Authors:
Wynnis Tom, M.D., Fellow, Pediatric and Adolescent Dermatology, University of California, San Diego, and Rady Children's Hospital, San Diego
Lawrence F. Eichenfield, M.D., Chief, Pediatric and Adolescent Dermatology, Pediatric and Adolescent Dermatology, University of California, San Diego, and Rady Children's Hospital, San Diego.

Introduction

The Society for Pediatric Dermatology held its 20^th Annual Pre-American Academy of Dermatology Meeting in San Antonio, Texas, on Thursday, January 31, 2008. The meeting featured expert speakers providing updates on diseases, therapies, and the practice of medicine. Cases requiring diagnosis and those demonstrating important principles were also presented. Highlights from the meeting are presented here.

Autoimmune Bullous Diseases in Children

The target antigens in many immunobullous diseases have now been defined, aiding in their diagnosis. Kim Yancey, M.D., Professor and Chairman, Department of Dermatology, University of Texas Southwestern Medical Center, discussed using enzyme-linked immunosorbent assays (ELISA) to quantify IgG antibodies against desmogleins involved in the pathogenesis of pemphigus vulgaris and foliaceus.¹ These new assays give a unit value and have increased sensitivity and specificity compared to traditional immunofluorescence techniques.²

Dr. Yancey also highlighted features of each acquired immunobullous disease. Chronic bullous dermatosis of childhood is most common and can present in a dramatic, eruptive manner, but most cases remit within two years. Childhood pemphigus vulgaris features more relapsing bouts of disease. Rituximab, a monoclonal antibody to CD20 used for refractory cases in adults, has now been reported to have efficacy in children.³ Blistering does not tend to occur in neonates born to mothers with pemphigus foliaceous. Neonatal expression of desmoglein 3 at all levels of the epidermis maintains cell-cell adhesion and compensates for maternal antibody-induced loss of desmoglein 1.⁴ Paraneoplastic pemphigus can be associated with pulmonary injury. The need to monitor pulmonary function tests and prevent bronchiolitis obliterans was emphasized. Pemphigoid in children may present as localized vulvar blisters and erosions and needs to be differentiated from lichen sclerosus. Dr. Yancey recommended skin biopsy to differentiate the two conditions, but serologic testing for antibodies to bullous pemphigoid-antigen 2 can be performed if biopsy is not possible. ,

Epidermolysis Bullosa Update

Anna Bruckner, M.D., Director of Pediatric Dermatology, Packard Children's Hospital and Assistant Clinical Professor of Dermatology and Pediatrics, Stanford Medical School, discussed proposed revisions to the classification system for epidermolysis bullosa.⁵ The new system is based on clinical findings rather than gene mutations alone.⁶ Epidermolysis bullosa (EB) simplex is divided into basal and suprabasal groups, with two new forms added— lethal acantholytic EB (due to desmoplakin defect) and ectodermal dysplasia with skin fragility (plakophilin 1 defect). Diagnosis and classification of appropriate subtype is important in determining prognosis and recurrence risk in families. Immunofluorescence antigenic mapping is now considered the best method for diagnosing EB, with 97% sensitivity and 100% specificity.⁷

Dr. Bruckner also addressed several important components of care for patients with EB. Nutritional support is a key part of management and guidelines are available.⁸ The need to routinely screen for decreased bone mineralization was emphasized for junctional and recessive dystrophic EB (RDEB). Renal failure is the second leading cause of death after 15 years of age in individuals with RDEB and screening should begin in the teenage years.⁹