[Tinea barbae profunda by Arthroderma benhamiae. A diagnostic challenge]

Dermatomycoses due to pets and farm animals are often a clinical and diagnostic challenge for dermatologists. A 24-year-old man presented with inflammatory skin changes on his cheeks and chin. Because of negative fungal culture and the clinical appearance of a highly inflammatory process, our first diagnosis was a bacterial pyoderma. Polymerase chain reaction (PCR) identified Arthroderma benhamiae in both the patient and his guinea pig. A. benhamiae is a zoophilic dermatophyte which belongs to the Trichophyton mentagrophytes-complex. The fungus is acquired from guinea pigs and causes highly inflammatory forms of tinea. PCR-based diagnostics are quick and simple tools to identify this pathogen, so that suitable antimycotic therapy can be initiated quickly.

[Metastatic malignant melanoma. Successfull treatment with ipilimumab]

A 73-year-old man, in whom 26 years ago a malignant melanoma with cervical lymph node metastases of the right retroauricular region was diagnosed, developed BRAF V600E-negative distant metastases, which progressed during both monochemotherapy and polychemotherapy. Therefore he was started on ipilimumab in a dose of 3 mg/kg body weight four times in intervals of 3 weeks. Subsequently, there was an almost complete regression of distant metastases. In several phase III trials a significant survival benefit has been identified for patients treated with ipilimumab. The human monoclonal antibody has been approved since July 2011 as a second-line treatment in Germany and was incorporated in January 2013 into the new guidelines for the treatment of malignant melanoma. The CTLA-4 antibody is the first drug that can improve significantly survival in patients with metastatic melanoma. In advanced (unresectable or metastatic) melanoma, immunostimulatory treatment with ipilimumab represents a new therapeutic option.

[Malassezia folliculitis in an immunocompromised patient]

Malassezia folliculitis (synonym: Pityrosporum folliculitis) is a polymorphic dermatomycosis characterized by the development of small papules and pustules. In severe cases, molluscoid comedonal papules are typical. The disease occurs mainly in sebum-rich areas of the face, back and chest, frequently affecting patients under immunosuppressive therapy. We report a case of Malassezia folliculitis observed in a heart transplant recipient who was successfully treated with itraconazole. Moreover, we summarize the taxonomy of the genus Malassezia as well as diagnostic and therapeutic measures of the related folliculitis.

[Infantile hemangioma. Successful treatment with propranolol]

We report on an infant, aged four months, suffering from a severe hemangioma of the left labium majus. We induced systemic treatment with propranolol in off-label-use over a period of 5 1/2 months. A few weeks after onset of the treatment, the size and color of hemangioma was obviously reduced; finally there was an almost complete regression. This result underlines the role of propranolol in treatment of problematic hemangioma.

The role of hematopoietic stem-cell transplantation in cutaneous T-cell lymphoma

Cutaneous T-cell lymphoma represents a broad spectrum of disorders with various manifestations, clinical courses, and therapeutic considerations. Mycosis fungoides is the most common form of cutaneous T-cell lymphoma, the skin being affected by erythematous patches, plaques, or tumors. The related Sézary syndrome is a more aggressive form of cutaneous T-cell lymphoma with cutaneous and leukemic manifestations. Recent advances in the understanding of the molecular and biologic behavior of T cells in these disorders have facilitated the development of novel treatments, using biologic agents, phototherapeutic methods, and irradiation techniques. Nevertheless, there remains a continued need to develop new therapeutic options, particularly for patients with advanced-stage and treatment-refractory disease. At present, hematopoietic stem-cell transplantation has the best chance for expanding the therapeutic armamentarium of cutaneous T-cell lymphoma. In advanced-stage mycosis fungoides and the Sézary syndrome, stem cell transplantation may result in sustained remissions and improvement of progression-free survival. However, physicians have to be aware of severe clinical problems like graft-versus-host disease as well as increased risk of infection and secondary cancers. In this review, we focus on the role of hematopoietic stem cell transplantation for the therapy of mycosis fungoides and the Sézary syndrome.

[Langerhans cell histiocytosis. Solitary facial lesion]

Langerhans cell histiocytosis is the general term for all clinical entities characterized by a proliferation of dendritic cells that are phenotypically identical to the Langerhans cells of the skin. As dendritic cells are present in nearly every tissue of the body, Langerhans cell histiocytosis shows a broad spectrum of clinical manifestations, mostly in the bone (approximately 80%) and skin (approximately 60%). Langerhans cell histiocytosis is basically a disease of the childhood and early youth, but can rarely occur in the elderly. Here, we report on a 70-year-old man presenting with a single facial lesion of Langerhans cell histiocytosis and summarize the most important clinical aspects as well as current therapeutic concepts.

[Merkel cell carcinoma. Viral genesis and new therapeutic options?]

Merkel cell carcinoma (cutaneous neuroendocrine carcinoma) is a rare, highly malignant, neuroendocrine tumor of the skin with predominance in older patients. The tumor is most often located in the sun-exposed skin of the head, the neck and -as in our patient - the extremities. Notably, the tumor bears a high risk of an early regional lymph node as well as distant metastases. Clinically, only a presumptive diagnosis of Merkel cell carcinoma can be established. The definite diagnosis is made by histological and immunohistological methods. Surgical excision with a safety margin should be combined with sentinel lymph node biopsy. In advanced tumor stages (lymph node or visceral metastasis), a remission can be achieved by different chemotherapy schedules in combination with radiation. Recently, a previously unknown polyomavirus, named Merkel cell polyomavirus (MCV or MCPyV), has been identified in 80% of Merkel cell carcinomas. In the near future, these novel findings could be utilized to distinguish Merkel cell carcinoma from small round cell cancers and could lead to the development of new therapeutic options.

[Tuberous sclerosis: diagnostic criteria and new treatment approaches]

With a prevalence of 1 in 6,000 births, tuberous sclerosis is a relatively frequent hamartoma and tumor syndrome inherited as an autosomal dominant trait, which manifests primarily on the skin and in the central nervous system. Decisive factors for morbidity and mortality and thus for the prognosis are the changes in the central nervous system in the form of cortical hamartomas. Treatment for many years consisted solely in using nonspecific symptomatic approaches; dermatological therapy comprised mainly laser or electroacoustic ablation of facial angiofibromas. New models of therapy hinder the pathogenesis of tuberous sclerosis. Various studies provided evidence that the macrolide rapamycin decreases growth of brain and kidney tumors by specific inhibition of mTOR kinase. Synergistic effects were observed in combination therapy with the cytokine IFN-gamma.

Ultraviolet A1 radiation induces nitric oxide synthase-2 expression in human skin endothelial cells in the absence of proinflammatory cytokines

Skin exposure to ultraviolet radiation from sunlight causes erythema and edema formation as well as inflammatory responses. As some of these ultraviolet-induced effects are potentially mediated by nitric oxide synthases, we examined the role of cytokines and ultraviolet A1 radiation (340-400 nm) on the expression of the nitric oxide synthase-2 in endothelia of normal human skin biopsies during short-term organ culture as well as expression and activity of the nitric oxide synthase-2 in in vitro cell cultures of human dermal endothelial cells. Both, cytokine challenge (interleukin-1beta + tumor necrosis factor-alpha + interferon-gamma) but also ultraviolet A1 exposure (50 J per cm2) in the absence of cytokines led to the expression of nitric oxide synthase-2 in human skin organ cultures as shown by immunohistochemistry. Moreover, exposing human dermal endothelial cell cultures to proinflammatory cytokines but also to ultraviolet A1 radiation (6-24 J per cm2) in the absence of cytokines resulted in significant nitric oxide synthase-2 mRNA and protein expression as well as enzyme activity. Ultraviolet A1 irradiation of cytokine activated cells led to further increases in nitric oxide synthase-2 mRNA, protein expression, and enzyme activity. Moreover, a reporter gene assay using a human nitric oxide synthase-2 promoter construct provide evidence that ultraviolet A1, in the absence of cytokines, induces nitric oxide synthase-2 expression and activity, as previously shown for cytokines. Thus, the results presented here demonstrate for the first time that in dermal endothelia of human skin ultraviolet A1 radiation alone represents a proinflammatory stimulus sufficient to initiate nitric oxide synthase-2 expression as well as activity comparable with the respective response seen in the presence of proinflammatory cytokines.

Even after UVA-exposure will nitric oxide protect cells from reactive oxygen intermediate-mediated apoptosis and necrosis

Reactive oxygen species (ROS) play a pivotal role in UVA-induced cell damage. As expression of the inducible nitric oxide synthase (iNOS) is a normal response of human skin to UV radiation we examined the role of nitric oxide (NO) as a protective agent during or even after UVA1- or ROS-exposure against apoptosis or necrosis of rat endothelial cells. When added during or up to 2 h subsequent to UVA1 or ROS exposure the NO-donor S-nitroso-cysteine (SNOC) at concentrations from 100-1000 microM significantly protects from both apoptosis as well as necrosis. The NO-mediated protection strongly correlates with complete inhibition of lipid peroxidation (sixfold increase of malonedialdehyde formation in untreated versus 1.2-fold with 1 mM SNOC). NO-mediated protection of membrane function was also shown by the inhibition of cytochrome c leakage in UVA1 treated cells, a process not accompanied by alterations in Bax and Bcl-2 protein levels. Thus, the experiments presented demonstrate that NO exposure during or even after a ROS-mediated toxic insult fully protects from apoptosis or necrosis by maintaining membrane integrity and function.