Staphylococcal Scalded Skin Syndrome and Bullous Impetigo

Staphylococcal scalded skin syndrome (SSSS) and bullous impetigo are infections caused by Staphylococcus aureus. The pathogenesis of both conditions centers around exotoxin mediated cleavage of desmoglein-1, which results in intraepidermal desquamation. Bullous impetigo is due to the local release of these toxins and thus, often presents with localized skin findings, whereas SSSS is from the systemic spread of these toxins, resulting in a more generalized rash and severe presentation. Both conditions are treated with antibiotics that target S. aureus. These conditions can sometimes be confused with other conditions that result in superficial blistering; the distinguishing features are outlined below.

An Updated Review of Pemphigus Diseases

Clinicians may encounter a variety of skin conditions that present with vesiculobullous lesions in their everyday practice. Pemphigus vulgaris, pemphigus foliaceus, IgA pemphigus, and paraneoplastic pemphigus represent the spectrum of autoimmune bullous dermatoses of the pemphigus family. The pemphigus family of diseases is characterized by significant morbidity and mortality. Considering the risks associated with a delayed diagnosis or misdiagnosis and the potential for overlap in clinical features and treatment, evaluation for suspected pemphigus disease often requires thorough clinical assessment and laboratory testing. Diagnosis is focused on individual biopsies for histopathology and direct immunofluorescence. Additional laboratory methods used for diagnosis include indirect immunofluorescence and enzyme-linked immunosorbent assay. Recent advancements, including anti-CD20 therapy, have improved the efficacy and reduced the morbidity of pemphigus treatment. This contribution presents updates on the pathophysiology, clinical features, diagnostic work-up, and medical management of pemphigus. Improved strategies for diagnosis and clinical assessment are reviewed, and newer treatment options are discussed.

Bullous Pemphigoid and Other Pemphigoid Dermatoses

The pemphigoid family of dermatoses is characterized by autoimmune subepidermal blistering. The classic paradigm for pemphigoid, and the most common member, is bullous pemphigoid. Its variable clinical presentation, with or without frank bullae, is linked by significant pruritus afflicting the elderly. Mucous membrane pemphigoid is an umbrella term for a group of subepidermal blistering dermatoses that favor the mucosal membranes and can scar. Epidermolysis bullosa acquisita is a chronic blistering disorder characterized by skin fragility, sensitivity to trauma, and its treatment-refractory nature. Clinicians that encounter these pemphigoid disorders may benefit from an overview of their clinical presentation, diagnostic work-up, and therapeutic management, with an emphasis on the most frequently encountered pemphigoid disease, bullous pemphigoid.

Pustular Psoriasis and Acute Generalized Exanthematous Pustulosis

The similarity between pustular psoriasis (PP) and acute generalized exanthematous pustulosis (AGEP) poses problems in the diagnosis and treatment of these two conditions. Significant clinical and histopathologic overlap exists between PP and AGEP. PP is an inflammatory disorder that has numerous clinical subtypes, but all with sterile pustules composed of neutrophils. AGEP is a severe cutaneous adverse reaction that is also characterized by non-follicular sterile pustules. Clinical features that suggest a diagnosis of PP over AGEP include a history of psoriasis and the presence of scaling plaques. Histologically, eosinophilic spongiosis, vacuolar interface dermatitis, and dermal eosinophilia favor a diagnosis of AGEP over PP. Importantly, PP and AGEP vary in clinical course and treatment. PP treatment involves topical steroids, oral retinoids, and systemic immunosuppressants. Newer therapies targeting IL-36, IL-23, IL-1, and PDE-4 have been investigated. The removal of the offending agent is a crucial part of the treatment of AGEP.

Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis: A Review of Diagnosis and Management

Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) are rare diseases that are characterized by widespread epidermal necrosis and sloughing of skin. They are associated with significant morbidity and mortality, and early diagnosis and treatment is critical in achieving favorable outcomes for patients. In this scoping review, Excerpta Medica dataBASE and PubMed were searched for publications that addressed recent advances in the diagnosis and management of the disease. Multiple proteins (galectin 7 and RIP3) were identified that are promising potential biomarkers for SJS/TEN, although both are still in early phases of research. Regarding treatment, cyclosporine is the most effective therapy for the treatment of SJS, and a combination of intravenous immunoglobulin (IVIg) and corticosteroids is most effective for SJS/TEN overlap and TEN. Due to the rare nature of the disease, there is a lack of prospective, randomized controlled trials and conducting these in the future would provide valuable insights into the management of this disease.

Large FVIII gene deletion confers very high risk of inhibitor development in three related severe haemophiliacs

Haemophilia A displays a broad heterogeneity of genetic defects and of clinical severity. Inhibitor development is the main complication of replacement therapy in severe cases and most patients with inhibitors have gross gene rearrangement or point mutations, which hamper the production of normal circulating factor VIII (FVIII). We have investigated three related severe haemophilia A patients, all of whom have high titre inhibitors. By using long-range polymerase chain reaction (PCR) for FVIII gene inversion, we observed an unusual pattern in these patients. We therefore decided to screen the whole FVIII gene by conformation-sensitive gel electrophoresis. A large FVIII gene deletion spanning exon 2 to exon 25 was identified and we were able to obtain a 18.5 kb PCR product, which is specific for this mutation and useful for determining the carrier state in this family. All three haemophiliacs carrying this very large gene deletion show similar clinical history and very high-titre inhibitors, supporting the observation that inhibitor development seems to be an inherited characteristic. On the basis of our observations we think that this subgroup of patients at very high risk of inhibitor development should be identified by mutation analysis whenever possible, before the beginning of replacement therapy.

Attachment of A-431 cells on immobilized antibodies to the EGF receptor promotes cell spreading and reorganization of the microfilament system

EGF-like sequences, inherent in a number of extracellular matrix proteins, participate in cell adhesion. It is possible that interactions of these sequences with EGF receptors (EGFR) affect actin filament organization. It was shown previously [Khrebtukova et al., 1991: Exp. Cell Res. 194:48-55] that antibodies specific to EGFR induce capping of these receptors and redistribution of cytoskeletal proteins in A-431 cells. Here we report that A-431 cells attach and spread on solid substrata coated with antibodies to EGFR, even in the absence of serum. Thus, EGFR can act as an adhesion protein and promote microfilament reorganization. Binding of the cells to the EGFR-antibody resulted in the formation of a unique cell shape characterized by numerous, actin-based filopodia radiating from the cell body, but without membrane ruffles. There was also a conspicuous circular belt of actin-containing fibers inside the cell margin, and many irregular actin aggregates in the perinuclear area. The morphologies and actin distributions in A-431 cells spread on fibronectin or laminin 2/4 were very different. On fibronectin, cells had polygonal shapes with numerous stress-fibers and thick actin-containing fibers along the cell edges. On laminin-covered substrata, the cells became fusiform and acquired broad leading lamellae with ruffles. In these cells, there were also a few bundles of filaments running the whole length of the cell body, and shorter bundles extending through the leading lamellae towards the membrane ruffles in the cell edge. These effects and those seen with immobilized EGF suggest that different ligand/receptor complexes induce specific reorganizations of the microfilament system.

Experience of a single Italian center in genetic counseling for hemophilia: from linkage analysis to molecular diagnosis

BACKGROUND AND OBJECTIVE

We describe our three year experience in genetic counseling at the Castelfranco Veneto Hemophilia Center, Italy.

DESIGN AND METHODS

A total of 258 individuals were involved in the study of 142 females. These formed 40 families with hemophilia A and 6 families with hemophilia B. Following pedigree analysis, the FVIII inversion was first examined in severe hemophilia A patients by polymerase chain reaction (PCR) analysis. DNA polymorphisms were used to track the affected gene through the remaining families. In uninformative cases, we initiated analysis of the FVIII or FIX gene coding region by conformation sensitive gel electrophoresis and DNA sequencing to identify the mutation responsible for the disease.

RESULTS

The FVIII gene inversion was present in 16 of the 32 patients (50%) affected by severe hemophilia A and was informative for 44 females. For hemophilia A, 45 cases (55%) were informative by linkage analysis, however 37 (45%) were uninformative because of lack of key individuals, homozygosity, or sporadic disease. Information from extragenic linked polymorphisms alone was present in 9 cases (6%). For hemophilia B, linkage analysis was informative in only 50% of females (8 out of 16). To date, nine mutations have been identified in patients with hemophilia A and three in patients with hemophilia B. Six novel missense mutations in hemophilia A are discussed briefly.

INTERPRETATION AND CONCLUSIONS

Using this approach we are now able to offer accurate genetic analysis to virtually all families with hemophilia.