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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 25, Issue 9, 2019


Review of onychocryptosis: epidemiology, pathogenesis, risk factors, diagnosis and treatment

Ingrown toenail, or onychocryptosis, is a highly prevalent nail condition that occurs when the nail edge grows into the periungual dermis. It most frequently affects the hallux and has a biphasic presentation, being most common in the second and fifth decades. It is often painful and may be debilitating in severe cases. Risk factors include trauma, weight changes, poor nail-cutting technique, and hyperhidrosis. Both conservative and surgical treatments have been described, and choice of therapy is dependent on patient co-morbidities, severity, and associated symptoms. This review covers the epidemiology, risks factors, pathogenesis, evaluation, and staging of ingrown toenails, as well as, treatment options. Although there is an unmet need for clinical trials comparing therapies, current recommendations are to treat conservatively and then proceed to surgical therapies if symptoms persist.

Omphaloliths: a case series and review of 29 cases in literature

Omphaloliths are uncommon benign umbilical lesions caused by the accumulation of sebum and keratin into a stone-like concretion. Recognition of this entity can prevent unnecessary procedures and imaging studies for uncomplicated cases. We present three cases of omphaloliths from our department and review all 26 cases previously reported in the English literature with regard to modes of presentation, potential risk factors, complications, and treatment options to guide clinicians. The mean age at presentation was 48 years. Of the 29 cases, 17 (59%) were asymptomatic. Male patients presented at a younger age and were more likely to present with complications compared to females who presented at an older age with asymptomatic lesions (P=0.006). Features of patients described included dementia, hirsutism, a deep or narrow umbilicus, multiple nevi, obesity, and poor hygiene. Two patients developed overlying pyogenic granulomas. Removal of asymptomatic lesions was uncomplicated and done using forceps or following irrigation, with no recurrence. Complications, including localized abscesses and peritonitis, were associated in 41% of patients who were treated surgically; recurrence was noted in one patient. Removal of omphaloliths is recommended, once identified, to reduce risks of complications and patients should be encouraged to improve their personal hygiene.


What patients see online: assessing the online identities of Pennsylvania dermatologists

Introduction: Patients use the internet to search for health-related information. We sought to characterize the information that patients find when searching for dermatologists on Google. Methods: The Centers for Medicare and Medicaid Services (CMS) Physician Comparable Downloadable File was utilized to identify all Medicare-participating dermatologists practicing in Pennsylvania (PA). A custom Google-based search engine was used to search each dermatologist. Up to the top 10 results for each physician were then sorted into: (1) physician, hospital, or healthcare system, (2) third-party, (3) social media, (4) academic journal articles, or (5) other. Results: Within the CMS, 519 health care providers (53.9% male, 46.1% female) self-identified as dermatologists practicing in PA. At least one search result was obtained for each physician (4,963 total search results). About 30.6% (1,519) search results were hospital, health system, or physician-controlled websites, and 26.6% (1,318) were third-party websites (1,318; 26.6%). Social media websites accounted for 601 (12.1%) hits whereas peer-reviewed academic journal websites generated 135 (2.7%) results. One-way chi-square analysis showed domains were not randomly distributed across the five categories (P<0.0001). Conclusion: Dermatologists should be better aware of their digital presence and the strategies to better control their online identity.

Interactive teaching and repeat exposure maximize medical student satisfaction but do not promote long-term retention of dermatologic knowledge

Background: Instructional methods for teaching medical students to recognize common skin lesions vary widely. There is little published data comparing various teaching methods and their impact on medical student retention of dermatologic knowledge. Methods: Our prospective cohort study analyzed how teaching methods (interactive teaching versus. traditional didactic teaching versus. self-guided review alone) impacted second year medical students' ability to recognize common skin lesions one year after initial exposure to the material. Our study also looked at student satisfaction with different teaching methods. Results: There was no significant difference in long-term retention of knowledge between different teaching methods. However, students preferred the interactive format over the traditional didactic format. Spaced review is important for long-term retention, but an in-class review session two months after content was initially taught provided no added benefit over spaced self-review alone. Conclusions: Medical students are able to maintain long-term retention of dermatologic knowledge irrespective of in-class teaching method. Repeat exposure to material is important but self-review of dermatology alone is sufficient for long-term retention. Dermatology course directors should incorporate interactive teaching into medical school curricula to increase learner satisfaction.

Case Report

Primary cutaneous Epstein-Barr virus-positive diffuse large B-cell lymphoma (DLBCL) in a patient taking fingolimod

A 55-year-old man with relapsing-remitting multiple sclerosis on fingolimod presented to the dermatology clinic with skin lesions on the left temple and cheek. Histopathology showed a diffuse infiltrate of enlarged, atypical lymphocytes throughout the dermis with an overlying grenz zone and a subpopulation of scattered smaller lymphocytes and plasma cells. Epstein-Barr virus-encoded RNA in situ hybridization stain was positive. Based on the morphologic and immunophenotypic findings, a diagnosis of EBV-positive diffuse large B-cell lymphoma was made. This case aims to raise awareness for the dermatologist that patients on fingolimod may be at increased risk of lymphoproliferative disorders.

Case Presentation

Nutritional deficiency dermatitis related to branched-chain amino acid restriction in a child with maple syrup urine disease

We present a one-year-old girl with maple syrup urine disease with dermatitis secondary to the restriction of amino acids as part of the treatment. We present the clinical evolution and histopathological correlation.

Vulvar Majocchi granuloma and kerion formation in an immunocompetent female

We report a rare case of vulvar Majocchi granuloma and kerion formation secondary to Trichophyton in an immunocompetent woman. The patient responded well to oral terbinafine and a short course of oral corticosteroids with a slow taper. Resolution of deep dermatophytosis requires prompt pathogen identification and treatment to avoid scarring and hair loss. Herein, we aim to increase clinical awareness and early recognition of this atypical presentation of a Majocchi granuloma with kerion formation.

Photo Vignette

Two cases of atypical periorificial dermatitis caused by Candida parapsilosis in patients volunteering in dog shelters

Candida is a genus of yeasts that can be a part of normal human skin flora, but may cause disease when the skin barrier is compromised. C. albicans is the most common pathogenic species of this genus, but in recent years infection with other species, such as C. parapsilosis has been growing. C. parapsilosis is a species of Candida that has been found in the skin of humans and other mammals, including dogs. In this brief report, the authors describe two cases of atypical periorifical infection with C. parapsilosis in patients who both volunteered in dog shelters. Owing to the atypical presentation of the fungal infections, the isolation of C. parapsilosis as the causative organism and their extensive history of exposure to dogs, these cases may represent the first evidence of possible zoonotic transmission of C. parapsilosis from dogs to humans.

Tufted angioma presenting with subclinical coagulopathy

Tufted angioma is a rare, benign vascular tumor of uncertain pathogenesis, characterized histopathologically by "tufts" of capillaries within the dermis. A life-threatening coagulopathy, Kasabach-Merritt phenomenon, occurs in approximately 10% of cases of tufted angioma and is characterized by profound thrombocytopenia and fibrinogen consumption. We present an asymptomatic 10-month-old boy who presented with an erythematous patch of the right upper extremity and subsequently was diagnosed by biopsy with tufted angioma. Baseline laboratory workup of our patient revealed mildly decreased fibrinogen and elevated D-dimer levels without thrombocytopenia or elevated partial thromboplastin time. This suggests that asymptomatic patients with tufted angioma may present with coagulopathy in the absence of Kasabach-Merritt phenomenon. This also highlights the importance of obtaining baseline laboratory workup in patients presenting with tufted angioma.

Digital ulcerative lichenoid dermatitis in a patient receiving anti-PD-1 therapy

Programmed cell death receptor 1 inhibitors (anti-PD-1) constitute a form of immunotherapy for the treatment of several cancers. They are associated with cutaneous immune-related adverse events (irAE), occurring in up to 50% of patients. Lichenoid dermatitis is frequent and several presentations have been described. Although attempts have been made to study these reactions, they are yet to be fully characterized and the relationship with tumor response is unclear. We describe a case of digital ulcerative lichenoid dermatitis resembling ulcerative cutaneous lichen planus that occurred during pembrolizumab therapy for oral squamous cell carcinoma. The patient developed a painful ulcer on his index finger 18 months into therapy. Biopsy revealed epidermal ulceration with intense lichenoid dermatitis. Immunohistochemical study revealed intense CD8 positivity at the ulcer's edges and marked CD163 positivity at its base. Although idiopathic forms of this type of lichenoid dermatitis are particularly recalcitrant, our case was successfully managed with topical therapy and oncologic treatment did not require modification. One year after ending treatment the patient remains free of disease progression. It is unclear if this reaction is associated with his favorable oncologic response. This report adds an undescribed reaction to the increasing diversity of cutaneous irAE associated with anti-PD-1 therapy.

Pigmented fungiform papillae of the tongue: a clinical and histologic description

A 28-year-old man with a history of mycosis fungoides presented for evaluation of multiple dark-brown macules and hyperpigmented dome-shaped papules on the distal tongue. A shave biopsy of the tongue revealed melanin pigment in the basal keratinocytes and melanophages in the lamina propria, consistent with pigmented fungiform papillae of the tongue. Relevant clinical and histologic features of this diagnosis are reviewed.

Classic features of primary systemic amyloidosis (AL amyloidosis) leading to diagnosis of plasma cell myeloma

The diagnosis of primary systemic amyloidosis, also known as AL (amyloid light-chain) amyloidosis, is often delayed owing to its nonspecific manifestations as well as its rarity. A 64-year-old woman presented with an eight-month history of significant weight loss, anemia, fatigue, and progressive painful cutaneous lesions on her hands, lips, back, perianal, and vulvar area that were originally treated unsuccessfully with antimalarials and systemic corticosteroids. Histopathological examination revealed an amorphous dermis with pale pink material that demonstrated positive birefringence with Congo red staining. Subsequently, the patient underwent a bone marrow biopsy, which uncovered a plasma cell myeloma, the source of her amyloidogenic protein production.


Systemic contact dermatitis related to alcoholic beverage consumption

Systemic contact dermatitis is a rash secondary to systemic exposure to allergens after sensitization. Numerous agents are implicated including Balsam of Peru, a plant-derived compound often used for flavoring and fragrance. Alcoholic beverages can contain many possible allergens, including cinnamon, vanilla, citrus peels, and Balsam of Peru. Herein, we describe two patients presenting with recurrent, diffuse, erythematous, and pruritic cutaneous eruptions suspicious for contact dermatitis. Based on clinical history, exam, and formal and at-home patch testing results, we believe the most likely etiology was Balsam of Peru within the alcohol beverages leading to systemic contact dermatitis. Both patients markedly improved after avoidance of their alcoholic beverages. Overall, systemic contact dermatitis secondary to alcohol consumption is a rare phenomenon, whereas Balsam of Peru is a relatively common allergen. Suspicion must be high to identify possible allergens (including Balsam of Peru) exposure within alcoholic beverages such as artificial flavorings, aromas, and mixtures.

Successful treatment of hidradenitis suppurativa in the setting of Crohn disease with combination adalimumab and ustekinumab

Herein we report the combination of adalimumab and ustekinumab to successfully treat a 39-year-old woman who presented for evaluation of hidradenitis suppurativa in the setting of Crohn disease of both the small and large intestine. The patient reported previous control of her hidradenitis when she was using adalimumab for her Crohn disease. She had recently been started on ustekinumab for Crohn disease and had flaring of her hidradenitis. The patient re-started on adalimumab weekly and ustekinumab every 8 weeks. After one month, the patient reported clear improvement in her hidradenitis and Crohn disease with the combined therapy.

Contact dermatitis: one for the books

Allergic contact dermatitis (ACD) is a frequent problem, often caused from repeated exposure to an object or substance related to the patient's routine activities. We present a case of a well-demarcated, erythematous, scaly plaque on a finger caused from reading with an e-book device. Although metal from mobile devices can cause ACD, mobile device cases may cause irritation or contain additives that can also cause contact dermatitis. Similar presentations of contact dermatitis may become more common as technology use increases.