Localized eruptive porokeratosis in pediatric patients following treatment of acute leukemia.

Porokeratosis is a rare diagnosis in the pediatric population, and eruptive disease has been documented prior in patients with history of stem cell transplantation. Comparing various porokeratosis eruptions between patients can be difficult due to limitations in current classification and nomenclature. Here, we discuss a single-institution case series of three children who developed porokeratosis following hematopoietic stem cell transplantation for acute leukemia, and we propose that this presentation be termed localized eruptive porokeratosis (LEP). We present the distinguishing features of this variant by discussing the shortcomings in current nomenclature and also examine the association between porokeratosis and hematopoietic stem cell transplantation in the pediatric population.

Poroqueratosis. Revisión de su etiopatogenia, manifestaciones clínicas, diagnóstico y tratamiento / Porokeratosis: A Review of Its Pathophysiology, Clinical Manifestations, Diagnosis, and Treatment

Las poroqueratosis son un grupo heterogéneo e infrecuente de dermatosis adquiridas o heredadas de etiología desconocida, caracterizadas por un trastorno de la queratinización secundario a una expansión clonal anormal de los queratinocitos. Se han descrito múltiples mutaciones genéticas potencialmente implicadas. Histológicamente, se caracterizan por la presencia de la lamela cornoide. Su presentación clínica es variable con formas localizadas, diseminadas e incluso eruptivas. Las poroqueratosis se han asociado con inmunosupresión, radiación ultravioleta, enfermedades sistémicas, infecciosas y neoplásicas. Muchos autores las consideran como entidades premalignas dada su potencial degeneración neoplásica a carcinoma escamoso o basocelular. Por ello, el seguimiento a largo plazo es uno de los pilares de su tratamiento, el que suele ser complejo y a menudo insatisfactorio. En la presente revisión se discuten los últimos avances en su etiopatogenia, diagnóstico y terapéutica, y se propone un algoritmo de tratamiento

Porokeratosis comprises a group of heterogeneous and uncommon acquired or congenital skin diseases of unknown origin characterized by a keratinization disorder resulting from abnormal clonal expansion of keratinocytes. Numerous genetic mutations are thought to be involved. These conditions are characterized histologically by the presence of a cornoid lamella. Clinical manifestations are variable, with localized, disseminated, and even eruptive forms. Porokeratosis has been associated with immunosuppression, ultraviolet radiation, and systemic, infectious, and neoplastic diseases. Many authors consider it to be a premalignant condition because of the potential for malignant transformation to squamous cell or basal cell carcinoma. Therefore, long-term follow-up is a key component of treatment, which is usually complex and often unsatisfactory. We review the latest advances in our understanding of the pathogenesis, diagnosis, and treatment and propose a treatment algorithm

Clinical course of porokeratosis ptychotropica over 7 years in an otherwise healthy child.

Porokeratosis ptychotropica is an unusual variant of porokeratosis characterized by papules and plaques located on the buttocks and gluteal cleft and showing multiple coronoid lamellae on histology. In this case report, we present the longitudinal clinical course of porokeratosis ptychotropica in a pediatric patient with individual red-brown hyperkeratotic lesions that enlarged and became confluent prior to surgical intervention. We also discuss the etiology of porokeratosis ptychotropica and review current as well as future treatment options for the disease.

Pink verrucous plaque in a man with systemic mastocytosis.

Porokeratosis ptychotropica is a rare and commonly misdiagnosed subtype of porokeratosis involving the body folds. We present a 53-year-old man with systemic mastocytosis who presented with a pruritic, verrucous plaque in the gluteal fold that showed multiple cornoid lamellae on histopathologic evaluation, diagnostic of porokeratosis ptychotropica. Various treatments have been reported, including topical corticosteroids, retinoids, vitamin D analogs, calcineurin inhibitors, imiquimod, phototherapy, cryotherapy, or ablative laser therapy, but recurrences are common.

Eruptive Disseminated Porokeratosis in a Patient With Type 2 Diabetes Mellitus.

Porokeratosis includes a group of heterogenous disorders that represents distinct clinical subtypes of the same genetic pattern. Although entire pathogenesis of porokeratosis still remains unknown, certain factors including ultraviolet radiation and immunosuppression are suggested to be some of the factors inducing this disorder. Eruptive disseminated porokeratosis is a recently described form of porokeratosis, which frequently occurs in the presence of immunosuppresion or malignancy. The authors report here a unique case with sudden onset eruptive disseminated porokeratosis associated with diabetes mellitus.

Imiquimod and Photodynamic Therapy Are Useful in the Treatment of Porokeratosis in Children with Bone Marrow Transplantation.

Porokeratosis is an uncommon disorder that affects keratinization. Immunosuppression may favor the development of porokeratotic lesions. Patients who receive allogenic transplants represent a therapeutic challenge to dermatologists. We report two cases of porokeratosis in children with bone marrow transplant and their excellent response to imiquimod and photodynamic therapy.

Porokeratoses: an update of clinical, aetiopathogenic and therapeutic features.

Porokeratoses represent a group of uncommon, acquired or hereditary dermatoses, due to a keratinization disorder whose origin is still unclear; they could be due to the expansion of a clone of abnormal epidermal keratinocytes. Several clinical forms exist, of which the most common is disseminated superficial actinic porokeratosis; other forms include Mibelli, disseminated superficial, linear, palmoplantaris punctata and palmaris, plantaris et disseminata. These may coexist in the same patient or in different members of the same family. Porokeratoses manifest clinically with annular or linear, well-circumscribed keratotic plaques and share a common histological hallmark, the cornoid lamella, a vertical stack of parakeratotic corneocytes within the horny layer resting on a shallow depression of the underlying epidermis. Porokeratoses may be seen in the setting of various immunodeficiencies, namely in organ-transplant recipients, in whom the course of the disease may parallel the degree of immunosuppression. The overall prognosis of porokeratoses is favourable but is shadowed by the possibility of malignant transformation of the lesions (usually into squamous cell carcinoma); this happens in less than 10% of cases but may prove fatal. Although several surgical or medical (local or systemic) treatments have been tried, none of them has shown consistent and long-term efficacy.

Efficacy of acitretin for porokeratosis in a child with chronic cutaneous graft versus host disease.

Porokeratosis is a rare disorder of epidermal keratinization that is regarded as a precancerous. Recipients of hematopoietic stem cell transplantation (HSCT) have a greater risk of skin cancer; chronic graft versus host disease (GVHD) is an additional risk factor. A 16-year-old boy who had received HSCT for acute myelogenous leukemia was referred to us for sclerodermoid chronic cutaneous GVHD. Two years later, he developed disseminated porokeratosis with a few atypical lesions. Despite cryotherapy, numerous lesions of porokeratosis recurred rapidly. Acitretin resulted in good clinical response and reduced the rate of onset of new lesions.

Porokeratosis in Singapore: an Asian perspective.

Porokeratosis is a rare disorder of skin keratinisation characterised by a cornoid lamella. We reviewed its associations with immunosuppression and phototherapy, as well as the risks of malignant progression. This is a retrospective review on all cases of porokeratosis seen at the National Skin Centre, Singapore, between 2000 and 2010. A total of 94 patients were reviewed. Clinical and histological diagnoses were confirmed in 63% patients. Most patients were Chinese (89%) with a mean age of 51.6 years. The male to female ratio was 1.4:1. The four main clinical variants were classical porokeratosis of Mibelli (56%), disseminated superficial actinic porokeratosis (DSAP) (18%), disseminated superficial porokeratosis (DSP) (11%), and linear porokeratosis (13%). Phototherapy-induced porokeratosis, seen in three patients, is rare. Seven cases of porokeratosis occurred in patients who were immunosuppressed. Progression of porokeratosis to malignancy is uncommon and was observed in three patients. The most common treatments included cryotherapy (26.5%) as well as topical steroids or retinoids (38.1%). A good response, defined as clear or almost clear lesions, occurred in 16% patients. The most common presentation of porokeratosis in our review was a middle-aged male patient with an asymptomatic lesion of porokeratosis of Mibelli over the extremities. No particular immunosuppressive drug was implicated. Porokeratosis associated with ultraviolet phototherapy or malignancy is rare. Progression of porokeratosis to malignancy arose in the disseminated variants, with a possible correlation with age. This is the largest institutional retrospective review of porokeratosis to date and highlights the major epidemiological characteristics of this condition.

Porokeratosis: present concepts.

Porokeratosis represents a group of disorders of epidermal keratinization which are characterized by the histopathological feature of the cornoid lamella, a column of tightly fitted parakeratotic cells. The aetiology of porokeratosis is still unclear. This review summarizes the currently available data on the pathophysiology of this condition and discusses the clinical variants and the currently available therapies.

Disseminated superficial actinic porokeratosis in a patient undergoing treatment with long-term narrowband ultraviolet B for psoriasis.

Disseminated superficial actinic porokeratosis (DSAP) is a subtype of porokeratosis, thought to be clonal disorder of keratinization. Chronic exposure to ultraviolet (UV) light might be an etiological cause of DSAP, of which frequent sites are sun-exposed areas. We report a case of DSAP that occurred on the trunk of a 79-year-old man with psoriasis treated with narrowband ultraviolet B (NB-UVB) for clearing and maintenance therapies. DSAP has been reported to associate with psoralen and ultraviolet A therapy and broadband UVB, but not NB-UVB. This may be the first case of DSAP after repeated exposure to NB-UVB.

Development of disseminated superficial porokeratosis in a patient with complicated acute pancreatitis.

Porokeratosis is a group of hereditary or acquired diseases with abnormal epidermal keratinization. A 71-year-old man was admitted to the Surgery Department after an attack of acute pancreatitis complicated with pancreatic necrosis, which required surgical resection. Three weeks after the admission, the patient was observed by our Dermatology department with sudden onset of a generalized eruption of asymptomatic flat papules with a hyperkeratotic rim, sparing the face, palms, soles, and mucous membranes. A skin biopsy was performed at the border of a leg lesion, which disclosed the presence of cornoid lamella, confirming the clinical diagnosis of disseminated superficial porokeratosis (DSP). The skin eruption spontaneously subsided about one month after pancreatic resection. The late onset of DSP in our patient may represent a type of immunosuppression-induced porokeratosis. Possibly, the pathologic clone of keratinocytes for porokeratosis was present, but remained latent until there was a decrease in the immunological status. It is possible that this relative and transient state of immunosuppression was the result of the concurrent necrotizing pancreatitis. This case represents an unusually good outcome of DSP. To the authors best knowledge, this is the first case of DSP related to severe acute pancreatitis.

Dermatopathology of skin cancer in solid organ transplant recipients.

Skin cancers occur more frequently in solid organ transplant recipients relative to the general population. Transplant recipients are at particularly high risk of squamous cell carcinoma, with up to a 100-fold increase in the relative risk when compared to the nontransplanted population. This compares with a 10- to 16-fold increase in basal cell carcinoma for renal transplant recipients. An increased incidence of melanoma in transplant patients has also been reported. Other types of skin cancer associated with immunosuppression in transplant patients include Kaposi sarcoma, Merkel cell carcinoma, and posttransplant lymphoproliferative disorder. This review discusses the epidemiology and pertinent pathologic features of each of these tumors. A brief clinical management strategy is outlined. In addition, the contribution of viral induced carcinogenesis with respect to Kaposi sarcoma, Merkel cell carcinoma, and posttransplant lymphoproliferative disorder is discussed.