Keratoacanthoma centrifugum marginatum.

Keratoacanthoma centrifugum marginatum (KCM) is an uncommon variant of keratoacanthoma. Keratoacanthoma centrifugum marginatums are most commonly seen on sun-exposed surfaces and present with progressive peripheral expansion and raised, hyperkeratotic borders. Central clearing with atrophy and lack of spontaneous clearance are other key clinical characteristics.

Pedunculated atypical fibroxanthomas of the face.

Atypical fibroxanthomas are rare, superficial dermal tumors. Most cases are benign and only locally destructive with a low rate of metastasis. Lesions are most commonly found on sun-exposed sites of elderly light-skinned patients and present as asymptomatic nodules with irregular borders; ulcerations and friability are other key characteristics.

Pyoderma gangrenosum: a presenting sign of myelodysplastic syndrome in undiagnosed Fanconi anemia.

A 26-year-old man with a history of congenital bilateral microtia, unilateral renal agenesis, left aural atresia, and right external auditory canal occlusion admitted for right rib cartilage graft harvest and left ear re-construction. Following surgery, an ulceration with violaceous borders and a yellow fibrinous base unresponsive to broad-spectrum antibiotics developed at the harvest site. The wound was expanding and not responsive to systemic broad-spectrum antibiotics.

The natural history of chronic actinic dermatitis: an analysis at a single institution in the United States.

Background: Chronic actinic dermatitis is a photosensitivity disorder with scant epidemiologic data. Case series in Europe have previously shown that improvement or resolution of chronic actinic dermatitis occurs over time in most patients. However, the natural history of chronic actinic dermatitis in patients in the United States has not been studied.

Fentichlor photocontact dermatitis: a persistent enigma.

Background: Fentichlor elicits high rates of positive photopatch test reactions despite its currently unknown clinical relevance.

Objectives: The aims of this study were to provide a comprehensive review of fentichlor, to investigate the characteristics of patients with photosensitivity to fentichlor, and to explore the current uses of fentichlor.

Methods: A review of photopatch test studies involving fentichlor was performed.

Epidermal platelet-activating factor receptor activation and ultraviolet B radiation result in synergistic tumor necrosis factor-alpha production.

Ultraviolet B radiation (UVB) is a potent stimulator of epidermal cytokine production which has been implicated in photoaggravated dermatoses. In addition to cytokines such as tumor necrosis factor-alpha (TNF-alpha), UVB generates bioactive lipids including platelet-activating factor (PAF). Our previous studies have demonstrated that UVB-mediated production of keratinocyte TNF-alpha is in part due to PAF.

Ultraviolet B radiation generated platelet-activating factor receptor agonist formation involves EGF-R-mediated reactive oxygen species.

Recent studies have implicated the lipid mediator platelet-activating factor (PAF) in UVB-mediated systemic immunosuppression known to be a major cause for skin cancers. Previously, our group has demonstrated that UVB irradiation triggers the production of PAF and oxidized glycerophosphocholines that act as PAF-receptor (PAF-R) agonists. The present studies explored the mechanisms by which UVB generates PAF-R agonists.