Ronni Wolf

Bullous pemphigoid: Etiology, pathogenesis, and inducing factors: Facts and controversies

The term pemphigoids includes a group of autoimmune bullous diseases characterized by subepidermal blistering. Bullous pemphigoid (BP) is not only the most common disorder within the pemphigoid group, but also represents the most frequent autoimmune blistering disease in general. The onset and course of BP depend on a variable interaction between predisposing and inducing factors. HLA genes are the most significant genetic predisposition factor to autoimmunity mechanisms. Many studies show an association between HLA-DQβ1*0301 and distinct clinical pemphigoid variants. Imbalance between autoreactive T helper (Th) and T regulatory cells, toll-like receptor activation, and Th17/IL-17 pathway are the three possible autoimmunity triggers underlying BP. The pathomechanism of BP hinges on an autoantibody response toward structural components of the hemidesmosome (BP180 and BP230). The binding of autoantibodies leads to complement activation, recruitment of inflammatory cells, and release of proteolytic enzymes. The inflammatory cascade also may be directly triggered by activation of Th17 cells with no intervention of autoantibodies. The intervention of inducing factors in BP can be identified in no more than 15% of patients. Facilitating factors in genetically predisposed individuals are various (drug intake, physical agents, and viral infections). Drugs may act as triggers by either modifying the immune response or altering the antigenic properties of the epidermal basement membrane. Cases of induction of BP by physical agents (eg, radiation therapy, ultraviolet radiation, thermal or electrical burns, surgical procedures, transplants) are rare, but well-documented events. A contributing role in inducing BP has been suggested for infections, in particular human herpes virus (HHV) infections (cytomegalovirus, Epstein-Barr virus, and HHV-6), but also hepatitis B and C viruses, Helicobacter pylori, and Toxoplasma gondii. Unlike pemphigus, no dietary triggers have been suspected of being involved in the induction of BP. In all patients who have a diagnosis of BP, an environmental agent as a potential cause should always be considered, because the prompt discontinuation of it might result in rapid improvement or even cure of the disease.

Pemphigus: Etiology, pathogenesis, and inducing or triggering factors: Facts and controversies

Pemphigus includes a group of autoimmune bullous diseases with intraepithelial lesions involving the skin and Malpighian mucous membranes. Pemphigus vulgaris (PV), the most frequent and representative form of the group, is a prototypical organ-specific human autoimmune disorder with a poor prognosis in the absence of medical treatment. The pathomechanism of PV hinges on autoantibodies damaging cell-cell cohesion and leading to cell-cell detachment (acantholysis) of the epidermis and Malpighian mucosae (mainly oral mucosa). A controversy exists about which subset of autoantibodies is primarily pathogenic: the desmoglein-reactive antibodies or those directed against the acetylcholine receptors of the keratinocyte membrane. The onset and course of PV depend on a variable interaction between predisposing and inducing factors. Genetic predisposition has a complex polygenic basis, involving multiple genetic loci; however, the genetic background alone (the soil), although essential, is not by itself sufficient to initiate the autoimmune mechanism, as proven by the reports of PV in only one of two monozygotic twins and in only two of three siblings with an identical PV-prone haplotype. The intervention of inducing or triggering environmental factors (the seed) seems to be crucial to set off the disease. The precipitating factors are many and various, most of them directly originating from the environment (eg, drug intake, viral infections, physical agents, contact allergens, diet), others being endogenous (eg, emotional stress, hormonal disorders) but somehow linked with the subjects lifestyle. As to certain drugs, their potential of provoking acantholysis may be implemented by their interfering with the keratinocyte membrane biochemistry (biochemical acantholysis) and/or with the immune balance (immunologic acantholysis). Viral infections, especially the herpetic ones, may trigger the outbreak of PV or simply complicate its clinical course. The precipitating effect might be due to interferons and other cytokines released by the host as a consequence of the viral attack, which overactivate the immune response. Inductions of PV by physical agents (ultraviolet or ionizing radiation, thermal or electrical burns, surgery and cosmetic procedures), contact allergens (in particular, organophosphate pesticides), dietary factors (eg, garlic, leek, onion, black pepper, red chili pepper, red wine, tea), and emotional stress are rare, but well-documented events. The possible intervention of the environment in the outbreak of PV has been overlooked in the past, but nowadays clinicians perceive it more frequently. The assumption that genetic factors alone are not sufficient to cause the outbreak of the disease, inevitably instills the idea that PV may not occur spontaneously, but always results from an interaction between an individual predisposing genetic background and environmental precipitating factors, often concealed or apparently harmless.

Pemphigus: Associations and management guidelines: Facts and controversies

Pemphigus, a prototypical organ-specific human autoimmune disease, may be associated with other immunity-related disorders, viral infections, and different types of tumors. Coexistence with immune diseases is fairly frequent and, for some of them (eg, myasthenia gravis, Basedows disease, rheumatoid arthritis, or lupus erythematosus), common pathogenic mechanisms can be considered. The association with viral infections (mainly herpesvirus infections) raises the question of whether the virus triggers the outbreak of the disease or simply complicates its clinical course. Neoplastic proliferations coexisting with pemphigus have a different histogenesis and the pathogenic link may vary according to the associated tumor (thymoma, lymphoma, carcinoma, or sarcoma). A subset of pemphigus-neoplasia association is represented by Anhalts paraneoplastic pemphigus, with peculiar clinical, histologic, and immunologic features characterizing it. Coexistence of pemphigus with Kaposis sarcoma, albeit not frequent, offers an intriguing speculative interest. The cornerstone of management in pemphigus is the combination of systemic corticosteroids and immunosuppressants. The conventional treatment used in most cases is based on oral administration of deflazacort and azathioprine. In selected cases, mycophenolate mofetil is preferred to azathioprine. Severe forms of pemphigus require intravenous pulse therapy with dexamethasone (or methylprednisolone) and cyclophosphamide. In the recent years, the use of high-dose intravenous immunoglobulin therapy has gained several consents. Rituximab, a monoclonal anti-CD 20 antibody, which affects both the humoral and cell-mediated responses, has proved to give a good clinical response, often paralleled by decrease of pathogenic autoantibodies. The combination with intravenous immunoglobulin offers the double advantage of better clinical results and a reduced incidence of infection. Interventional treatments, such as plasmapheresis and extracorporeal immunoadsorption, are aimed at patients with life-threatening forms of pemphigus and high levels of circulating autoantibodies, a circumstance where the medical therapy alone risks failing. Second-line treatments include gold salts (which we do not favor because of the acantholytic potential inherent in thiol structure) and the association of oral tetracyclines with nicotinamide, which is rather safe. Local treatments, supplementary to the systemic therapy, are aimed at preventing infections and stimulating reepithelialization of eroded areas. Innovative topical treatments are epidermal growth factor, nicotinamide gel, pimecrolimus, and a proteomics-derived desmoglein peptide. Pemphigus patients should be warned against over-indulging in unnecessary drug intake, prolonged exposure to ultraviolet rays, intense emotional stress, and too spiced or too hot foods. Cigarette smoking is not contraindicated in pemphigus patients because of the nicotine anti-acantholytic properties.

Kaposi’s sarcoma: Etiology and pathogenesis, inducing factors, causal associations, and treatments: Facts and controversies

n Abstractn n Kaposis sarcoma (KS), an angioproliferative disorder, has a viral etiology and a multifactorial pathogenesis hinged on an immune dysfunction. The disease is multifocal, with a course ranging from indolent, with only skin manifestations to fulminant, with extensive visceral involvement. In the current view, all forms of KS have a common etiology in human herpesvirus (HHV)-8 infection, and the differences among them are due to the involvement of various cofactors. In fact, HHV-8 infection can be considered a necessary but not sufficient condition for the development of KS, because further factors (genetic, immunologic, and environmental) are required. The role of cofactors can be attributed to their ability to interact with HHV-8, to affect the immune system, or to act as vasoactive agents. In this contribution, a survey of the current state of knowledge on many and various factors involved in KS pathogenesis is carried out, in particular by highlighting the facts and controversies about the role of some drugs (quinine analogues and angiotensin-converting enzyme inhibitors) in the onset of the disease. Based on these assessments, it is possible to hypothesize that the role of cofactors in KS pathogenesis can move toward an effect either favoring or inhibiting the onset of the disease, depending on the presence of other agents modulating the pathogenesis itself, such as genetic predisposition, environmental factors, drug intake, or lymph flow disorders. It is possible that the same agents may act as either stimulating or inhibiting cofactors according to the patient’s genetic background and variable interactions.n Treatment guidelines for each form of KS are outlined, because a unique standard therapy for all of them cannot be considered due to KS heterogeneity. In most cases, therapeutic options, both local and systemic, should be tailored to the patient’s peculiar clinical conditions.n n

Rosacea and rhinophyma

Rosacea is a common and chronic inflammatory cutaneous disease with unknown etiology. The pathophysiology of rosacea is still poorly understood. Epidemiological studies indicate a genetic component, but a rosacea gene has not been detected yet. Recent molecular studies propose that an altered innate immune response is involved in the pathogenesis of the rosacea disease. Signs of rosacea are indicated by the presence of characteristic facial or ocular inflammation involving both the vascular and tissue stroma. A wide range of drug options is available for the treatment of rosacea, including several topical ones (metronidazole, antibiotics, azelaic acid, benzoyl peroxide, sulfacetamide/sulfur, retinoids) and oral ones (mainly tetracyclines, metronidazole, macrolides, isotretinoin). This review highlights the recent clinical and pathophysiological developments concerning rosacea.

Bullous pemphigoid: associations and management guidelines: facts and controversies.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal).nnThis article has been retracted at the request of the Editor following the discovery that the text overlaps significantly with sections of several articles that are cited in the reference section, including the following:nnCulton DA, Diaz LA. Treatment of subepidermal immunobullous diseases. Clin Dermatol 2012;30:95–102.nnMeurer M. Immunosuppressive therapy for autoimmune bullous diseases. Clin Dermatol 2012;30:78–83.nnLjubojevic S, Lipozencic J. Autoimmune bullous diseases associations. Clin Dermatol 2012;30:17–33.nnSehgal VN, Verma. Leflunomide: dermatologic perspective. J Dermatolog Treat 2013;24:89–95.nnGürcan HM, Ahmed AR. Analysis of current data on the use of methotrexate in the treatment of pemphigus and pemphigoid. Br J Dermatol 2009;16:723–31.nnChen YJ, Wu CY, Lin MW, et al. Comorbidity profiles among patients with bullous pemphigoid: a nationwide population-based study. Br J Dermatol 2011;165:593–9

Contact dermatitis: Facts and controversies

The history of contact dermatitis (CD) is inseparable from the history of the patch test, and the patch test is inseparable from the pioneer in the field, Josef Jadassohn (1860-1936). Despite the fact that we have been diagnosing, treating, and investigating the condition for more than 100 years, there are still many unsolved questions and controversies, which show no signs of coming to an end in the foreseeable future. This contribution reviews and highlights some of the disagreements and discrepancies associated with CD. For example: • What is the real sensitizer in balsam of Peru, one of the most common allergens, and what, if any, is the value of a low-balsam diet? • Is benzalkonium chloride, which has well-known and undisputed irritant properties, a contact allergen as well? • Is cocamidopropyl betaine (CABP) a common contact allergen and what is the actual sensitizer in CABP allergy the molecule itself, or impurities, or intermediaries in its synthesis? • How can the significant differences in the prevalence of sensitization of formaldehyde (FA, a common cause of contact allergy) between the United States (8%-9%) and Europe (2%-3%) be explained? • What is the relationship between formaldehyde releasers (FRs) allergy and an FA allergy? Should we recommend that FA-allergic patients also avoid FRs, and, if so, to what extent? • What is the true frequency of lanolin allergy? This issue remains enigmatic despite the expenditure of thousands of dollars and the innumerable hours spent investigating this subject. • What is the basis behind the so-called lanolin paradox? This label was coined in 1996 and is still a matter of controversy. • Is there such a thing as systemic CD from nickel, and, if so, to what extent? Is there a cross-reactivity or concomitant sensitization between nickel and cobalt?These are some of the controversial problems discussed. We have selected the ones that we consider to be of special interest and importance to the practicing dermatologist.

Neutrophilic dermatosis of the hands after influenza vaccination

An otherwise healthy 72‐year‐old man presented with a painful eruption composed of grouped hemorrhagic purulent blisters on erythematous plaques, on both palms of his hands, which appeared 12 h after he had been vaccinated against influenza.

Diaper (napkin) dermatitis: A fold (intertriginous) dermatosis

Diaper (napkin) dermatitis is an acutely presenting inflammatory irritant contact dermatitis of the diaper region. It is one of the most common dermatologic diseases in infants and children. In the past, the disease was thought to be caused by ammonia; however, a number of factors, such as friction, wetness, inappropriate skin care, microorganisms, antibiotics, and nutritional defects, are important. Diaper dermatitis commonly affects the lower parts of the abdomen, thighs, and diaper area. Involvement of skin fold regions is typical with diaper dermatitis. At the early stages of the disease, only dryness is observed in the affected area. At later stages, erythematous maceration and edema can be seen. Secondary candidal and bacterial infections can complicate the dermatitis. In the differential diagnosis of the disease, allergic contact dermatitis, intertrigo, psoriasis, atopic and seborrheic dermatitis, and the other diseases should be considered. Causes of the disease should be determined and eliminated primarily. Families need to be informed about the importance of a clean, dry diaper area and the frequency of diaper changes. The use of superabsorbent disposable diapers has decreased the incidence of the disease. Soap and alcohol-containing products should be avoided in cleaning the area. In some cases, corticosteroids and antifungal agents can be administered. If necessary, antibacterial agents and calcineurin inhibitors can also be beneficial.

Periorbital (eyelid) dermatides.

Physicians in various specialties-and dermatologists in particular-frequently encounter various forms of inflammation of the eyelids and of the anterior surface of the eye. Distinguishing the cause of itchy, painful, red, edematous eyelids is often difficult. Because the uppermost layer of the eyelids is part of the skin that wraps the entire body, almost every skin disease in the textbook can affect the periorbital area as well. In this contribution, we focused on the most common such disorders that require special consideration, as a result of their special appearance, their challenging diagnosis, or the nature of their treatment. We reviewed the key features of several common dermatides that affect the eyelids, such as atopic dermatitis, seborrheic dermatitis, allergic contact dermatitis, airborne contact dermatitis, rosacea, psoriasis, and others. We focused on the special clinical features, causes, and treatments specific to the delicate skin of the eyelids. Because structures of the eye itself (i.e., the conjunctiva, the cornea, the lens, and the retina) may be involved in some of the discussed periorbital skin diseases, we found it useful to add a brief summary of the eyelid complications of those diseases. We then briefly reviewed some acute sight-threatening and even life-threatening infections of the eyelids, although dermatologists are not likely to be the primary care physicians responsible for treating them.