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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 29, Issue 3, 2023


Non-psoriatic uses of calcipotriol: a concise updated review

Calcipotriol (calcipotriene) is a synthetic vitamin D3 derivative that is a standard treatment option for psoriasis. It is generally well tolerated with minimal side effects. Due to its ability to reduce keratinocyte proliferation and induce keratinocyte differentiation as well as its immunomodulatory effects, calcipotriol has been used to treat a variety of skin disorders such as atopic dermatitis, actinic keratoses, lichen planus, seborrheic keratoses, and vitiligo [1]. We surveyed the literature examining the use of calcipotriol for non-psoriatic dermatologic disease.

Biosimilars in dermatology: identifying myths and knowledge gaps

Biosimilars are beginning to gain regulatory approval in the United States. Biosimilars are structurally near identical to the innovator and must demonstrate identical pharmacokinetics via the same binding affinity and biological function on assays. However, biologics are so complex that even the innovator company cannot produce exact duplicates; there is batch-to-batch variation. The International Psoriasis Council has outlined a biosimilarity index, which aims to standardize preclinical definitions of biosimilarity. Such an index, paired with post-approval monitoring, could provide a transparent, quantitative definition of biosimilarity. Such an index could increase trust in biosimilar medicines and the preclinical assessment process without increasing costs. As preclinical analyses are critical to biosimilar approval, manufacturers should devote proportionate resources to completing them. Dermatologists, who might reflexively look for indication-specific clinical data, might also shift their focus to preclinical variables. Finally, it should be noted that biosimilars provide more evidence of similarity than we have for different batches of the innovator product. Thus, any clinical testing standards, or lack thereof, for different batches of innovator products should also apply to biosimilars.


Workforce requirements for keratinous cysts: clinicians expend 1200 full-time effort years annually

Keratinous cysts are amongst the 10 most common dermatologic ambulatory diagnoses. Thus, we aimed to estimate the time and cost spent annually on management of keratinous cysts. We conducted a cross-sectional study using the National Ambulatory Medical Care Survey and the National Hospital Ambulatory Medical Care Survey between 2007 and 2018 (most recent years available). Conservatively, $2.1 billion per year was spent on healthcare for keratinous cysts. On average, the full-time work of 1200 (840-1800) physicians and non-physician providers are required to manage keratinous cysts yearly in the outpatient and emergency departments.We used Medicare reimbursement rates for the cost analysis which provides a conservative estimate of the total cost. Keratinous cysts impose a significant time and cost burden on the healthcare system. Treating inflamed, draining, or painful keratinous cysts or ones that occur in undesirable locations such as the face are likely of high-value due to the quality of life impact. Managing asymptomatic keratinous cysts may be of lower value. Given this burden, clinicians should continue to evaluate the value they are providing to the patient when managing keratinous cysts.

A national survey comparing practice patterns and residency training satisfaction for categorical dermatology versus combined internal medicine and dermatology trained physicians

Combined internal medicine and dermatology (med-derm) training programs were created to advance complex medical dermatology and inpatient dermatology care. A prior study demonstrated that compared to categorical dermatology residents, med-derm residents had less program satisfaction, yet indicated a stronger desire to pursue careers in academia. No follow-up data on practice patterns after training has been reported. We aimed to characterize differences in residency program satisfaction and practice patterns between physicians trained in categorical dermatology compared to med-derm residency programs. We surveyed physicians who graduated from combined med-derm programs along with their counterparts, from six institutions, that either currently or historically had a combined med-derm training, from 2008-2017. Fifty-five percent of med-derm and forty-one percent of categorical-trained physicians responded. The practice patterns between the two groups were similar. A quarter of med-derm physicians continued to provide general internal medicine services. Categorical trained physicians were significantly more satisfied with their training (P=0.03) and performed more excisions on the head/neck (P=0.02). The combined graduates had significantly greater confidence in multidisciplinary care (P=0.003), prescribed more biologic (P<0.001) and non-biologic immunosuppressive agents (P=0.002), and volunteered more for the underserved patients in their communities (P=0.04). Although few differences in overall practice patterns between categorical and med-derm trained graduates were appreciated, med-derm graduates seem more comfortable with multidisciplinary care and may care for more medically complex patients requiring immunosuppression.

Case Presentation

Diffuse skin findings secondary to lymph node tularemia in a patient with chronic rheumatoid arthritis on methotrexate

Tularemia has many atypical presentations which can represent a diagnostic challenge. The history is essential in the investigation of this disease. Bite-induced primary skin lesions should be distinguished from the infrequent immune-mediated secondary skin lesions. Herein, we present an atypical pseudovesicular rash secondary to Francisella tularensis.

Usefulness of immunohistochemical staining in diagnosing a challenging case of oral primary syphilis

Clinicians involved in the diagnosis of mucocutaneous diseases should be aware that syphilis is still prevalent among humans and its accurate diagnosis may require substantial clinical evaluation. Herein, we report a case of primary syphilis presenting as an isolated ulcer on the upper left labial oral mucosa. The lesion exhibited no specific features and could have been easily mishandled. An important clinical observation was the presence of a satellite-enlarged lymph node in the left submandibular area, which was highly indicative of primary syphilis. Histopathological examination of the specimen obtained by punch biopsy revealed features suggestive of syphilis and immunohistochemical staining with antitreponemal antibody confirmed its diagnosis with the detection of numerous Treponema pallidum in the specimen.

Cytokeratin-20 negative nodal Merkel cell carcinoma with regressed primary: a potential pitfall in interpretation of nodal metastasis

Merkel cell carcinoma (MCC) is a rare, highly aggressive cutaneous neuroendocrine carcinoma that affects sun-damaged skin. Histologically, the tumor consists of round cells with fine chromatin positive for cytokeratin 20 in ~90% of cases. Rare cases of MCC can regress spontaneously and present as nodal metastasis. Nodal MCC of unknown primary can cause a potential pitfall as they can be misinterpreted as other neuroendocrine carcinomas such as small cell carcinoma. We report a case of nodal MCC with an atypical immunohistochemistry pattern presented as bilateral axillary lymphadenopathy in a 90-year-old man with a remote history of a skin lesion that healed spontaneously leaving a scar.

Cutaneous rhabdomyoma in an 82-year-old White man

This case highlights a primary cutaneous rhabdomyoma presenting as a slowly enlarging subcutaneous nodule on the mentum of an 82-year-old White man with a medical history of two intracranial rhabdomyomas. Although they are rarely syndromic, it is important to note that the most common demographic for presentation of rhabdomyomas includes older males presenting as a subcutaneous nodule on the head, neck, or oral cavity. They are most often seen in isolation but can be multifocal in up to 25% of all cases. Being a rare entity, there is no generally recognized treatment consensus; however, complete surgical excision is recommended to prevent recurrence and morbidity from local tissue destruction.

Smokeless tobacco keratosis

Smokeless tobacco keratosis is a benign lesion characterized by the formation of white, gray, or pale macules or papules with wrinkling or rugae. It forms in the oral mucosa in response to the use of smokeless tobacco products. We present a 50-year-old man with an extensive history of smokeless tobacco use and development of the characteristic lesion. Shave biopsy showed typical changes of this benign condition and tobacco cessation was recommended.

Photo Vignette

Multiple keratotic projections on the palms and soles

Spiny keratoderma (SKD) is a rare palmoplantar keratoderma that presents with few to numerous millimetric hyperkeratotic projections on the palms and soles. It has been described with both hereditary and acquired variants. The acquired form, which presents in older adults, has been associated with a variety of systemic diseases and malignant conditions. In patients suspected of having acquired spiny keratoderma, an evaluation for malignant conditions may be warranted. Treatment with topical keratolytics or topical and oral retinoids is usually insufficient. Herein, we present the case of a 58-year-old man diagnosed with idiopathic SKD.

Localized alopecic myxedema of the scalp

Myxedema is a rare, cutaneous complication of autoimmune thyroid diseases that most often affects the anterior shins. Herein, we report a patient with a history of Graves disease and Hashimoto thyroiditis who presented with boggy, alopecic patches associated with scalp pruritus. Punch biopsies from these lesions showed increased interstitial mucin in the reticular dermis, consistent with localized myxedema. This report showcases a rare presentation of localized myxedema of the scalp, highlighting the diverse cutaneous manifestations of autoimmune thyroid diseases.

Successful radical surgical resection of a giant neurofibroma

Large neurofibromas often cause significant patient morbidity and present a unique challenge to dermatologists and surgeons. Radical resection offers the lowest rate of recurrence but is not often pursued due to the high risk of intraoperative hemorrhage and difficulty in repairing large defects. Subtotal resection and debulking are more frequently performed, leading to higher rates of recurrence. This case highlights a particularly large neurofibroma and demonstrates how surgical techniques like preoperative embolization and advancement flaps can improve outcomes in the radical resection of large neurofibromas.

Paclitaxel-induced dorsal hand-foot syndrome

Hand-foot syndrome (HFS), also known as palmoplantar erythrodysesthesia or acral erythema, is a known adverse effect of chemotherapeutic agents that most commonly presents as palmoplantar dysesthesia and erythematous plaques localized to the palms and soles. Paclitaxel is an uncommon cause of HFS and is notable for its unique presentation on the dorsal hands and feet. We present an unusual case of paclitaxel-induced HFS localized to the dorsal hands of a 66-year-old man with metastatic angiosarcoma. Early identification and management of HFS is critical to allow for continuation of chemotherapy while improving patient quality of life.


Recruitment Advertisement

Position Title: Academic Dermatologist

The University of California, Davis, School of Medicine, Department of Dermatology, is recruiting for two academic dermatologists in the Clinical X series or Health Sciences Clinical Professor (HSCP) series at the Assistant/Associate/Full Professor level based on experience and qualifications. These positions are for general medical dermatologists. Expectations of the Clinical X series are to engage in teaching, research, service, and clinical work, while expectations of the faculty in the HSCP series are primarily clinical and include teaching, service, and scholarly and/or creative activity