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Open Access Publications from the University of California

Dermatology Online Journal

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Dermatology Online Journal is an open-access, refereed publication intended to meet reference and education needs of the international dermatology community since 1995. Dermatology Online Journal is supported by the Department of Dermatology UC Davis, and by the Northern California Veterans Administration.

Volume 20, Issue 6, 2014


Metabolomic analysis using porcine skin: a pilot study of analytical techniques

Background: Metabolic byproducts serve as indicators of the chemical processes and can provide valuable information on pathogenesis by measuring the amplified output. Standardized techniques for metabolome extraction of skin samples serve as a critical foundation to this field but have not been developed.

Objectives: We sought to determine the optimal cell lysage techniques for skin sample preparation and to compare GC-TOF-MS and UHPLC-QTOF-MS for metabolomic analysis.

Methods: Using porcine skin samples, we pulverized the skin via various combinations of mechanical techniques for cell lysage. After extraction, the samples were subjected to GC-TOF-MS and/or UHPLC-QTOF-MS.

Results: Signal intensities from GC-TOF-MS analysis showed that ultrasonication (2.7x107) was most effective for cell lysage when compared to mortar-and-pestle (2.6x107), ball mill followed by ultrasonication (1.6x107), mortar-and-pestle followed by ultrasonication (1.4x107), and homogenization (trial 1: 8.4x106; trial 2: 1.6x107). Due to the similar signal intensities, ultrasonication and mortar-and-pestle were applied to additional samples and subjected to GC-TOF-MS and UHPLC-QTOF-MS. Ultrasonication yielded greater signal intensities than mortar-and-pestle for 92% of detected metabolites following GC-TOF-MS and for 68% of detected metabolites following UHPLC-QTOF-MS.

Conclusion: Overall, ultrasonication is the preferred method for efficient cell lysage of skin tissue for both metabolomic platforms. With standardized sample preparation, metabolomic analysis of skin can serve as a powerful tool in elucidating underlying biological processes in dermatological conditions.

The economic burden of sunscreen usage

Excessive sun exposure is known to be the leading cause of skin cancer. The direct cellular damage inflicted by the ultraviolet (UV) radiation from the sun results in premature aging, DNA damage, and mutations that ultimately lead to skin cancer. Sunscreens are highly recommended to protect against UV radiation. However, little research has been conducted on the economic burden of sunscreen use. In this study, we aimed to evaluate the annual cost of sunscreen under both ideal and actual use conditions while stratifying for the sun protection factor (SPF) and by the name brand or equivalent store brand sunscreen. Pricing data was collected for sunscreens of SPF 30, 50, 70, and 100. For each type of sunscreen, the size and price of the container were recorded. Our results demonstrated that sunscreen prices increased with SPF but purchasing a generic sunscreen resulted in savings of 40%-50%. Our estimates reveal that sunscreens are affordable with annual expenditures ranging from $30.21 to $61.94, depending on brand, for SPF 50 sunscreens used with minimal application density for the average person.


Cantharidin: a comprehensive review of the clinical literature

Background: Cantharidin is a topical vesicant that causes intraepidermal acantholysis with clinical application that includes the removal of warts, molluscum contagiosum (MC), calluses, and acquired perforating dermatoses.

Objective: To provide a comprehensive literature review of the efficacy and safety of cantharidin in the management of various cutaneous conditions.

Methods: A PubMed search was conducted using the term “cantharidin” combined with “warts”, “plantar warts”, “verruca vulgaris”, “periungal”, “subungual”, “topical treatment”, “topical therapy for warts", molluscum contagiosum”, “perforating collagenosis,” and “acantholysis.”

Results: A total of 749 articles were identified and 37 articles met inclusion criteria for this review.  The majority of studies show that cantharidin is an effective and safe treatment for removal of warts and MC.  Several studies also show potential novel applications of cantharidin in acquired perforating dermatosis, acute herpes zoster, and leishmaniasis. Adverse effects are generally mild but common and should be monitored, particularly in the pediatric population.

Limitations: There is a paucity of high-powered clinical studies involving the use of cantharidin.

Conclusion: Topical cantharidin is a safe and effective treatment for warts, molluscum contagiosum, and callus removal, with promising uses in perforating dermatoses and leishmaniasis.


Dermatology on YouTube

YouTube, reaches upwards of six billion users on a monthly basis and is a unique source of information distribution and communication. Although the influence of YouTube on personal health decision-making is well established, this study assessed the type of content and viewership on a broad scope of dermatology related content on YouTube. Select terms (i.e. dermatology, sun protection, skin cancer, skin cancer awareness, and skin conditions) were searched on YouTube. Overall, the results included 100 videos with over 47 million viewers. Advocacy was the most prevalent content type at 24% of the total search results. These 100 videos were “shared” a total of 101,173 times and have driven 6,325 subscriptions to distinct YouTube user pages. Of the total videos, 35% were uploaded by or featured an MD/DO/PhD in dermatology or other specialty/field, 2% FNP/PA, 1% RN, and 62% other. As one of the most trafficked global sites on the Internet, YouTube is a valuable resource for dermatologists, physicians in other specialties, and the general public to share their dermatology-related content and gain subscribers. However, challenges of accessing and determining evidence-based data remain an issue.

Case Report

Primary cutaneous zygomycosis secondary to minor trauma in an immunocompromised pediatric patient: a case report

Zygomycosis is an opportunistic infection generally found in immunocompromised individuals. Herein we present a pediatric patient with primary cutaneous mucormycosis that developed at a site of trauma. Diagnosis and treatment are discussed.

Multimodal therapy of idiopathic pyoderma gangrenosum

A 13-year old girl was admitted to the University of California Davis Medical Center for evaluation and treatment of cutaneous bullae and ulcerations over her lower extremities that were refractory to antibiotic therapy and incision and drainage.  Her disease continued to worsen with the appearance of multiple new bullae and the progression of old ones into deep ulcers with undermined borders.  Biopsy revealed a neutrophilic dermatosis and diagnostic work-up was negative for infectious or autoimmune etiologies.  Given her clinical presentation, biopsy results, and negative work-up, a diagnosis of pyoderma gangrenosum (PG) was made and she was started on immunosuppressive medications.  The patient was started on a multidrug regimen of prednisone and cyclosporine but remission was not achieved until the addition of adalimumab.  After the inflammatory component of her disease was under control, wound care measures were maximized to promote ulcer healing.  Wound care measures included compression and debridement.  Upon complete closure of all wounds she was successfully transitioned to mycophenolate mofetil monotherapy for maintenance therapy.  This case emphasizes the need for combinational therapy to successfully treat severe cases of PG, which are often refractory to monotherapy with prednisone or cyclosporine.   It also highlights the importance of appropriate wound care to achieve complete ulcer healing.

Unilateral nevoid telangiectasia syndrome (UNTS) associated with chronic Hepatitis C virus and positive immunoreactivity for VEGF

Unilateral Nevoid Telangectasia Syndrome (UNTS) is characterized by superficial telangiectasias in a unilateral distribution. Vascular endothelial growth factor (VEGF) may play a role in the pathogenesis of UNTS in patients with underlying hepatic disease.  We report a case of a patient with UNTS accompanied by chronic hepatitis C virus infection, with a normal serum estrogen profile and strong positive immunohistochemical staining of lesional skin with VEGF.

Application of bimatoprost ophthalmic solution 0.03% for the treatment of eyebrow hypotrichosis: series of ten cases

In December 2008, bimatoprost ophthalmic solution 0.03% was approved in the United States for the treatment of hypotrichosis of the eyelashes. Since then, there have been several reports in the literature on the off-label use of bimatoprost ophthalmic solution 0.03% for the treatment of thinning in other hair bearing areas, such as in the eyebrows and in the scalp.  Herein, a prospective pilot study is presented in which bimatoprost ophthalmic solution 0.03% is evaluated for helping to re-grow hair in the eyebrow region of ten female patients.

Case Presentation

Cutaneous thrombogenic vasculopathy associated with bevacizumab therapy

Bevacizumab, a humanized monoclonal antibody against vascular endothelial growth factor (VEGF), is an angiogenesis inhibitor used to treat a variety of cancers, including lung, colon, cervical, ovarian, and renal cancers as well as glioblastoma.  A significant adverse effect associated with its use is one of thromboembolic events. We report a case of a 74-year-old male with diagnosis of glioblastoma multiforme treated with partial resection, radiation, temozolomide, and bevacizumab. He presented to a plastic surgeon with a several week history of asymptomatic crusted hemorrhagic ulcers and purpuric patches on the lower legs shortly following the initiation of bevacizumab. A biopsy showed an occlusive pauci-inflammatory thrombogenic vasculopathy associated with ischemic epidermal and dermal changes and accompanied by extensive vascular C5b-9 (complement C5b-9 membrane attack complex) deposition. Bevacizumab has been associated with thrombotic complications including atypical hemolytic uremic syndrome and arterial and venous thrombosis. C5b-9 may be the factor most important in the mechanism of vascular thrombosis given the extent of deposition in our index case. Thrombotic events in the skin associated with bevacizumab therapy are without precedent and dermatologists should be aware of this potential complication.

Mycobacterium fortuitum infection arising in a new tattoo

We report an uncommon case of a cutaneous infection with Mycobacterium fortuitum arising in a new tattoo. A 29-year-old man presented with a several month history of a non-pruritic papular eruption within a tattoo; the papules developed 1-to-2 weeks after the tattoo procedure. He denied similar symptoms with previous tattoos. He had been treated unsuccessfully with cephalexin. Histopathologic examination revealed perifollicular chronic and granulomatous inflammation, consistent with chronic folliculitis. Acid-fast bacilli culture identified Mycobacterium fortuitum complex. The patient was treated with a 2-month course of oral trimethoprim-sulfamethoxazole (160mg/800mg twice daily) and ciprofloxacin (250 mg twice daily), with clinical improvement at follow up after three weeks of the antibiotic regimen. Rapidly growing mycobacteria have emerged as a cause of tattoo-associated cutaneous infection in recent years. Diagnosis and treatment can be difficult without clinical suspicion. M. fortuitum and other rapidly growing mycobacteria should be considered in the differential diagnosis of tattoo-associated dermatologic complications.

Mycobacterium chelonae infection presenting as recurrent cutaneous and subcutaneous nodules – a presentation previously diagnosed as Weber Christian disease

Although the dermatologic community rarely uses “Weber-Christian Disease” as a diagnosis, it still appears in the internal medicine literature.  Herein we present a patient with recurrent cutaneous and subcutaneous nodules who was initially treated with aggressive immunosupression for a presumptive diagnosis of Weber-Christian Disease.  After more than a decade the patient was diagnosed with cutaneous Mycobacterium chelonea.  This case is an excellent example of the difficulty in diagnosing mycobacterial infections and underscores the importance of having a high suspicion for infectious etiologies for unresponsive cutaneous eruptions in patients on immunosuppressive medications.

Porokeratosis ptychotropica: a rare variant of porokeratosis

Background: Porokeratosis, a well recognized disorder of keratinization, is known to have several clinical variants. This report describes a rare variant characterized by verrucous plaques.

Methods: An adult male presented with a slowly progressive verrucous plaque on the gluteal region that was resistant to conventional therapy. Careful inspection revealed a keratotic ridge at the plaque border leading to the diagnosis.

Results: Histopathology showed the presence of multiple cornoid lamellae confirming the diagnosis of porokeratosis ptychotropica.

Conclusions: Porokeratosis ptychotropica is a rare variant of porokeratosis with fewer than 25 cases described in the literature. This report is to highlight the importance of considering this particular entity in the diagnosis of genitogluteal plaques, especially those not responding to conventional modalities.

Adult onset unilateral systematized porokeratotic eccrine ostial and dermal duct nevus: a case report

Porokeratotic eccrine ostial and dermal duct nevus (PEODDN) is an uncommon, benign dermatosis that is characterized by asymptomatic grouped keratotic papules and plaques with a linear pattern on the extremities with distinct porokeratotic histopathological features. The lesions usually appear at birth or in childhood, although rare cases of late-onset adult PEODDN have been described. Herein we report a case of adult onset PEODDN with unilateral and segmental involvement.

Recurrent paraneoplastic wells syndrome in a patient with metastatic renal cell cancer

A 58-year-old man with a history of hyperlipidemia and hypertension presented to the dermatology clinic with a 3-month history of a sudden onset, progressively worsening pruritic eruption involving the torso and extremities.  Prior treatment included azithromycin and oral and intramuscular steroids, without improvement. Laboratory results demonstrated a serum eosinophil count of 7x103/uL (normal 0-4).  A 4-mm punch biopsy of the plaque on the patient’s left thigh revealed a diffuse dermatitis with innumerable eosinophils with formation of "flame figures.” Histologically, these findings are consistent with a diagnosis of Wells syndrome (WS). A work up for possible underlying malignancy found that the patient had underlying clear cell renal carcinoma.  The eruption largely resolved following right laparoscopic nephrectomy with negative surgical margins, thus confirming the diagnosis of paraneoplastic WS. However, 2 years later the patient developed metastasis to his liver, lungs, and ribs. The patient’s cancer has continued to progress despite treatment with high-dose interleukin-2, oral sunitinib, afinitor. avastin, azacytidine, and currently axitinib. Our case is the first to describe eosinophilic cellulitis arising in a patient with underlying renal cell carcinoma.

Photo Vignette

Sclerosing perineurioma: case report and literature review

Perineuriomas are rare tumors derived from perineural cells usually presenting as a single asymptomatic papule or nodule located on an extremity of an adult. A sclerosing subtype has been rarely described. We report a case of painful sclerosing perineurioma in a 42-year-old woman.

Molluscum gladiatorum

Molluscum contagiosum is a self-limited disease that presents as small papules with central umbilication. Similar to herpes simplex virus type 1 (HSV-1) and tinea corporis, participation in wrestling is a risk factor for molluscum infection in children and adults. Referred to as herpes gladiatorum, HSV-1 causes cutaneous or ocular infections in wrestlers. We propose that molluscum contagiosum be referred to as “molluscum gladiatorum” when infection occurs in the context of wrestling. We report a case of a high school wrestler who presented with molluscum lesions on his neck.


Intractable prurigo nodularis successfully treated with combination therapy with a newly developed excimer laser and topical steroids

Prurigo nodularis (PN) is an eruption of lichenified or excoriated nodules related to intractable pruritus. A few reports have shown that a 308-nm excimer lamp/laser (EL) is effective for intractable PN. Herein, we report on two cases of intractable prurigo nodularis successfully treated with a new EL equipped with a filter to cut wavelengths shorter than 297 nm. Because this newly developed EL yields a therapeutic effect with low cumulative dosages of UV and a lower risk of DNA damage, it can be a new treatment option for intractable PN.