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. The majority of cases are benign with a low risk of metastasis. The size of such growths is variable with reported cases ranging from 5.0cm×5.0cm to as large as 20.0cm×14.0cm. Treatment options include surgical excision, oral retinoids, and intralesional chemotherapeutics such as methotrexate or bleomycin. We herein present a case of KCM manifesting as an exophytic, crateriform plaque in a 61-year-old man.

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. Pedunculated lesions, however, are rarely described in the literature. We present two cases of atypical fibroxanthoma manifesting as exophytic, pedunculated lesions on the face: one in a 74-year-old man and the other in an 82-year-old woman. These tumors are very effectively treated by excision with Mohs micrographic surgery.

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. Biopsy revealed a dense dermal infiltrate of neutrophils with negative tissue cultures consistent with pyoderma gangrenosum (PG). He was treated with systemic, intralesional, and topical steroids, as well as doxycycline. Three weeks after the diagnosis of PG, he was found to have persistent anemia and leukopenia. Bone marrow aspiration analysis was consistent with hypocellular myelodysplastic syndrome and genetic testing was consistent with Fanconi anemia. There is a well-known association of PG with hematological disorders. Fanconi anemia is a rare genetic hematologic disorder with congenital defects leading to bone marrow failure and malignancy in long-standing disease. In our patient, we consider his development of PG a paraneoplastic sign associated with the onset of his hypocellular myelodysplastic syndrome.

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. OBJECTIVE: To study the natural history of chronic actinic dermatitis in patients in the United States. METHODS: We performed a retrospective chart review and telephone questionnaire after a 3- to 19-year follow-up period. RESULTS: Of 20 patients with chronic actinic dermatitis, 7 patients (35%) experienced resolution and an additional 11 patients (55%) experienced improvement of their photosensitivity to sunlight during the follow-up period. The proportion of patients experiencing improvement or resolution of their chronic actinic dermatitis increased at 5, 10, and 15 years after diagnosis. CONCLUSIONS: Our study demonstrates that abnormal photosensitivity to sunlight in chronic actinic dermatitis improves or resolves over time in most patients in New York. The rates of improvement or resolution in our patients in New York are similar to the rates in case series in Europe despite likely patient demographic differences.

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. A retrospective chart review was conducted in patients with positive photopatch test reactions to fentichlor at our institution. Product inquiries were placed to manufacturers of fentichlor to elicit the current uses of fentichlor. RESULTS: In selected photopatch test studies, positive reactions to fentichlor occurred in 0.0% to 11.8% of subjects. We found that 25 companies distribute or manufacture fentichlor worldwide, which includes 2 companies that sell 25-kg drums of fentichlor. The most common current uses of fentichlor are in research, in high throughput screening, and in antibacterial and antifungal creams. CONCLUSIONS: Our review of selected photopatch test studies demonstrates that fentichlor remains a potent photosensitizing allergen worldwide. The bulk quantities of fentichlor available for sale and the current uses of fentichlor suggest that fentichlor may be currently incorporated into consumer products. We recommend that fentichlor remain in the standard series of photopatch test allergens.

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. The current studies use a human PAF-receptor (PAF-R) negative epithelial cell line transduced with PAF-Rs and PAF-R-deficient mice to demonstrate that activation of the epidermal PAF-R along with UVB irradiation results in a synergistic production of TNF-alpha. It should be noted that PAF-R effects are mimicked by the protein kinase C (PKC) agonist phorbol myristic acetate, and are inhibited by pharmacological antagonists of the PKC gamma isoenzyme. These studies suggest that concomitant PAF-R activation and UVB irradiation results in a synergistic production of the cytokine TNF-alpha which is mediated in part via PKC. These studies provide a novel potential mechanism for photosensitivity responses.

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. UVB irradiation of human epidermal KB cells resulted in both increased levels of reactive oxygen species (ROS) and PAF-R agonistic activity. Pretreatment of KB cells with antioxidants vitamin C and N-acetylcysteine or the pharmacological inhibitor PD168393 specific for the epidermal growth factor receptor all inhibited UVB-induced ROS as well as PAF-R agonists, yet had no effect on fMLP-mediated PAF-R agonist production. In addition, in vivo production of PAF-R agonists from UVB-irradiated mouse skin was blocked by both systemic vitamin C administration and topical PD168393 application. Moreover, both vitamin C and PD168393 abolished UVB-mediated but not the PAF-R agonist 1-hexadecyl-2-N-methylcarbamoyl glycerophosphocholine-mediated immunosuppression as measured by the inhibition of delayed type contact hypersensitivity to the chemical dinitrofluorobenzene. These studies suggest that UVB-induced systemic immunosuppression is due to epidermal growth factor receptor-mediated ROS which results in PAF-R agonist formation.