RESUMO
BACKGROUND: Congenital erosive and vesicular dermatosis (CEVD) healing with reticulated supple scarring, a condition usually observed in premature neonates, presents at birth with vesicles and erosions. Lesions typically heal within a few months, leaving behind scarring with a distinctive supple and reticulated texture. OBJECTIVES: We sought to merge existing literature with new cases to further define CEVD. METHODS: We analyzed 19 previous reports of CEVD and added 9 additional patients; we identified unifying characteristics of this cohort. RESULTS: In 28 total cases, notable features included: preterm birth (79%), nail abnormalities (46%), hyperthermia/hypohidrosis (46%), a history of maternal chorioamnionitis (43%), alopecia (43%), neurodevelopmental and ophthalmologic abnormalities (36% each), tongue atrophy (29%), or a combination of these. Patients with CEVD may be prone to postnatal herpetic superinfections. Previously unreported findings included: erosive lichen planus, digital tip gangrene, and hydronephrosis. LIMITATIONS: The small patient sampling makes it difficult to define diagnostic criteria. As certain findings are associated with prematurity, it is unclear to what extent these features result from CEVD, premature birth, or another intrauterine pathology. CONCLUSIONS: Although rare, CEVD should be considered in the differential diagnosis of neonatal vesicles/erosions in the context of a negative infectious workup. This review strengthens the spectrum of CEVD features, thus facilitating its recognition by clinicians.
Assuntos
Cicatriz/etiologia , Dermatopatias Vesiculobolhosas/congênito , Dermatopatias Vesiculobolhosas/complicações , Humanos , Lactente , Recém-NascidoRESUMO
Kasabach-Merritt phenomenon (KMP) is a rare consumptive coagulopathy characterized by profound thrombocytopenia and hypofibrinogenemia occurring in association with the vascular tumors kaposiform hemangioendothelioma (KHE) and tufted angioma (TA). Treatment remains challenging without consensus on the optimal medical management. The authors compiled expert opinions regarding management to establish treatment recommendations. Twenty-seven vascular anomalies centers in the United States and Canada were surveyed using 2 representative cases of KHE/TA with and without KMP. Overall response rate was 92% (25/27) with 88% completion (24/27). Most sites (23/25; 92%) do not have a standard of practice for management. The most frequent initial therapy for KHE+KMP was a combination of systemic corticosteroids and vincristine (VCR) (12/24 centers; 50%) followed by corticosteroids alone (29%). Second-line treatments were VCR (38%), rapamycin (21%), and propranolol (21%). Management of KHE/TA without KMP was variable; initial treatments included systemic corticosteroids (8/24; 33%) alone or with VCR (9/24; 38%), monitoring without medication (33%), VCR (8%), propranolol (8%), aspirin (4%), and rapamycin (4%). This survey highlights certain trends in the management of KMP-associated tumors, without standard protocols and consensus.
Assuntos
Hemangioendotelioma/tratamento farmacológico , Hemangioma/tratamento farmacológico , Síndrome de Kasabach-Merritt/tratamento farmacológico , Padrões de Prática Médica/estatística & dados numéricos , Sarcoma de Kaposi/tratamento farmacológico , Neoplasias Cutâneas/tratamento farmacológico , Corticosteroides/uso terapêutico , Antineoplásicos/uso terapêutico , Coleta de Dados , Hemangioendotelioma/etiologia , Hemangioma/etiologia , Humanos , Síndrome de Kasabach-Merritt/complicações , Síndrome de Kasabach-Merritt/etiologia , Propranolol/uso terapêutico , Sarcoma de Kaposi/etiologia , Neoplasias Cutâneas/etiologia , Vasodilatadores/uso terapêutico , Vincristina/uso terapêuticoRESUMO
A six-week-old girl presented with a segmental, focally atrophic, vascular patch in the diaper area, present since birth. It had undergone minimal proliferation, but had ulcerated. Evaluation to rule out LUMBAR (Lower body hemangioma/Lipoma or other cutaneous anomalies, Urogenital anomalies, Myelopathy, Bony deformities, Anorectal/Arterial anomalies, and Renal anomalies) syndrome, which included ultrasound and Doppler examination of the abdomen, spine, and pelvis, was negative. We report a unique case of an ulcerated, segmental abortive hemangioma of the anogenital area with excellent clinical response to topical timolol gel.
Assuntos
Hemangioma/congênito , Períneo/patologia , Neoplasias Cutâneas/congênito , Administração Cutânea , Antagonistas Adrenérgicos beta/administração & dosagem , Antagonistas Adrenérgicos beta/uso terapêutico , Biomarcadores Tumorais/análise , Feminino , Transportador de Glucose Tipo 1/análise , Hemangioma/química , Hemangioma/complicações , Hemangioma/tratamento farmacológico , Hemangioma/patologia , Humanos , Lactente , Neoplasias Cutâneas/química , Neoplasias Cutâneas/complicações , Neoplasias Cutâneas/tratamento farmacológico , Neoplasias Cutâneas/patologia , Úlcera Cutânea/etiologia , Timolol/administração & dosagem , Timolol/uso terapêuticoRESUMO
A healthy 25-year-old man presented with a widespread, non-organoid, non-epidermolytic epidermal nevus. In addition to extensive hyperpigented patches and thin plaques following Blaschko lines, there were superimposed psoriasiform plaques on the elbows and warty plaques on the upper trunk. Striate palmar keraoderma also was evident. We review the clinical morphologies, sites of involvement, histopathologic findings (presence or absence of epidermolytic hyperkeratosis), and syndromal associations of non-organoid EN with underlying mutations in different genes.
Assuntos
Ceratodermia Palmar e Plantar/diagnóstico , Nevo/diagnóstico , Neoplasias Cutâneas/diagnóstico , Adulto , Diagnóstico Diferencial , Hamartoma/diagnóstico , Hamartoma/patologia , Humanos , Hiperpigmentação/diagnóstico , Hiperpigmentação/patologia , Ceratodermia Palmar e Plantar/patologia , Masculino , Nevo/patologia , Nevo Sebáceo de Jadassohn/diagnóstico , Nevo Sebáceo de Jadassohn/patologia , Neoplasias Cutâneas/patologiaRESUMO
A 39-year-old Hispanic man presented with widespread, symmetric, hyperpigmented, brown-gray-blue, oval-to-circular, discrete and coalescing patches on the upper extremities, trunk, neck and face, many with an associated annular erythematous border. Histopathologic features showed an interface dermatitis, thin lichenoid and superficial perivascular infiltrates, and dermal melanophages. These changes were consistent with a diagnosis of erythema dyschromicum perstans (EDP). The etiology of EDP is unknown, but many associations have been described. The rim of erythema that appears during the inflammatory phase of the disorder distinguishes it from other disorders of hyperpigmentation. There is no consistently effective treatment for EDP. We highlight the use of narrow-band UV B phototherapy in the treatment of this disorder, which has shown good success in our patient thus far.
Assuntos
Eritema/diagnóstico , Eritema/radioterapia , Hiperpigmentação/radioterapia , Terapia Ultravioleta , Adulto , Braço/patologia , Eritema/patologia , Humanos , Hiperpigmentação/patologia , MasculinoRESUMO
Sporotrichosis is caused by the dimorphic fungus, Sporothrix schenckii. Classically, infection occurs after implantation of the organism into the skin by abrasion of a puncture wound by contaminated thorns, hay, or sphagnum moss. Cats are also a commonly recognized source of sporotrichosis. In children, fixed cutaneous lesions are more common than lymphocutaneous lesions, and the face is a frequent location for infection. We present a neonate with a fixed cutaneous facial lesion and both pre-auricular and cervical lymphadenopathy who developed signs of infection at 3 weeks of age. This patient is currently the youngest reported case of sporotrichosis in the literature. The patient's family denied any trauma and denied contact with flowers, gardens, and cats; thus, the source of infection remains unknown.
Assuntos
Anfotericina B/administração & dosagem , Antifúngicos/administração & dosagem , Sporothrix/isolamento & purificação , Esporotricose/diagnóstico , Esporotricose/tratamento farmacológico , Antibacterianos/administração & dosagem , Ceftriaxona/administração & dosagem , Testa , Humanos , Lactente , Masculino , Infecções por Serratia/diagnóstico , Infecções por Serratia/tratamento farmacológico , Serratia marcescens , Esporotricose/microbiologia , Superinfecção/diagnóstico , Superinfecção/tratamento farmacológico , Superinfecção/microbiologiaRESUMO
A growing body of literature has identified the association between neutrophilic dermatoses and multifocal, aseptic bone lesions in children, termed chronic recurrent multifocal osteomyelitis (CRMO). Classically, patients present with swelling, pain, and impaired mobility of the affected area, with skin lesions developing concurrently or in the future. Bone biopsy reveals inflammatory changes consistent with infectious osteomyelitis, but cultures and histologic staining invariably fail to identify an infectious source. Patients are refractory to antibiotic therapy, but dramatically respond to systemic steroids and may need to be maintained on low-dose steroids to prevent relapse. Numerous authors have suggested that CRMO and synovitis, acne, pustulosis, hyperostosis, osteitis (SAPHO) syndrome lie along the same clinical spectrum. In fact some believe that CRMO is the pediatric presentation of SAPHO. The two syndromes share numerous characteristics, including osteitis, a unifocal or multifocal presentation, hyperostosis, and pustulosis, which all occur in a generally healthy individual. Our seven patients, five of whom were diagnosed with CRMO, and two of whom were diagnosed with SAPHO syndrome further strengthen the idea that CRMO and SAPHO syndrome do indeed lie along the same clinical spectrum. In addition, we include two rare cases of pediatric Sweet's syndrome with evidence of pathergy.
Assuntos
Síndrome de Hiperostose Adquirida/complicações , Síndrome de Hiperostose Adquirida/patologia , Osteomielite/complicações , Osteomielite/patologia , Pele/patologia , Síndrome de Hiperostose Adquirida/tratamento farmacológico , Adolescente , Criança , Pré-Escolar , Doença Crônica , Feminino , Humanos , Masculino , Osteomielite/tratamento farmacológico , Recidiva , Esteroides/uso terapêuticoRESUMO
A 21-year-old man presented with a life-long history of diffusely thickened skin with a grainy-to-ridged surface, verrucous perioral plaques with radial fissures, and diffuse palmoplantar keratoderma with a stippled appearance. These skin findings were accompanied by sensorineural hearing loss and keratoconjunctivitis, a clinical triad diagnostic of keratitis-ichthyosis-deafness (KID) syndrome. The patient also had a history of recurrent infections and cysts on the scalp. This report draws attention to inflammatory nodules (representing ruptured folliculitis), cysts, and recurrent infections on the scalp as manifestations of KID syndrome and reviews the increasingly recognized risk of follicular tumors and squamous-cell carcinomas in patients with this conditions.
Assuntos
Surdez , Ictiose , Ceratite , Humanos , Ictiose/patologia , Ceratite/patologia , Masculino , Síndrome , Adulto JovemRESUMO
IMPORTANCE: Controversy exists regarding strategies for diagnosis and management of Spitz nevi, a type of melanocytic neoplasm that most often develops in children. OBJECTIVE: To determine the beliefs, behaviors, and experiences of pediatric dermatologists with regard to Spitz nevi. DESIGN: Anonymous web-based survey. SETTING: Private and academic dermatology practices. PARTICIPANTS: Respondents included 175 pediatric dermatologists from the United States and around the world, representing a 51.1% response rate (175 of 342). Analyses were limited to the 144 respondents whose practices included at least 50% children (younger than 18 years). MAIN OUTCOME MEASURES: Assessment of the following with regard to Spitz nevi: frequency of diagnosis, general beliefs, techniques used for evaluation (eg, dermoscopy and biopsy), management strategies, and observed outcomes. RESULTS: Collectively, respondents had seen approximately 20 000 Spitz nevi; 67.6% (96 of 142) had diagnosed at least 6 Spitz nevi yearly, whereas 90.1% (128 of 142) had diagnosed no more than 2 prepubertal melanomas in the past 5 years. Ninety-six percent of respondents (95.8%; 136 of 142) categorized typical Spitz nevi as benign. Eighty percent of respondents (79.6%; 113 of 142) used dermatoscopy, and 96.5% (137 of 142) avoided partial biopsies of Spitz nevi. In children with a suspected Spitz nevus, clinical follow-up was chosen by 49.3% (69 of 140) of respondents for a small, stable nonpigmented lesion and by 29.7% (41 of 138) for a pigmented lesion with a typical starburst pattern seen via dermatoscopy. Predictors of clinical follow-up of the latter lesion included believing that Spitz nevi are not melanoma precursors (P = .04). Forty-seven percent (62 of 132) of respondents had observed involution of Spitz nevi. No deaths had resulted from the approximately 10 000 Spitz nevi or atypical spitzoid neoplasms seen by the 91 respondents with academic or hospital-based practices. CONCLUSIONS AND RELEVANCE: The results of our survey support conservative management of Spitz nevi in children, with clinical follow-up representing an option for typical lesions. This represents an important difference from strategies used for management of these lesions in adults.
Assuntos
Atitude do Pessoal de Saúde , Nevo de Células Epitelioides e Fusiformes/terapia , Padrões de Prática Médica/estatística & dados numéricos , Neoplasias Cutâneas/terapia , Adolescente , Criança , Dermatologia/estatística & dados numéricos , Pesquisas sobre Atenção à Saúde , Humanos , Nevo de Células Epitelioides e Fusiformes/diagnóstico , Avaliação de Resultados em Cuidados de Saúde , Pediatria/estatística & dados numéricos , Neoplasias Cutâneas/diagnósticoRESUMO
Each year in the United States over 80 million people participate in bat-and-ball sports, for example baseball and softball. Cricket, the world's second most popular sport, is enjoyed by hundreds of millions of participants in such countries as India, Pakistan, Australia, New Zealand, Bangladesh, South Africa, West Indies, Sri Lanka, United Kingdom, and Zimbabwe. Although any player can develop skin disease as a result of participation in these bat-and-ball sports, competitive team athletes are especially prone to skin problems related to infection, trauma, allergy, solar exposure, and other causes. These diseases can produce symptoms that hinder individual athletic performance and participation. In this review, we discuss the diagnosis and best-practice management of skin diseases that can develop as a result of participation in baseball, softball, and cricket.
Assuntos
Beisebol , Dermatopatias/etiologia , Anabolizantes/efeitos adversos , Androgênios/efeitos adversos , Beisebol/lesões , Contusões/diagnóstico , Contusões/etiologia , Contusões/terapia , Dermatite de Contato/diagnóstico , Dermatite de Contato/etiologia , Dermatite de Contato/terapia , Toxidermias/diagnóstico , Toxidermias/etiologia , Toxidermias/terapia , Humanos , Púrpura/diagnóstico , Púrpura/etiologia , Púrpura/terapia , Dermatopatias/diagnóstico , Dermatopatias/terapia , Dermatopatias Infecciosas/diagnóstico , Dermatopatias Infecciosas/etiologia , Dermatopatias Infecciosas/terapia , Esteroides/efeitos adversos , Queimadura Solar/diagnóstico , Queimadura Solar/etiologia , Queimadura Solar/terapiaRESUMO
Figure skaters, ice-hockey players and speed skaters experience a range of dermatologic conditions and tissue-related injuries on account of mechanical trauma, infectious pathogens, inflammatory processes and environmental factors related to these competitive pursuits. Sports medicine practitioners, family physicians, dermatologists and coaches should be familiar with these skin conditions to ensure timely and accurate diagnosis and management of affected athletes. This review is Part I of a subsequent companion review and provides a comprehensive review of mechanical dermatoses experienced by ice-skating athletes, including skater's nodules and its variants, pump bumps, piezogenic pedal papules, talon noir, skate/lace bite, friction bullae, corns and calluses, onychocryptosis, skater's toe and skate blade-induced lacerations. These injuries result from friction, shear forces, chronic pressure and collisions with surfaces that occur when athletes endure repetitive jump landings, accelerated starts and stops and other manoeuvres during rigorous training and competition. Ill-fitting skates, improper lacing techniques and insufficient lubrication or protective padding of the foot and ankle often contribute to the development of skin conditions that result from these physical and mechanical stresses. As we will explain, simple measures can frequently prevent the development of these conditions. The treatment of skater's nodules involves reduction in chronic stimulation of the malleoli, and the use of keratolytics and intralesional steroid injections; if malleolar bursitis develops, bursa aspirations may be required. Pump bumps, which result from repetitive friction posteriorly, can be prevented by wearing skates that fit correctly at the heel. Piezogenic pedal papules may be treated conservatively by using heel cups, compressive stockings and by reducing prolonged standing. Talon noir usually resolves without intervention within several weeks. The treatment of skate bite is centred on reducing compression by the skate tongue of the extensor tendons of the anterior ankle, which can be accomplished by use of proper lacing techniques, increasing pliability of the skate tongue and using protective padding, such as Bunga Pads™. Anti-inflammatory medications and cold compresses can also help reduce inflammation. Friction bullae are best managed by careful lancing of painful blisters and application of petrolatum or protective dressings to accelerate healing; preventative measures include the use of well fitting skates, proper lacing techniques and moisture-wicking socks. Corns and calluses are similarly best prevented by the use of well fitted skates and orthotic devices. Symptomatic, debridement reduces the irritant effect of the thick epidermis, and can be accomplished by soaking the area in warm water followed by paring. Application of creams with high concentrations of urea or salicylic acid can also soften callosities. Cases of onychocryptosis benefit from warm soaks, antibiotic ointments and topical steroids to reduce inflammation, but sometimes chemical or surgical matricectomies are required. Preventative measures of both onychocryptosis and skater's toe include cutting toenails straight across to allow for a more equal distribution of forces within the toe box. Finally, the prevention and treatment of lacerations, which constitute a potentially fatal type of mechanical injury, require special protective gear and acute surgical intervention with appropriate suturing. The subsequent companion review of skin conditions in ice skaters will discuss infectious, inflammatory and cold-induced dermatoses, with continued emphasis on clinical presentation, diagnosis, treatment and prevention.
Assuntos
Hóquei/lesões , Patinação/lesões , Dermatopatias/diagnóstico , Dermatopatias/terapia , Atletas , Calosidades/diagnóstico , Calosidades/etiologia , Calosidades/terapia , Feminino , Humanos , Lacerações/diagnóstico , Lacerações/etiologia , Lacerações/terapia , Masculino , Dermatopatias/etiologia , Estresse MecânicoRESUMO
Participation in ice-skating sports, particularly figure skating, ice hockey and speed skating, has increased in recent years. Competitive athletes in these sports experience a range of dermatological injuries related to mechanical factors: exposure to cold temperatures, infectious agents and inflammation. Part I of this two part review discussed the mechanical dermatoses affecting ice-skating athletes that result from friction, pressure, and chronic irritation related to athletic equipment and contact with surfaces. Here, in Part II, we review the cold-induced, infectious and inflammatory skin conditions observed in ice-skating athletes. Cold-induced dermatoses experienced by ice-skating athletes result from specific physiological effects of cold exposure on the skin. These conditions include physiological livedo reticularis, chilblains (pernio), Raynaud phenomenon, cold panniculitis, frostnip and frostbite. Frostbite, that is the literal freezing of tissue, occurs with specific symptoms that progress in a stepwise fashion, starting with frostnip. Treatment involves gradual forms of rewarming and the use of friction massages and pain medications as needed. Calcium channel blockers, including nifedipine, are the mainstay of pharmacological therapy for the major nonfreezing cold-induced dermatoses including chilblains and Raynaud phenomenon. Raynaud phenomenon, a vasculopathy involving recurrent vasospasm of the fingers and toes in response to cold, is especially common in figure skaters. Protective clothing and insulation, avoidance of smoking and vasoconstrictive medications, maintaining a dry environment around the skin, cold avoidance when possible as well as certain physical manoeuvres that promote vasodilation are useful preventative measures. Infectious conditions most often seen in ice-skating athletes include tinea pedis, onychomycosis, pitted keratolysis, warts and folliculitis. Awareness, prompt treatment and the use of preventative measures are particularly important in managing such dermatoses that are easily spread from person to person in training facilities. The use of well ventilated footgear and synthetic substances to keep feet dry, as well as wearing sandals in shared facilities and maintaining good personal hygiene are very helpful in preventing transmission. Inflammatory conditions that may be seen in ice-skating athletes include allergic contact dermatitis, palmoplantar eccrine hidradenitis, exercise-induced purpuric eruptions and urticaria. Several materials commonly used in ice hockey and figure skating cause contact dermatitis. Identification of the allergen is essential and patch testing may be required. Exercise-induced purpuric eruptions often occur after exercise, are rarely indicative of a chronic venous disorder or other haematological abnormality and the lesions typically resolve spontaneously. The subtypes of urticaria most commonly seen in athletes are acute forms induced by physical stimuli, such as exercise, temperature, sunlight, water or particular levels of external pressure. Cholinergic urticaria is the most common type of physical urticaria seen in athletes aged 30 years and under. Occasionally, skaters may develop eating disorders and other related behaviours some of which have skin manifestations that are discussed herein. We hope that this comprehensive review will aid sports medicine practitioners, dermatologists and other physicians in the diagnosis and treatment of these dermatoses.
Assuntos
Temperatura Baixa , Hóquei/lesões , Patinação/lesões , Dermatopatias/etiologia , Deficiências Nutricionais/complicações , Transtornos da Alimentação e da Ingestão de Alimentos/complicações , Humanos , Dermatopatias/diagnóstico , Dermatopatias/terapia , Dermatopatias Infecciosas/etiologia , Equipamentos Esportivos , Medicina EsportivaRESUMO
The first of this three-part series on water-related dermatoses involving the athlete will include sports occurring with the majority of time spent in the water. These sports include swimming, diving, scuba, snorkeling and water polo. Numerous authors have described dermatologic conditions commonly seen in swimmers. This series provides an updated and comprehensive review of these water dermatoses. In order to organize the vast number of skin conditions related to water exposure, we divided the skin conditions into groupings of infectious and organism-related dermatoses, irritant and allergic dermatoses and miscellaneous dermatoses. The vast majority of skin conditions involving the water athlete result from chemicals and microbes inhabiting each environment. When considering the effects of swimming on one's skin, it is also useful to differentiate between exposure to freshwater (lakes, ponds and swimming pools) and exposure to saltwater. This review will serve as a guide for dermatologists, sports medicine physicians and other medical practitioners in recognition and treatment of these conditions.
Assuntos
Mergulho/efeitos adversos , Água Doce , Dermatopatias , Medicina Esportiva , Humanos , Dermatopatias/diagnóstico , Dermatopatias/etiologia , Dermatopatias/terapia , PiscinasRESUMO
The second part of this three-part series on water-related dermatoses will discuss dermatologic conditions seen in athletes exposed to saltwater. The vast majority of the following dermatoses result from contact with organisms that inhabit saltwater, including bacteria, cnidarians, and echinoderms. This review also will include other dermatoses affecting saltwater athletes and should serve as a guide for dermatologists, sports medicine physicians, and other medical practitioners in recognition and treatment of these dermatoses.
Assuntos
Traumatismos em Atletas/patologia , Traumatismos em Atletas/terapia , Água do Mar , Dermatopatias/patologia , Dermatopatias/terapia , Natação , Animais , Traumatismos em Atletas/etiologia , Doença da Descompressão/etiologia , Doença da Descompressão/patologia , Doença da Descompressão/terapia , Feminino , Humanos , Masculino , Água do Mar/efeitos adversos , Água do Mar/microbiologia , Água do Mar/parasitologia , Dermatopatias/etiologiaRESUMO
The third of this three-part series on water-related sports dermatoses discusses skin changes seen in athletes who participate in sporting activities on top of or nearby water. While also susceptible to several of the freshwater and saltwater dermatoses discussed in parts one and two of the series, these athletes may present with skin changes unique to their particular sports. This updated and comprehensive review details those near-water dermatologic conditions commonly seen in sailors, rowers, fishermen, surfers, windsurfers, rafters, and water skiers, and will serve as a guide for dermatologists, sports medicine physicians and other medical practitioners in recognition and treatment of these conditions.
Assuntos
Dermatopatias/diagnóstico , Dermatopatias/etiologia , Esportes , Microbiologia da Água , Água , Corticosteroides/uso terapêutico , Animais , Temperatura Baixa/efeitos adversos , Infecções por Erysipelothrix/diagnóstico , Infecções por Erysipelothrix/etiologia , Infecções por Erysipelothrix/terapia , Peixes , Antagonistas dos Receptores Histamínicos/uso terapêutico , Humanos , Doenças Profissionais/diagnóstico , Doenças Profissionais/etiologia , Doenças Profissionais/terapia , Penicilinas/uso terapêutico , Borracha/efeitos adversos , Dermatopatias/terapiaRESUMO
Despite their rarity, diseases of premature aging, or "progeroid" syndromes, have provided important insights into basic mechanisms that may underlie cancer and normal aging. In this review, we highlight these recent developments in Hutchinson-Gilford progeria syndrome (HGPS), Werner syndrome, Bloom syndrome, Cockayne syndrome, trichothiodystrophy, ataxia-telangiectasia, Rothmund-Thomson syndrome, and xeroderma pigmentosum. Though they are caused by different mutations in various genes and often result in quite disparate phenotypes, deciphering the molecular bases of these conditions has served to highlight their underlying basic similarities. Studies of progeroid syndromes, particularly HGPS, the most dramatic form of premature aging, have contributed to our knowledge of fundamental processes of importance to skin biology, including DNA transcription, replication, and repair, genome instability, cellular senescence, and stem-cell differentiation.