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A 7-year-old girl presented with a 2-year history of recurrent blisters on the skin and oral mucosa. The patient was otherwise healthy, and her family history was unremarkable for any dermatologic or other medical disease. Examination revealed multiple tense vesicles, milia, and atrophic scars present over the extensor surface of the extremities and erosions on the oral mucosa (Figure 1). A skin biopsy established a pauci-inflammatory subepidermal blister (Figure 2a). Direct immunofluorescence (DIF) evidenced the linear deposition of immunoglobulin G (IgG), immunoglobulin M (IgM), and κ and λ chains at the dermal-epithelial junction (DEJ). Indirect immunofluorescence (IIF), using the salt-split technique, established anti-epithelial antibodies on the dermal side (Figure 2b). An enzyme-linked immunosorbent assay (ELISA) was positive for Collagen Type VII (COL7) antibodies. A diagnosis of epidermolysis bullosa acquisita (EBA) was made, and treatment with azathioprine and deflazacort was administered for 8 months with progressive lessening of her symptomatology and complete clinical response at 2-year follow-up. (

BACKGROUND/OBJECTIVES Acute graft-versus-host disease (aGVHD) is a serious condition after allogeneic hematopoietic stem cell transplantation (HSCT), frequently involving skin, gut, and liver. It can be difficult to diagnose early, yet this is vital for adequate management. We sought to identify initial clinical and histopathological features in children with suspected GVHD and the association with clinical course and outcomes. METHODS Retrospective study of patients with skin biopsies for suspected aGVHD from 2006 to 2016. We collected demographic and clinical information, histologic, and immunohistochemical (IHC) findings, and outcomes during follow-up. Bivariate and multivariate analyses were done to identify risk factors associated with remission, development of severe/life-threatening aGVHD, and mortality. RESULTS We included 42 patients, 15 females. Skin manifestations occurred 51 days (median) after HSCT. On biopsy, 76.2% had mild (stage 1-2) skin aGVHD; during the course of the disease, severity and systemic involvement increased to global grade III/IV in 66.6%. All patients received treatment; 15 are in remission from aGVHD and 23 have died. Histologic features were diagnostic in 83.3%. On bivariate and multivariate analysis, we identified initial clinical and histologic findings that were associated with the measured outcomes: odds of remission from aGVHD were increased when focal vacuolar changes were found on skin biopsy (OR 6.028; 95%CI:1.253-28.992) but decreased by initial hepatic aGVHD (OR 0.112; 95%CI: 0.017-0.748); severe/life-threatening aGVHD was associated with initial gastrointestinal aGVHD (OR 6.054; 95%CI:1.257-29.159); and odds of mortality were decreased with male donor (OR 0.056; 95%CI:0.004-0.804), nulliparous female donor (OR 0.076; 95%CI:0.009-0.669), and focal vacuolar changes on skin biopsy (OR 0.113; 95%CI:0.017-0.770). CONCLUSIONS We found novel indicators predictive of remission, severity, and mortality in children with aGVHD. Further studies of this condition in children are needed.

Paraneoplastic pemphigus is a rare and severe autoimmune blistering disease characterized by a recalcitrant and severe mucositis, and polymorphic cutaneous lesions, associated with benign and malignant neoplasms. Paraneoplastic pemphigus is caused by production of autoantibodies against various epidermal proteins involved in cell adhesion. Bronchiolitis obliterans (BO) is one of the leading causes of mortality in these patients. Recent advances have associated the presence of anti-epiplakin antibodies with the development of BO in adult patients. Here we describe the first pediatric patient in whom the association of anti-epiplakin antibodies and BO have been reported so far.

Menkes disease (MD) is a rare X-linked recessive neurodegenerative disorder caused by mutations in the ATP7A gene, with a high mortality rate within the first 3 years of life. It typically affects males and is characterized by impaired copper distribution and malfunction of several copper-dependent enzymes. Patients develop progressive muscle hypotonia associated with neurological damage and hair shaft dysplasia – particularly pili torti. Pili torti is usually very subtle in the first 3 months of life and gradually increases during the first year. Light microscopy examination in search for pili torti requires the observation of more than 50 hair shafts. In contrast, trichoscopy with a hand-held dermatoscope allows to easily identify the hair shaft defect. We report a case of a Hispanic male infant with MD in whom we show that trichoscopy is superior to hair light microscopy in revealing pili torti.

Background Autoinflammation and phospholipase Cγ2-associated antibody deficiency and immune dysregulation (APLAID) is an exceedingly rare monogenic autoinflammatory disease. To date, only five cases have been reported with four distinct pathogenic mutations. Objectives We present a novel case of APLAID, corroborated by molecular analysis, with newly described clinical findings including central nervous system vasculitis (CNSV); and distinctive histopathological characteristics that may expand our knowledge of this rare disease's phenotype. Methods This is a case report presentation of a 3-year-old boy, seen at a reference paediatric hospital in Mexico. His parents authorized the use of his clinical information and photographs. Results A 3-day-old boy presented to the emergency department with a vesiculo-pustular rash that resolved within 1 week. Two months later, he developed widespread papules and pseudovesicles that evolved into infiltrated plaques. He also had periodical flares of conjunctivitis, diarrhoea and erythematous blistering acral plaques triggered by upper respiratory infections. By the age of 10 months, he experienced seizures and CNSV. Laboratory work-up showed mild neutropenia, decreased serum levels of immunoglobulins and B-cell lymphopenia. A skin biopsy revealed a dense, perivascular and interstitial histiocytic and granulomatous infiltrate, with palisading granulomas, and leucocytoclastic vasculitis with karyorrhexis. APLAID syndrome was confirmed by Sanger sequencing of PLCG2 gene [heterozygous genotype LRG_376t1:c.2543T>C or p.(Leu848Pro)]. Conclusions Presence of CNSV has not been previously described in APLAID, however as the number of reported patients with APLAID is very small, it is possible that the overall spectrum of clinical manifestations has not been completely elucidated. The herein identified p.(Leu848Pro) variant was also documented in a Portuguese patient, suggesting that it could be a PLCG2 gene 'hot-spot'.

Background Kawasaki disease (KD) is an acute systemic vasculitis that predominantly affects patients younger than 5 years. In the absence of an available, affordable diagnostic test, detailed clinical history and physical examination are still fundamental to make a diagnosis. Methods We present five representative cases with KD-like presentations: systemic onset juvenile idiopathic arthritis, mycoplasma-induced rash and mucositis, staphylococcal scalded skin syndrome, BCGosis, and the recently described multisystemic inflammatory syndrome in children (MIS-C) associated with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) virus. Results Rash, fever, and laboratory markers of inflammation can be present in several childhood diseases that may mimic KD. Conclusion The term 'Kawasaki syndrome' instead of 'Kawasaki disease' may be more appropriate. Physicians should consider an alternative diagnosis that may mimic KD, particularly considering MIS-C during the present pandemic, as an aggressive diagnostic and therapeutic approach is needed.

Background Oral ivermectin is a safe broad spectrum anthelminthic used for treating several neglected tropical diseases (NTDs). Currently, ivermectin use is contraindicated in children weighing less than 15 kg, restricting access to this drug for the treatment of NTDs. Here we provide an updated systematic review of the literature and we conducted an individual-level patient data (IPD) meta-analysis describing the safety of ivermectin in children weighing less than 15 kg. Methodology/Principal findings A systematic review was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) for IPD guidelines by searching MEDLINE via PubMed, Web of Science, Ovid Embase, LILACS, Cochrane Database of Systematic Reviews, TOXLINE for all clinical trials, case series, case reports, and database entries for reports on the use of ivermectin in children weighing less than 15 kg that were published between 1 January 1980 to 25 October 2019. The protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO): CRD42017056515. A total of 3,730 publications were identified, 97 were selected for potential inclusion, but only 17 sources describing 15 studies met the minimum criteria which consisted of known weights of children less than 15 kg linked to possible adverse events, and provided comprehensive IPD. A total of 1,088 children weighing less than 15 kg were administered oral ivermectin for one of the following indications: scabies, mass drug administration for scabies control, crusted scabies, cutaneous larva migrans, myiasis, pthiriasis, strongyloidiasis, trichuriasis, and parasitic disease of unknown origin. Overall a total of 1.4% (15/1,088) of children experienced 18 adverse events all of which were mild and self-limiting. No serious adverse events were reported. Conclusions/Significance Existing limited data suggest that oral ivermectin in children weighing less than 15 kilograms is safe. Data from well-designed clinical trials are needed to provide further assurance., Author summary Oral ivermectin is a safe and efficacious drug for the treatment of neglected tropical diseases. To date, ivermectin is not indicated in children weighing less than 15 kg because there have been insufficient safety data to support a change of recommendation. A PRISMA-level systematic review was conducted, and 97 potential sources were identified. All lead investigators were contacted to share individual patient data if they could provide the minimum criteria. These were the known weights of the children less than 15 kg in whom there were possible adverse events. A total of 17 investigators replied, sharing individual-level patient data (IPD) from 15 studies, which represent a database of 1,088 children weighing less than 15 kg treated with oral ivermectin. Overall 18 adverse events were reported in 1.4% (15/1,088) of children, all of which were mild and self-limiting. No serious adverse events were recorded. These data suggest that ivermectin is safe for use in children weighing less than 15 kilograms. Further data from well-designed clinical trials are needed to assess the safety of oral ivermectin at escalating doses in children weighing less than 15 kg.

We present the case of a male infant diagnosed with IPEX (immune dysregulation, polyendocrinopathy, enteropathy, and X-linked) syndrome who presented a generalized rash with a BCG site reaction several months after vaccination. Erythema and induration at BCG site might be due to BCG which is a known complication of inborn errors of immunity with susceptibility to mycobacterial infection. However, in our patient this dermatological manifestation might be secondary to immune dysregulation, given the important role of Tregs and Th17 cells in mycobacterial immunity, similar to that observed in Kawasaki disease patients.

Introduction Hypohidrotic ectodermal dysplasia (HED) is a genetic condition typified by alterations in skin structures including sweat glands, hair, nails, and teeth. Hair findings in HED have been poorly characterized in larger series. Objective To characterize scalp and hair findings of patients with HED clinically and with trichoscopy and light microscopy. Methods A cross-sectional study in 21 pediatric HED patients was performed using available clinical and scalp dermatoscopic images, as well as pulled-hair samples for clinical evaluation, trichoscopic, and light microscopic analyses. Results Seventeen out of 21 patients (81%) were men. Twenty patients had straight hair. Sixteen patients had decreased hair density, 6 of whom had hair loss mainly in the temporal and occipital regions. Fourteen patients had hair whorls. On trichoscopy, we observed: single-hair follicular units (n = 19, 90%), scalp hyperpigmentation (n = 13, 62%), variable diameter of the hair shafts (n = 12, 57%), perifollicular scales (n = 8, 38%), scalp erythema (n = 8, 38%), and short curly pigtail hairs (n = 6, 29%). On light microscopy, findings included: hair shafts with irregular diameter (n = 7, 33%), heterogeneous hair color (n = 6, 29%), trichoptilosis (n = 2, 10%), and pili torti (n = 1, 5%). Conclusions In this series, hair findings in HED were similar to those described in previous studies. However, we describe two new clinical and two trichoscopic findings: decreased hair density mainly in the temporal and occipital regions, oblique upwards occipital hair follicles orientation, angled hairs, and short curly pigtail hairs. These heterogeneous findings may reflect the multiple factors and signaling pathways that can be affected in these syndromes.

Griscelli syndrome type 2 (GS2) features silvery-grey hair, bronzed skin and immunodeficiency.1 The only curative treatment for GS2 is haematopoietic stem cell transplantation (HSCT) which corrects the immune and haematologic defects with persistence of oculocutaneous abnormalities.

Rationale: Kawasaki disease (KD) is an acute vasculitis of small and medium vessels; whereas systemic lupus erythematosus (SLE) is a chronic systemic autoimmune disease. Their presentation is varied and not always straightforward, leading to misdiagnosis. There have been case reports of lupus onset mimicking KD and KD presenting as lupus-like. Coexistence of both diseases is also possible. Patient concerns: We present three adolescents, one with fever, rash, arthritis, nephritis, lymphopenia, and coronary aneurysms, a second patient with rash, fever, aseptic meningitis, and seizures, and a third patient with fever, rash, and pleural effusion. Diagnoses: The first patient was finally diagnosed with SLE and KD, the second patient initially diagnosed as KD but eventually SLE and the third patient was diagnosed at onset as lupus but finally diagnosed as KD. Interventions: The first patient was treated with IVIG, corticosteroids, aspirin, coumadin and mycophenolate mofetil. The second patient was treated with IVIG, corticosteroids and methotrexate and the third patient with IVIG, aspirin and corticosteroids. Lessons: Both diseases may mimic each other's clinical presentation. KD in adolescence presents with atypical signs, incomplete presentation, and develop coronary complications more commonly. An adolescent with fever and rash should include KD and SLE in the differential diagnosis.

There are no pathognomonic histopathological features to distinguish acute graft-vs-host disease (aGVHD) from skin drug reactions (SDRs) in pediatric patients with multiple drug regimens that have received blood transfusions and/or transplants. We aimed to determine if the addition of apoptosis markers is helpful to distinguish aGVHD from SDRs in these patients.Skin biopsy specimens from patients with a clinical diagnosis of aGVHD or SDRs were evaluated for the presence of apoptotic bodies, satellitosis, interface damage, vasculitis, and inflammatory infiltrate on HE stain. Information was completed with apoptotic markers (transferase-mediated dUTP nick end-labeling [TUNEL], bcl-2, and caspase-3).The skin biopsy specimens of 32 patients with aGVHD and 11 with SDRs were included for study. Only the number of apoptotic keratinocytes per 10 high-power fields (hpf) showed a significant difference between both groups (P = 0.02); the presence of ≥4 apoptotic keratinocytes per 10 hpf was identified as the optimal cut-off point to discriminate aGVHD from SDRs. No SDRs cases had follicular apoptotic cells. TUNEL, bcl-2, and caspase-3 determination showed no difference between both groups.The presence of ≥4 apoptotic keratinocytes per 10 hpf (in aGVHD) and the absence of follicular apoptotic cells (in SDRs) might be a useful marker to distinguish between them.

Infantile hemagiomas (IH) are the most common soft tissue tumors in infancy. They are characterized by significant growth during the first months of life, followed by slow spontaneous involution over the ensuring years. The process of involution takes several years, but usually the regression of most of the tumors ends at 4 years of age. Unfortunately, some of the IH develop complications, resulting in functional impairment, pain and disfigurement. The decision to start treatment and the choice of the best therapeutic option (topic or systemic) should be individualized depending on several factors: the size of the lesion, the location, the presence of complications such as ulceration, the risk of scarring or disfigurement, the age of the patient, the rate of growth or regression at the time of diagnosis, the risks and benefits of the treatment, the availability of the medication, the costs, and the experience of the attending physician.Los hemagiomas infantiles (HI) son los tumores de tejidos blandos más frecuentes de la infancia. Se caracterizan por un crecimiento significativo durante los primeros meses de vida, seguido de una involución lenta y espontánea a lo largo de un periodo que puede durar algunos años. Usualmente, la regresión de la mayor parte del tumor termina a los 4 años de edad. Sin embargo, algunos de los HI desarrollan complicaciones, lo que resulta en alteraciones funcionales, dolor y desfiguramiento. La decisión de administrar tratamiento a un paciente con HI y elegir la mejor opción terapéutica para ese paciente (tratamiento tópico o sistémico) debe ser individualizada, dependiendo de varios factores: el tamaño de la lesión, la localización, la presencia de complicaciones como ulceración, el riesgo de cicatrización o desfiguramiento, la edad del paciente, la tasa de crecimiento o de involución al momento del diagnóstico, los riesgos y beneficios de administrar el tratamiento, la disponibilidad del medicamento, los costos y la experiencia del médico tratante.

Infantile hemagiomas (IH) are the most common soft tissue tumors in infancy. They are characterized by significant growth during the first months of life, followed by slow spontaneous involution over the ensuring years. The process of involution takes several years, but usually the regression of most of the tumors ends at 4 years of age. Unfortunately, some of the IH develop complications, resulting in functional impairment, pain and disfigurement. The decision to start treatment and the choice of the best therapeutic option (topic or systemic) should be individualized depending on several factors: the size of the lesion, the location, the presence of complications such as ulceration, the risk of scarring or disfigurement, the age of the patient, the rate of growth or regression at the time of diagnosis, the risks and benefits of the treatment, the availability of the medication, the costs, and the experience of the attending physician.

I Generalidades La piel funciona como barrera entre el cuerpo y el medio ambiente al prevenir la pérdida de líquidos y electrolitos, regular la temperatura corporal y proteger contra infecciones y diversos estímulos mecánicos, térmicos, y ambientales. Además, es esencial para el sentido del tacto y la síntesis de vitamina D.1-4En el niño la piel es frágil, delgada y más propensa a dermatitis e infecciones.2,5,6 Mientras que en el adolescente, la piel experimenta cambios secundarios al alza en los andrógenos circulantes, que se traducen en mayor producción de sebo y predisposición al acné.7

Morphoea, also known as localized scleroderma, is a disorder characterized by excessive collagen deposition leading to thickening of the dermis and/or subcutaneous tissues. Intravenous IgG therapy has induced improvement in some fibrotic conditions. The primary indication for subcutaneous IgG (SCIG) is in primary immunodeficiency disorders as replacement therapy; however, recently there has been considerable interest in SCIG as an immunomodulatory agent. We report an 11-year-old girl with deep morphoea who was successfully treated with SCIG.

La dermatitis atópica es la enfermedad cutánea inflamatoria más común, afecta principalmente a los niños (prevalencia de 20%) y suele iniciarse antes de los 5 años (90%).1 El curso clínico es crónico y genera recidiva; dos tercios de los pacientes se controlan en la etapa adulta.2 La fisiopatología resulta de la interacción de factores genéticos, inmunológicos y ambientales, con disfunción de la barrera cutánea y desequilibrio inmunitario, además de elevada pérdida transepidérmica de agua, inflamación y mayor permeabilidad a los alergenos, irritantes y microorganismos.3

Superficial granulomatous pyoderma gangrenosum, a rare variant of pyoderma gangrenosum, has been considered to be the most benign form of the disease. We present the case of a 15-year-old boy with pulmonary involvement and nodular scleritis associated with this unusual type of pyoderma gangrenosum and discuss its differential diagnosis.

Trisomy 13, or Patau syndrome, is a chromosomal disorder that can occur in complete, partial, or mosaic forms. Mosaicism is observed in 6% of individuals with trisomy 13 and, in contrast to the complete form, has wide phenotypic variability, longer survival, and in some patients an unusual skin pigmentary pattern similar to phylloid hypomelanosis. We describe here a 12-year-old girl with trisomy 13 mosaicism (mos 47,XX,+13[9]/46,XX[16]) who had three major malformations, an unusual skin pigmentary pattern, and prolonged survival.

BACKGROUND: Morphea is an inflammatory disease with diffuse thickening and hardening of the skin. It is common in children and it has been reported that as many as 40% have extracutaneous articular and neurological manifestations, vascular and ocular disorders, and gastrointestinal or respiratory symptoms.RATIONALE: There are no studies of associated extracutaneous manifestations in Mexican children with morphea.OBJECTIVE: Describe clinical characteristics, frequency of extracutaneous manifestations, and treatment of pediatric patients with morphea who received care at the Instituto Nacional de Pediatría.MATERIAL AND METHODS: A retrospective study of patients with morphea, 1 to 18 years of age, who received care between January 1, 2000, and December 31, 2015.RESULTS: Thirty-two patients with morphea were included, half (n = 16) with the linear subtype, followed by plaque-type morphea in 7 (22%). Extracutaneous manifestations were reported in 23 (72%) patients; the most common were: musculoskeletal in 23 (72%), neurological in 9 (28%), and ophthalmological in 3 (9%). Twenty-three patients (72%) required systemic treatment. Nineteen patients (60%) required orthopedic and surgical treatment for complications. The clinical evolution was toward remission in 72% of the patients (n = 23).CONCLUSIONS: In this series of 32 cases of children with morphea, 72% had extracutaneous manifestations, principally musculoskeletal and neurological. It is important to conduct targeted questioning, and if necessary perform paraclinical studies, to identify extracutaneous manifestations which may be associated with morphea, especially when it is linear or extensive.

Dermoid cysts (DCs) are benign cutaneous tumors that tend to persist and grow. The aim of this study was to examine the clinicopathologic features of congenital DCs. We present a case series of 75 children with a clinicopathologic diagnosis of DC. Seventy-two cysts were located on the head, one on the neck, and two on the trunk. Six cysts were located along the midline. Eight patients had symptoms other than changes in cyst size. Imaging studies were performed on 15 patients. Surgical excision was the primary treatment in all 75 cases. Neurosurgery and ophthalmology services were involved in the care of some patients. Histopathologic studies reported a foreign body giant cell reaction in 17 of the cysts. No recurrence was documented. DCs can remain stable for years, but they can become symptomatic as a result of enlargement and rupture or, more rarely, as a result of extension into surrounding tissues. Physicians should be aware that certain locations have a higher risk of DC extension, and adequate diagnostic investigations should be performed before their complete resection.

The common manifestations of atopic dermatitis (AD) appear sequentially with involvement of the cheeks in infancy, flexural extremities in childhood, and hands in adulthood. Although less common clinical manifestations are well described, they have not been the subject of epidemiologic studies to describe their prevalence in specific age groups. This observational, cross-sectional, comparative study included 131 children younger than 18 of both sexes with AD who attended the clinics of the Dermatology Department of the National Institute of Pediatrics in Mexico City. Patients were examined to determine the presence of infrequent clinical manifestations of AD during infancy, preschool and school age, and adolescence and stratified according to sex, age, and number of clinical signs. A chi-square test was used to detect differences according to age and sex. Logistic regression analysis was also performed. The main findings according to age were genital dermatitis and papular-lichenoid dermatitis variant in infants; atopic feet, prurigo-like, nummular pattern, and erythroderma in preschool and school-aged children; and eyelid eczema and nipple dermatitis in adolescents. The risk of development of nipple dermatitis and eyelid eczema increased with age, and the development of genital dermatitis decreased with age. The knowledge of the prevalence of less common clinical manifestations of AD according to age in different populations might be helpful in diagnosing incipient cases of AD.

El acné juvenil o acné vulgar es una enfermedad inflamatoria crónica que afecta a la unidad pilosebácea. La producción de sebo por las glándulas sebáceas, secundaria al estímulo hormonal, condiciona un proceso obstructivo del conducto pilosebáceo por retención de sebo y células anormales seguido de un proceso inflamatorio. Generalmente es de inicio lento, de evolución prolongada, con remisiones parciales y brotes agudos.

El uso prolongado de esteroides tópicos en niños se puede asociar con efectos adversos locales y sistémicos. Se presenta el caso de una paciente de seis meses de edad con síndrome de Cushing iatrogénico y sarna costrosa tras el uso de betametasona al 0.05% en el área del pañal. La sarna costrosa es una variedad de escabiosis que tiene la particularidad de ser más extensa y más contagiosa; generalmente se observa en pacientes inmunodeprimidos. En este caso fue favorecida por la aplicación crónica de esteroides tópicos. Los médicos de primer contacto y los padres deben conocer los efectos secundarios potenciales de los esteroides tópicos, especialmente en áreas de piel delgada o cubierta (como el área del pañal) en donde la absorción de los esteroides tópicos se incrementa.

Keratosis lichenoides chronica (KLC) is a rare acquired disease of adulthood, of unknown etiology, characterized by keratotic parallel linear lesions, retiform plaques, and keratotic, often follicular papules, chronicity and lichenoid histopathologic features. KLC of pediatric onset is considered extremely rare. Its features and relationship to adult onset KLC are unknown. We studied 8 cases of pediatric-onset KLC in the literature and 6 personal cases and compared them with 40 reported adult-onset KLC patients. The following features characterize pediatric-onset KLC: familial occurrence; probable autosomal recessive inheritance; early or congenital onset with facial erythemato-purpuric macules; forehead, eyebrow, and eyelash alopecia; pruritus; and a low frequency of other cutaneous and systemic abnormalities. Pediatric-onset KLC may represent a different disease or a subset of adult-onset KLC, with special genetic and clinical characteristics. Determining its precise nosology will have prognostic and therapeutic implications.

Background. Subungual osteochondromas are relatively rare. Objective. The objective was to evaluate the clinical, histologic, radiologic, and therapeutic features of subungual osteochondroma. Methods. We retrospectively analyzed 27 cases of subungual osteochondroma evaluating the clinical manifestations, the radiologic and histologic features, and the treatment. Results. There were 20 females and 7 males. The first toe was the most commonly involved. Previous trauma was recalled in 40.7% of the cases. Subungual osteochondromas appeared as firm, exophytic tumors beneath the ungual plate. Twenty-five patients had pain. The radiologic films demonstrated the presence of a juxtaephiphyseal radiodense cap surrounded in some cases by cortical bone. A Dubois-like excision was performed to expose the tumor and cut it through the base, followed by curettage of the bony bed. Radiologic controls were taken 30 and 60 days after surgery and in cases of symptomatology. There were three cases of recurrence and two cases of incomplete excision. Conclusions. Subungual osteochondroma should be distinguished from other subungual masses. The diagnosis of subungual osteochondroma is clinicoradiologic.

Acquired diffuse hyperpigmentation in children secondary to metabolic disorders can be divided into nutritional diseases, endocrinological disorders, and metabolic causes. Although pigmentation is categorized as diffuse, it is often accentuated in some areas. Adequate approach of diffuse hyperpigmentation may lead to the early diagnosis of a specific disease. The initial and most prominent sign can be in the skin and thus the dermatologist is the first physician consulted.

Hydroa vacciniforme-like lymphoma (HVLL) is an Epstein-Barr virus (EBV)-positive T-cell lymphoproliferative disorder of childhood that occurs mainly in Central and South America and Asia. We present the clinicopathological features of 20 Mexican children with HVLL with a median age of 8 years at diagnosis (range, 1-15). All patients presented with skin lesions involving sun-exposed areas, but not exclusively. Fever, lymphadenopathy, and hepatosplenomegaly were often observed. Most patients were treated with immunomodulators and/or immunosuppressive agents, resulting in temporary remission. For 13 patients follow-up was available for a median of 3 years (range, 1 month-13 years). Three patients with long follow-up (9-13 years) are alive with disease. Four patients died, 2 after developing systemic lymphoma. Histologically, the skin showed a predominantly angiocentric and periadnexal Epstein-Barr early RNA+ lymphoid infiltrate with variable atypia and subcutaneous involvement. Fifteen patients showed a T-cell phenotype (12, αβ; 2, γδ; 1, silent phenotype) and monoclonal T-cell receptor-γ rearrangements, whereas 6 exhibited a natural killer (NK)-cell phenotype. Four patients had hypersensitivity to mosquito bites. One patient showed both phenotypes. HVLL is an EBV-associated lymphoproliferative disorder of αβ-, γδ-, or NK-cell phenotype with a broad clinical spectrum, usually prolonged clinical course, and risk for progression to systemic disease.

A 33 year-old woman presented with numerous 3- to 5-mm red-brown and yellow-brown dome-shaped nodules, primarily located on the scalp, dorsal aspects of the forearms, and lower extremities (Figure 1 and Figure 2). Her lesions started to appear 5 years prior to her consultation with increasing number and without spontaneous regression. Findings from a previous biopsy revealed epithelioid dermatofibroma. The remainder of the physical examination was unremarkable. There were no familial cases of this condition (both the mother and two older sisters were examined).

The common manifestations of atopic dermatitis (AD) appear sequentially with involvement of the cheeks in infancy, flexural extremities in childhood, and hands in adulthood. Although less common clinical manifestations are well described, they have not been the subject of epidemiologic studies to describe their prevalence in specific age groups. This observational, cross-sectional, comparative study included 131 children younger than 18 of both sexes with AD who attended the clinics of the Dermatology Department of the National Institute of Pediatrics in Mexico City. Patients were examined to determine the presence of infrequent clinical manifestations of AD during infancy, preschool and school age, and adolescence and stratified according to sex, age, and number of clinical signs. A chi-square test was used to detect differences according to age and sex. Logistic regression analysis was also performed. The main findings according to age were genital dermatitis and papular-lichenoid dermatitis variant in infants; atopic feet, prurigo-like, nummular pattern, and erythroderma in preschool and school-aged children; and eyelid eczema and nipple dermatitis in adolescents. The risk of development of nipple dermatitis and eyelid eczema increased with age, and the development of genital dermatitis decreased with age. The knowledge of the prevalence of less common clinical manifestations of AD according to age in different populations might be helpful in diagnosing incipient cases of AD.

Rarely, systemic lupus erythematosus (SLE) presents with bullous lesions due to severe edema and hydropic degeneration of the basal layer, or as a subepidermal blistering disease. Here, we describe two Mexican teenagers, one with SLE with blisters and another with bullous SLE. We also discuss the mechanisms and clinical implications of lesion formation in patients with SLE and bullae.

Lipofibromatous hamartoma of nerve (LFHN) is a very uncommon benign lipomatous tumor with specific clinicopathological characteristics which may present with or without macrodactyly. This tumor-like lesion is composed of fibrous and fatty tissues arising from the epi- and perineurium that surrounds and infiltrates the major nerves and their branches in the body (Enzinger and Weiss 1994). It is believed to be congenital and mainly affects the median nerve in the hand or more rarely the digital nerves at the peripheral level usually well before the third decade (Razzaghi and Anastakis 2005, Jung et al. 2005). An association between this condition and overgrowth of bone and macrodactyly is present in about one-third of cases (Barsky 1967).

Darter’s disease is an autosomal dominant acantholytic disorder (OMIM # 124200) characterized by a peculiar keratinization of the epidermis, nails, and mucous membranes, resulting in a persistent eruption of keratotic papules predominantly in seborrheic areas (upper and central trunk, flexures, scalp and forehead), palmar pits and nail dystrophy. Involvement may be severe, with widespread itchy malodorous crusted plaques, painful erosions, blistering, and mucosal lesions. Secondary infection is common. Sun, heat, and sweating exacerbate the disease, which never remits (even though oral retinoids may reduce hyperkeratosis). Neuropsychiatric abnormalities including mild mental retardation, epilepsy, and schizophrenia have been reported in some families (Burge and Wilkinson 1992, Jacobsen et al. 1999): whether this association is due to pleiotropism of the mutated gene or reflects coincidence is not clear (OMIM 2006). Several variants have been described (see below).

There are two types of tyrosinemia: tyrosinemia type 1 due to fumarylacetoacetase deficiency which is a hepatorenal form without skin abnormalities, and tyrosinemia type II or Richner—Hanhart Syndrome due to hepatic cytosolic aminotransferase deficiency, which is the oculocutaneous form of the disease we will discuss in this chapter.

Keratitis-ichthyosis-deafness (KID) syndrome is a genetically determined disorder of keratinization, a congenital ichthyosiform dermatosis with additional extracutaneous features (keratitis and deafness). Because of the association of ichthyosis or ichthyosiform dermatosis with central and/or peripheral nervous system involvement, KID syndrome has been (and is) traditionally defined as a neuroichthyosis or neurocutaneous disorder.