Prediction of Synergistic Toxicity of Binary Mixtures to Vibrio fischeri Based on Biomolecular Interaction Networks.

The paradigm of chemical safety assessment is shifting from 'chemical management focusing on single chemicals' to 'product management extending to mixtures and articles'. However, because of the enormous combinatorial complexity, testing the toxicity of all conceivable mixture products is currently not feasible. There exist only few models that allow predicting the synergistic toxicity potentially caused by toxicological interactions among components.

Folliculocentric cutaneous presentation of disseminated Candida krusei infection in a patient with acute myeloid leukemia.

Candida krusei (C. krusei) is a multidrug-resistant opportunistic fungal pathogen that may cause disseminated infections in immunocompromised hosts. However, its clinical and histologic features are not well-characterized.

Anetoderma secondary to antiphospholipid antibodies.

Anetoderma is an elastolytic disorder that is associated with a number of infectious and autoimmune disorders. We present a case of a patient with generalized anetoderma, who was later found to have positive antinuclear antibodies and antiphospholipid antibodies (APAs). Numerous other cases have been reported in literature and some authors have suggested that anetoderma is a highly specific sign of APAs, with or without other manifestations of systemic lupus erythematosus or antiphospholipid syndrome [14].

Diffuse large B-cell lymphoma.

We present a 56-year-old man with a two-year history of erythematous nodules and plaques on the forehead, frontal aspect of the scalp, and left side of the neck. Histopathologic findings are compatible with a diagnosis of diffuse large B-cell lymphoma (DLBCL). We present a brief review of primary cutaneous DLBCLs and address the putative association between DLBCLs and hepatitis C virus infection.

Disseminated superficial actinic porokeratosis.

Disseminated superficial actinic porokeratosis, which was described in 1966, is characterized by small, atrophic patches with distinctive keratin rims that occur on sun-exposed areas of the extremities, shoulders, and back. The diagnosis is based on the histopathologic finding of a cornoid lamella, absence of a granular layer, and often a thin epidermis. It is associated with exposure to ultraviolet radiation.

Papular variant of annular elastolytic giant-cell granuloma.

A 53-year-old woman presented with a six-month history of non-pruritic, erythematous papules and papular-plaques that were localized to the anterior and lateral aspects of the neck. A biopsy specimen showed elastolysis and granuloma formation, which were consistent with a diagnosis of annular elastolytic giant-cell granuloma. This is one of the few reported cases of this entity that consists predominantly of papular lesions rather than annular plaques.

Linear morphea of the forehead (en coup de sabre).

Linear morphea of the forehead or en coup de sabre (ECDS) is an unusual variant of morphea. It typically occurs in children although cases of adult-onset ECDS exist as reported here. ECDS has a specific distribution on the frontal scalp and forehead and is usually unilateral.

Erythema annulare centrifugum.

Erythema annulare centrifugum (EAC) is a gyrate erythema, which is typically characterized by annular, erythematous plaques with trailing scale. It is considered to be a reactive condition with a wide variety of inciting causes but unclear pathophysiology. The mean duration of the eruption is 11 months.

Angiofibromas in multiple endocrine neoplasia type 1.

Multiple endocrine neoplasia type 1 (MEN1) is a familial tumor syndrome with autosomal dominant inheritance. Cutaneous tumors in MEN1, which include multiple angiofibromas, collagenomas, and lipomas can easily be overlooked because of their subtle appearance. As markers of this tumor syndrome, recognition of the mucocutaneous manifestations of MEN1 is important in order to facilitate early interdisciplinary care and diagnosis of associated internal disease in both patients and family members.

Localized pemphigus with vegetative features.

We present a 58-year-old Jamaican man with an eight-month history of an isolated, vegetative, eroded, and crusted plaque on the posterior aspect of the scalp. One month prior to referral to the Charles C. Harris Skin and Cancer Pavilion he developed a few, scattered erosions on the extremities.

Verrucous and macular sarcoidosis.

We present a case of cutaneous sarcoidosis in a 77-year-old woman without systemic disease, who presented with two subtypes of lesions: erythematous and hyperpigmented macules on the arms and anterior upper legs and erythematous, hyperkeratotic nodules, some crateriform, on the lower legs and feet. Whereas cutaneous sarcoidosis is present in up to one-third of cases and may present with a wide variety of lesions, verrucous sarcoidosis is uncommon. Diagnosis is by clinical and histopathologic exclusion of other entities, which include other causes of granulomatous inflammation such as infections and foreign-body reactions.

Verrucous lymphangioma circumscriptum.

A 19-year-old woman with a seven-year history of pruritic, grouped, verrucous papules and plaques on the left arm presented for consultation. The lesion slightly flattened in appearance with topical glucocorticoid treatment. The histopathological features were consistent with lymphangioma circumscriptum.

Dissecting cellulitis of the scalp.

Dissecting cellulitis of the scalp is a chronic, relapsing, inflammatory disease of the scalp that results in scarring alopecia. We present a case of a 32-year-old man with recalcitrant disease who is now responding to treatment with isotretinoin. The pathogenesis, clinical presentation, disease associations, and histopathological findings are reviewed.

Eruptive vellus hair cysts.

Eruptive vellus hair cyst (EVHC), described initially in 1977, is a benign dermatologic condition that is characterized by the sudden appearance of monomorphic, follicular, asymptomatic, small papules in children and young adults. The diagnosis is based on the histopathologic findings of stratified-squamous epithelium with a granular layer that surrounds a cystic space filled with laminated keratin and a variable number of vellus hair cysts. EVHC can be associated with steatocystoma multiplex.

Perifollicular Langerhans cell histiocytosis.

A 25-year-old man presented with a 13-year history of an erythematous, papular eruption of his face and trunk, which was treated in the past as acne and psoriasis with isotretinoin and methotrexate, respectively. Histopathologic examination demonstrated an infiltrate of Langerhans cells, which was consistent with Langerhans cell histiocytosis. The epidemiology, clinical presentation, and treatment options of this disease are reviewed.

Purpura annularis telangiectoides.

Purpura annularis telangiectoides of Majocchi (PATM) is a clinical variant of pigmented purpuric dermatoses. It is characterized by asymptomatic or mildly pruritic, erythematous, annular patches that vary in size. The patches exhibit central clearing and peripheral cayenne pepper petechiae.

Poikilodermatous mycosis fungoides.

Poikilodermatous mycosis fungoides (MF) is a variant of MF, formerly referred to as poikiloderma vasculare atrophicans. The lesions are classically characterized by large plaques of hypopigmentation and hyperpigmentation with atrophy and telangiectases. The plaques may be asymptomatic or mildly pruritic and typically involve the major flexural areas and trunk.

Hypergammaglobulinemic purpura of Waldenström.

We report a case of a 33-year-old-woman with a one-year history of bilateral lower extremity vasculitis and laboratory evidence of hypergammaglobulinemia with otherwise unremarkable routine laboratory and rheumatologic studies. Her clinical picture, together with histopathologic evidence of leukocytoclastic vasculitis, favor a diagnosis of hypergammaglobulinemic purpura of Waldenström.

Eruptive basal-cell carcinomas in the setting of human immunodeficiency virus infection.

Patients with human immunodeficiency virus are known to have an increased risk for development of cutaneous malignant conditions. We present a 55-year-old man with a history of an isolated squamous-cell carcinoma five years prior, who presented with 27 cutaneous lesions, which had developed over the course of the preceding year. This occurred in the context of a new diagnosis of human immunodeficiency virus (HIV) infection and acquired immune deficiency syndrome (AIDS).

Pseudoepitheliomatous hyperplasia and transepidermal elimination in lepromatous leprosy: does T-cell plasticity play a role?

Background: The longstanding concept of a Th1-Th2 dichotomy in leprosy, with Th1-predominant tuberculoid leprosy and Th2-predominant lepromatous leprosy (LL), has recently been challenged, and Cbl-b overexpression may emerge as an important factor in anergy and progression of LL. Moreover, Th17 and Th22 subsets have been identified as Th1-Th2 modulators in inflammatory skin diseases, most notably psoriasis, but their roles in leprosy have not yet been elucidated. The occurrence of pseudoepitheliomatous hyperplasia (PEH) with transepidermal elimination of mycobacteria in LL patients, which could theoretically be a portal for contact transmission, thus raises important immunological questions: Do Th17 and/or Th22 subsets mediate epidermal proliferation akin to Th1-driven psoriasis in supposedly Th2-predominant LL disease, and is the Th1-Th2 immunostat set systemically or locally? Furthermore, which microRNAs (miRs), signal transducers, and activators of transcription (STAT) proteins regulate this transition in leprosy, if any, and does differential Cb1-b expression play a role?

Observation: A 71-year-old man presented with an infiltrative dermopathy characteristic of LL, as well as several hyperkeratotic plaques.