads. Read More

Pediatr Dermatol 2015 May-Jun;32(3):e126-7. Epub 2015 Mar 17.

Department of Dermatology, University of Toronto, Toronto, Ontario, Canada.

Camptodactyly is a condition characterized by a nontraumatic, fixed flexion contracture at the proximal interphalangeal joint, typically involving the fifth finger. Most occurrences are sporadic, but autosomal dominant transmission and syndromic associations have been described in the literature. We describe the case of an adolescent boy who presented to our clinic with a 2-year history of bilateral, nonsyndromic camptodactyly and knuckle pads. Read More

Am J Hum Genet 2015 Mar 12;96(3):440-7. Epub 2015 Feb 12.

Department of Dermatology, Peking University First Hospital, Beijing 100034, China; Beijing Key Laboratory of Molecular Diagnosis on Dermatoses, Beijing 100034, China; Peking-Tsinghua Center for Life Sciences, Beijing 100871, China. Electronic address:

Calpastatin is an endogenous specific inhibitor of calpain, a calcium-dependent cysteine protease. Here we show that loss-of-function mutations in calpastatin (CAST) are the genetic causes of an autosomal-recessive condition characterized by generalized peeling skin, leukonychia, acral punctate keratoses, cheilitis, and knuckle pads, which we propose to be given the acronym PLACK syndrome. In affected individuals with PLACK syndrome from three families of different ethnicities, we identified homozygous mutations (c. Read More

Ann Dermatol Venereol 2015 Mar 23;142(3):170-5. Epub 2015 Jan 23.

Service de dermatologie, hôpital Saint-Louis, AP-HP, 1, avenue Claude-Vellefaux, 75010 Paris, France. Electronic address:

Background: Ainhum, or spontaneous dactylitis, involves the formation of a gradual constriction in the digital-plantar fold of the fifth toe that leads, after several years, to autoamputation of the digit. This condition is classically distinguished from "true" ainhum, of unknown aetiology and affecting only subjects of African origin, from "pseudo-ainhum", resulting from different causes such as inflammatory constriction or constriction by a foreign body, and finally from ainhumoid palmoplantar keratoderma, which is of genetic origin and occurs for instance in Vohwinkel syndrome. Herein, we report three cases of ainhum in women of sub-Saharan African origin; in addition, all three subjects were also presenting various forms of hyperkeratosis of the hands and feet known to primarily affect subjects of African origin. Read More

Dermatol Online J 2013 May 15;19(5):18177. Epub 2013 May 15.

Warren Alpert Medical School of Brown University Providence, RI, United States.

Knuckle pads are a rare, frequently overlooked, thickening of the skin usually overlying the extensor surface of the proximal interphalangeal joints. They are well- circumscribed, benign lesions that generally do not require treatment. Idiopathic knuckle pads must be differentiated from similar appearing lesions or trauma-induced pseudo-knuckle pads. Read More

Pediatr Dermatol 2013 May-Jun;30(3):354-8. Epub 2012 Dec 26.

Servicio de Genética, Hospital General de México, Facultad de Medicina, Universidad Nacional Autónoma de México, México City, DF, México.

Epidermolytic palmoplantar keratoderma (EPPK), an autosomal-dominant genodermatosis, is the most frequently occurring hereditary palmoplantar keratoderma. EPPK is characterized by hyperkeratosis of the palms and soles. Approximately 90% of patients present with mutations in the KRT9 gene, which encodes for keratin 9. Read More

J Ultrason 2012 Dec 30;12(51):493-8. Epub 2012 Dec 30.

Department of Rheumatology and Musculoskeletal Ultrasound, Bethesda Hospital, Basel, Switzerland.

Knuckle pads are rare harmless subcutaneous nodules that must be differentiated from joint disease of the proximal interphalangeal or rarely of the metacarpophalangeal joints as well as from other masses of the paraarticular tissues. We present a case of an otherwise healthy 36-year-old woman presenting with bilateral knuckle pads located at the dorsal aspect of the proximal interphalangeal joints. No predisposition to a specific musculoskeletal disorder was noted. Read More

MMW Fortschr Med 2012 Nov;154(19):41-2

SportPraxis, Hannover.

Indian J Dermatol 2012 Sep;57(5):390-3

Department of Dermatology and STD, Indira Gandhi Medical College and Research Institute, Pondicherry, India.

Mal de Meleda is a rare autosomal recessive transgradient palmoplantar keratoderma characterized by transgradient keratoderma with associated scleroatrophy, nail changes, pseudoainhum around digits and perioral erythema, without a tendency for spontaneous resolution. Involvement of the lip by keratoderma has not been reported in the English literature. Here we present two cases of Mal de Meleda with unusual lip involvement. Read More

J Hand Surg Am 2012 Oct;37(10):2106-11

Department of Plastic Surgery, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.

Purpose: Dupuytren disease (DD) is a benign fibrosing disorder of the hand and fingers. Recently, we identified 9 single nucleotide polymorphisms (SNPs) associated with DD in a genome-wide association study. These SNPs can be used to calculate a genetic risk score for DD. Read More

J Clin Rheumatol 2012 Aug;18(5):246-8

Rheumatology Department, Hospital de SantaMaria, Centro Hospitalar Lisboa Norte, Lisbon, Portugal.

Pachydermodactyly is a superficial benign fibromatosis of unknown etiology; it is rare, more frequent in adolescent males, and characterized by painless swelling of the proximal interphalangeal joints(PIP) of the hands. Histologic examination of the skin shows epidermal hyperplasia and increased number of dermal fibroblasts and collagen fibers.We report the case of a 16-year-old adolescent boy who presented swelling of the lateral and dorsal regions of all the metacarpophalangeal and PIP joints of the left hand and PIP and metacarpophalangeal joints of the second and fifth fingers of the right hand, with 3 years of evolution and no arthritis or functional impairment. Read More

Indian J Dermatol Venereol Leprol 2012 Mar-Apr;78(2):178-81

2nd Dermatology Clinic, Ankara Numune Education and Research Hospital, Ankara, Turkey.

Bart-Pumphrey syndrome (BPS) is an autosomal-dominant disorder characterized by hearing loss, leukonychia, knuckle pads and palmoplantar keratoderma. Two mutations in the extracellular domain of GBJ2 are resposible for this syndrome. To date, less than 10 case reports or clinical series about BPS have been published in the literature. Read More

Anat Rec (Hoboken) 2012 Apr 20;295(4):604-9. Epub 2012 Jan 20.

Department of Biochemistry and Genetics, National Education Base for Basic Medical Sciences, Institute of Cell Biology, School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China.

Epidermolytic palmoplantar keratoderma (EPPK) is generally associated with dominant-negative mutations of the Keratin 9 gene (KRT9), and rarely with the Keratin 1 gene (KRT1). To date, a myriad of mutations has been reported with a high frequency of codon 163 mutations within the first exon of KRT9 in different populations. Notably, a distinct phenotypic heterogeneity, digital mutilation, was found recently in a 58-year-old female Japanese EPPK patient with p. Read More

Clin Exp Dermatol 2012 Apr 18;37(3):300-1. Epub 2011 Oct 18.

Eur Ann Allergy Clin Immunol 2011 Jun;43(3):95-6

Rheumatology Unit, Hospital of Manerbio (BS), Italy.

Knuckle pads is a syndrome characterized by the presence of multiple nodules located on the extensor side of the interphalangeal or metacarpophalangeal joints. Several conditions can be confused with Knuckle pads. We describe a case of a 47-years-old man who developed multiple bilateral roundish nodules located in the skin over the dorsal and lateral interphalangeal joints in both hands. Read More

Eur J Dermatol 2011 Sep-Oct;21(5):675-9

Department of Biochemistry and Genetics, Zhejiang University, Hangzhou Zhejiang, China.

Knuckle pads and camptodactyly are overlapping symptoms associated with many genetic and environmental factors. To the best of our knowledge, all reported cases of epidermolytic palmoplantar keratoderma (EPPK) with knuckle pads have been without accompanying camptodactyly. We here report a novel KRT9 mutation-EPPK family with combined knuckle pads and camptodactyly. Read More

N Engl J Med 2011 Jun;364(25):2451

Laboratorium für Medizinische Mikrobiologie, Molbis, Germany.

J Hand Surg Am 2011 Jun 12;36(6):1039-41. Epub 2011 Apr 12.

Department of Orthopaedic Surgery, University of Cincinnati College of Medicine, Cincinnati, OH, USA.

A 37-year-old man underwent excision of what was presumed to be knuckle pads associated with Dupuytren disease. The histology revealed granuloma annulare, which is typically treated nonsurgically. This report includes a discussion of granuloma annulare and its differentiation from knuckle pads. Read More

J Dermatol 2012 Jan 5;39(1):84-7. Epub 2011 Apr 5.

Med Hypotheses 2011 May 1;76(5):635-7. Epub 2011 Feb 1.

Plastic, Hand and Reconstructive Surgery, Hannover Medical School, Germany.

Dupuytren's disease is a progressive disease due to unknown causal agents or genetics. An epidemiological analysis of 566 cases in North Germany estimated that around 1.9 million Germans are suffering from Dupuytren's disease. Read More

J Hand Surg Am 2010 Oct;35(10):1571-9

University of Oklahoma Health Sciences Center/INTEGRIS Baptist Medical Center, Oklahoma City, OK 73112, USA.

Purpose: There is ambiguity about using the term "knuckle pads" in Dupuytren's disease (DD). Clear definitions of dorsal knuckle pads and nodules are lacking and the prevalence of these 2 entities has not been determined. We sought to define these terms and investigate the distribution and frequency of dorsal knuckle pads and dorsal nodules in the normal volunteers and in DD patients. Read More

Indian J Dermatol 2010 ;55(1):102-4

Departement of Dermatology, Razi Hospital, Tehran University of Medical Sciences, Tehran, Iran.

A family presented to our dermatology clinic with a complaint of white nails. Physical examination revealed clinical feature of leukonychia totalis and the presence of sensorineural hearing loss, palmo plantar keratoderma and knuckle pads (four essential criteria for the diagnosis of Bart Pumphrey syndrome).Three consecutive generations of this family were affected with variable presentations of Bart Pumphrey syndrome in male and female; and autosomal dominant pattern of inheritance. Read More

Br J Dermatol 2009 Aug 30;161(2):452-5. Epub 2009 Mar 30.

Department of Dermatology, Hokkaido University Graduate School of Medicine, North 15 West 7, Sapporo, Japan.

Background: Connexins, components of the gap junction, are expressed in several organs including the skin and the cochlea. Mutations in connexin genes including GJB2 (Cx26), GJB3 (Cx31), GJB4 (Cx30.3), GJB6 (Cx30) and GJA1 (Cx43) are responsible for various dermatological syndromes and/or inherited hearing loss, frequently showing overlapping phenotypes. Read More

Eur J Dermatol 2009 Mar-Apr;19(2):114-8. Epub 2008 Dec 23.

IDI-IRCCS Biochemistry laboratory c/o Dep. of Experimental Medicine, University of Tor Vergata, Via Montpellier, 1. 00133 Rome, Italy.

Epidermolytic PalmoPlantar keratoderma (EPPK) Vörner-type is an autosomal dominantly inherited skin disease, characterized by severe thickening of the palms and soles, caused by mutations in the keratin K9 (KRT9) gene. To date, a number of KRT9 mutations have been detected, most of which affect the highly conserved 1A region of the central alpha-helical domain, important for keratin heterodimerization. The most common mutation is the substitution of the arginine in position 163 with a tryptophan (R163W), which has been reported in North American, European, and Japanese populations. Read More

J Dermatol 2007 Dec;34(12):838-40

Department of Internal Medicine, Saga Medical School, Saga City, Saga, Japan.

The patient was a 37-year-old male who visited us for the chief complaints of severely keratinized elastic soft nodules with normal skin color or slightly glossy pale brown color at the distal interphalangeal joints of the bilateral second, third, fourth and fifth fingers associated with bilateral clubbed fingers. The nodules were histopathologically diagnosed as knuckle pads. Clubbed fingers were also noted, but no cardiopulmonary disorder was observed. Read More

Arch Dermatol 2007 Nov;143(11):1458-60

Eur J Hum Genet 2008 Feb 14;16(2):265-9. Epub 2007 Nov 14.

Zentrum für Humangenetik, Philipps-Universität Marburg, Bahnhofstr. 7, Marburg, Germany.

Camptodactyly (MIM 114200) is a digit deformity characterised by permanent flexion contracture of fifth fingers at the proximal interphalangeal (PIP) joints. The sporadic cases are common but a familial occurrence is not much appreciated. In an attempt to identify the genetic basis of camptodactyly, we have analysed a large German family with camptodactyly segregating in an autosomal dominant fashion. Read More

Pediatr Ann 2007 Aug;36(8):459-60

Division of Dermatology, Children's Memorial Medical Center, Northwestern University, Chicago, IL, USA.

Proc Inst Mech Eng H 2007 May;221(4):351-6

Institute of Medical Engineering and Medical Physics, Cardiff University, Cardiff, UK.

Fat pads are masses of encapsulated adipose tissue located throughout the human body. Whilst a number of studies describe these soft tissues anatomically little is known about their biomechanics, and surgeons may excise them arthroscopically if they hinder visual inspection of the joint or bursa. By measuring the coefficient of friction between, and performing Sommerfeld analysis of, the surfaces approximating the in vivo conjuncture, this contact has been shown to have a coefficient of friction of the order of 0. Read More

Clin Exp Dermatol 2009 Jan 14;34(1):26-8. Epub 2007 Mar 14.

Departments of Dermatology, Wuxi Second Affiliated Hospital of Nanjing Medical University, Wuxi, Jiangsu, China.

Epidermolytic plamoplantar keratoderma (EPPK) is an autosomal dominant inherited disease. It caused by mutations in the highly conserved coil 1A domain of the keratin 9 gene, KRT9. We studied a four-generation family with EPPK combined with knuckle pads from Jiangsu province, China. Read More

J Invest Dermatol 2007 Jun 25;127(6):1540-3. Epub 2007 Jan 25.

J Dermatol Sci 2007 Jan 30;45(1):63-5. Epub 2006 Oct 30.

Pediatr Dermatol 2006 Sep-Oct;23(5):455-7

Division of Dermatology, Department of Medicine, Medical College of Georgia, Augusta 30904, USA.

Controversy and concern surround the video game playing fascination of children. Scientific reports have explored the negative effects of video games on youth, with a growing number recognizing the actual physical implications of this activity. We offer another reason to discourage children's focus on video games: knuckle pads. Read More

Ned Tijdschr Geneeskd 2006 Sep;150(36):1982

Universitair Medisch Centrum Utrecht, afd. Reumatologie en Klinische Immunologie, F002.127, Postbus 85.500, 3508 GA Utrecht.

A 38-year-old woman with chronic pain of and swelling located at the proximal interphalangeal (PIP) finger joints suffered from 'knuckle pads' or 'Garrod's fatty pads'. Read More

Skeletal Radiol 2006 Nov 11;35(11):823-7. Epub 2006 May 11.

Department of Diagnostic Radiology, The University of Alabama at Birmingham, UAB, N364 JT, 619 19th St S, Birmingham, AL 35294-6830, USA.

Objective: We describe the ultrasound appearance of knuckle pads.

Design And Patients: Retrospective analysis of imaging in a series of five patients initially referred for evaluation of periarticular soft-tissue swelling of the hands involving the dorsum of the PIP and MP joints. Two patients had associated Dupuytren's contractures. Read More

Br J Dermatol 2006 Jan;154(1):167-71

Division of Dermatogenetics, Cologne Centre for Genomics, University of Cologne, Zülpicher Str. 47, 50674 Cologne, Germany.

Loricrin keratoderma is an autosomal dominant palmoplantar keratoderma heterogeneous in clinical appearance. We report a family with diffuse ichthyosis and honeycomb palmoplantar keratoderma but no occurrence of pseudoainhums or autoamputations. All patients were born as collodion babies and displayed prominent knuckle pads. Read More

J Hand Surg Am 2005 Sep;30(5):1014-8

University of Cincinnati College of Medicine, Department of Orthopaedic Surgery, and Hand Surgery Specialists, Cincinnati, OH 45267-0212, USA.

Purpose: To evaluate the progression of Depuytren's nodules with more than 6 years of follow-up study.

Methods: Fifty-nine patients who presented initially with Dupuytren's nodules returned for physical examination at an average follow-up period of 8.7 years (range, 6-15 y). Read More

Am J Surg Pathol 2005 Aug;29(8):1095-105

Department of Soft Tissue Pathology, Armed Forces Institute of Pathology, Washington, DC 20306, USA.

Palmar-plantar fibromatosis, the most common type of fibromatosis, is well recognized in the adult population, but many clinicians and pathologists are unfamiliar with the fact that children may also be affected by this process. This report describes the clinicopathologic findings in 56 cases of palmar-plantar fibromatosis in children and preadolescents. Our study group included 19 males and 37 females, ranging from 2 to 12 years of age at the time of their first surgical procedure (median age, 9 years). Read More

J Med Genet 2005 Jan;42(1):e2

Department of Medical Genetics, 8-53 Medical Sciences Building, University of Alberta Hospital, Edmonton, Alberta, Canada T6G 2H7.

Chir Main 2004 Aug;23(4):205-7

Hôpital américain de Neuilly, 92200 Neuilly-sur-Seine, France.

Pachydermodactyly is a superficial benign, symmetrical and painless fibromatosis, characterized by a swelling of the proximal interphalangeal joints of the fingers. Histological examination shows epidermal hyperplasia increase of dermal collagen bundles and an increased number of fibroblasts. We report two cases of pachydermodactyly in male teenagers. Read More

J Invest Dermatol 2004 Nov;123(5):856-63

Department of Dermatology and Cutaneous Biology, and Jefferson Institute of Molecular Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania, USA.

Bart-Pumphrey syndrome (BPS) is an autosomal dominant disorder characterized by sensorineural hearing loss, palmoplantar keratoderma, knuckle pads, and leukonychia, which show considerable phenotypic variability. The clinical features partially overlap with Vohwinkel syndrome and Keratitis-Ichthyosis-Deafness syndrome, both disorders caused by dominant mutations in the GJB2 gene encoding the gap junction protein connexin-26, suggesting an etiological relationship. We report here a novel GJB2 mutation N54K segregating in a family with BPS, which was not detected in 110 control individuals of Northern European ancestry. Read More

Turk J Pediatr 2003 Oct-Dec;45(4):348-9

Department of Dermatology, Fatih University, Faculty of Medicine, Ankara, Turkey.

Knuckle pads are discrete benign cutaneous lesions overlying the extensor surfaces of the fingers and hand joints and are unrelated to trauma, whereas pseudo-knuckle pads may be considered as a form of callosity that appears after repeated trauma. This type of knuckle pad has been described in children with obsessive behavior as "chewing pads" and in adults as occupational disorder. Cases of pachydermodactyly, benign fibromatosis of the fingers, have been described as the unusual forms of knuckle pads that usually affect young adult males. Read More

Am J Med Genet A 2003 Jul;120A(3):345-9

Research Institute of Medical Genetics, School of Medicine, Shandong University, Jinan Shandong, People's Republic of China.

Epidermolytic palmoplantar keratoderma (EPPK) is an autosomal dominantly inherited disease. We studied a family from Shandong, China, having patients suffering from EPPK with a unique symptom-knuckle pads. We noticed that both the hyperkeratosis and knuckle pads in the Chinese family were friction-related. Read More

Australas J Dermatol 2003 May;44(2):140-3

Department of Dermatology, The Churchill, Oxford Radcliffe Hospitals, UK.

A 16-year-old boy presented with painless swellings localized to the radial and ulnar aspects of his second through to the fifth fingers on the left hand, with more subtle changes affecting two fingers on the opposite hand. This had developed in the absence of mechanical trauma. Investigations for an arthropathy were negative, while a biopsy showed marked epidermal hyperplasia and an expanded dermis. Read More

Int J Dermatol 2002 May;41(5):291-3

Department of Dermatology, College of Medicine, University of Cincinnati, Ohio 45267-0592, USA.

Knuckle pads, first described by Garrod in 1893, 1 are benign, asymptomatic, well- circumscribed, smooth, firm, skin colored papules, nodules, or plaques. They most commonly occur on the dorsal aspect of the proximal interphalangeal joint of the finger, 2 but also may occur on the dorsal aspects of the foot over joints. 3-5 Knuckle pads may be inherited or acquired. Read More