Renal-skin syndromes

Kidney and Urinary Tract Involvement in Epidermolysis Bullosa: Is Routine Follow-Up Necessary?

Background

Several renal and urinary tract complications have been reported in patients with epidermolysis bullosa.

Objective

This study investigated kidney and urinary tract involvement in patients with epidermolysis bullosa.

Patients and Methods

Patients with epidermolysis bullosa in treatment at the Dermatology Unit were included in the study. Glomerular and tubular functions were investigated.

Results

The study included 16 patients (4 females, 12 males) of mean 11.1 years (SD = 8.1 years). Estimated GFR was normal in all patients except one with end-stage renal disease. Excluding this patient, the urinary albumin/creatinine ratio and the fractional excretion of sodium were normal. The mean beta-2 microglobulin/creatinine ratio was 278.8 μg/g, and it was abnormally high in 2 patients. The mean tubular phosphorus reabsorption was 92.6%; it was abnormally low in 1 patient. Severe kidney or urinary tract involvement was present in 2 patients with recessive dystrophic EB-generalized severe (RDEB-GS): one patient had obstructive bullous lesions in the urethra; the other had end-stage renal disease secondary to focal segmental glomerulosclerosis and was on peritoneal dialysis for 3 years.

Conclusions

Assessment for renal and urinary tract involvement should become a routine part of the evaluation of patients with any type of EB, but especially of patients with RDEB-GS. Patients with mild tubular dysfunction need long-term follow-up to detect early deterioration of renal function.

From Skin to Kidneys: Cutaneous Clues of Renal Disease in Children

Background

The skin is often seen as a world apart, but not rarely do cutaneous manifestations reveal signs of systemic disease.

Objectives

The aim of this review is to include in one paper all the possible correlations between nephrological and dermatological manifestations of the same disease in pediatric patients while also keeping in mind that in apparent exclusively dermatological diseases there can be nephrological manifestations as part of the same disorder and vice versa.

Methods

We searched on PubMed for a possible link between skin and kidney matching the following terms and correlated MeSH terms: dermatology, skin, kidney, renal disease, nephrology, pediatrics, child, childhood, vasculitis, and cancer. We selected only articles reporting a link between nephrology and dermatology in pediatrics, and they are all included in this comprehensive review.

Results

Kawasaki disease, Henoch-Schönlein purpura, systemic lupus erythematosus, Dent disease, subcutaneous fat necrosis, Langerhans cell histiocytosis, renal cell carcinoma, non-Hodgkin lymphoma, tuberous sclerosis complex and syndromes with increased risk for Wilms tumor, Fabry disease, nail-patella syndrome, neurofibromatosis type 1, Beckwith-Wiedemann syndrome, Adams-Oliver syndrome 1, Apert syndrome, Fanconi pancytopenia syndrome, Pallister-Hall syndrome, and Fanconi pancytopenia syndrome are all conditions in which there can be both nephrological and dermatological manifestations in children.

Conclusions

We could not find any reports that focused attention on the link between nephrological and dermatological manifestations of the same disease in children. It is also important for clinicians to keep in mind that in what may appear to be an exclusively dermatological disease, there can be nephrological manifestations as part of the same disorder and vice versa.

Epidermolysis bullosa

Epidermolysis bullosa (EB) is an inherited, heterogeneous group of rare genetic dermatoses characterized by mucocutaneous fragility and blister formation, inducible by often minimal trauma. A broad phenotypic spectrum has been described, with potentially severe extracutaneous manifestations, morbidity and mortality. Over 30 subtypes are recognized, grouped into four major categories, based predominantly on the plane of cleavage within the skin and reflecting the underlying molecular abnormality: EB simplex, junctional EB, dystrophic EB and Kindler EB. The study of EB has led to seminal advances in our understanding of cutaneous biology. To date, pathogenetic mutations in 16 distinct genes have been implicated in EB, encoding proteins influencing cellular integrity and adhesion. Precise diagnosis is reliant on correlating clinical, electron microscopic and immunohistological features with mutational analyses. In the absence of curative treatment, multidisciplinary care is targeted towards minimizing the risk of blister formation, wound care, symptom relief and specific complications, the most feared of which - and also the leading cause of mortality - is squamous cell carcinoma. Preclinical advances in cell-based, protein replacement and gene therapies are paving the way for clinical successes with gene correction, raising hopes amongst patients and clinicians worldwide.

Inherited epidermolysis bullosa: New diagnostics and new clinical phenotypes

Inherited epidermolysis bullosa (EB) is a group of heterogeneous genetic disorders characterized by skin fragility. EB comprises a large spectrum of phenotypes, ranging from severe cutaneous and extracutaneous involvement caused by lack of key adhesion proteins, to mild cutaneous fragility caused by subtle molecular defects. Disease-causing variants in 20 different genes account for the genetic and allelic heterogeneity of EB. Here, we discuss the development of laboratory methods that enabled these discoveries and the clinical and molecular features of some new EB entities elucidated during the past 5-6 years.

Update on Genetic Conditions Affecting the Skin and the Kidneys

Genetic conditions affecting the skin and kidney are clinically and genetically heterogeneous, and target molecular components present in both organs. The molecular pathology involves defects of cell-matrix adhesion, metabolic or signaling pathways, as well as tumor suppressor genes. This article gives a clinically oriented overview of this group of disorders, highlighting entities which have been recently described, as well as the progress made in understanding well-known entities. The genetic bases as well as molecular cell biological mechanisms are described, with therapeutic applications.