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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 30, Issue 2, 2024


Merkel cell carcinoma associated with TNF inhibitor therapy: a systematic review of case reports

A rare neuroendocrine skin cancer called Merkel cell carcinoma (MCC) primarily affects elderly people. The objective of this study is to comprehensively review the impact of immunosuppressive medications, particularly TNF inhibitors, on the emergence of MCC. Methods: PubMed, Web of Science, Science Direct, and Cochrane Library were searched. Study articles were screened by title and abstract at Rayyan Qatar Computing Research Institute, then a full-text assessment was implemented. Results: A total of eight case reports with 9 patients were included. Of the total population, seven were women and only two were men. Their age ranged from 31 to 73 years. More than half the population (5 cases) were being treated for rheumatoid arthritis. All received TNF inhibitors that were associated with the induction of MCC. Conclusion: We found that it is essential for physicians to explain potential cancer risks to patients before starting long-term immunosuppressive therapy and to conduct routine checks for MCC and other side effects. TNF inhibitors (infliximab, adalimumab, etanercept, and golimumab) were all associated with MCC development. Women constituted the majority of cases and most were elderly.


Improving pediatric atopic dermatitis care in the emergency department and primary care setting: a collaborative quality improvement pilot project

Emergency department visits and healthcare expenditures for pediatric atopic dermatitis have been increasing over the last two decades. There is a paucity of replicable quality improvement initiatives addressed at educating primary care and emergency medicine clinicians on this condition. The goal of this initiative was to improve clinician knowledge and comfort in the diagnosis and management of pediatric atopic dermatitis and superinfection. Clinicians were recruited via email from academic and community settings in Travis County, Texas, in 2020. They were sent a pre-intervention survey, a series of three quizzes, and a post-intervention survey. After each quiz, participants received performance feedback and various forms of multimodal education. Differences between the first and final quiz scores and clinician confidence levels were analyzed for statistical significance. Fifty-six clinicians completed the intervention. The average overall and treatment-specific scores increased significantly by 10% and 37%, respectively. Further, confidence levels improved significantly in the majority of clinicians. Clinician qualitative feedback revealed high satisfaction. Results from this educational quality improvement project have demonstrated that this is an effective and replicable resource for educating clinicians who manage pediatric atopic dermatitis in the emergency department and outpatient setting.

Case Report

Squamoid eccrine ductal carcinoma: clinical, histological and immunohistochemical features

Squamoid eccrine ductal carcinoma (SEDC) is a cutaneous adnexal malignancy that is histologically challenging to distinguish from squamous cell carcinoma. We report three cases of this rare entity and review the present literature regarding clinical, histological, and immunohistochemical features. Patients presented with a single nodule or plaque lesion on their back and temple. The shave biopsies for Patient A and C were interpreted as SEDC. Patient B's initial shave biopsy was interpreted as probable surface of squamous cell carcinoma, and subsequent excision revealed SEDC. Ductal differentiation was confirmed by positive expression of epithelial membrane antigen and carcinoembryonic antigen immunostains in all three patients. Review of the 67 previously reported cases emphasizes the importance of diagnosing SEDC accurately and promptly given its potential for distant metastasis and mortality. Perineural or lymphatic invasion is associated with higher rate of recurrence or metastasis. There should be high pathologic suspicion for SEDC in an elderly patient presenting with a palpable lesion, even if located outside of the head and neck area, particularly when there is suggestion of ductal differentiation in a sample of a squamous neoplasm.

Disseminated tuberculosis in an immunocompetent 15-year-old adolescent

Tuberculosis is one of the oldest known diseases and it remains one of the main causes of morbidity and mortality, especially in developing countries. It is associated with social inequalities and affects different age groups. Tuberculosis in children and adolescents should be considered a sentinel event, since it is linked to a recent infection through contact with bacilliferous adults. We report an immunocompetent 15-year-old adolescent with tuberculosis, exhibiting pulmonary, osteoarticular, and cutaneous involvement. Conventional treatment with tuberculostatic drugs for a year had satisfactory results without sequelae.

Case Presentation

Cutaneous mucormycosis infection owing to Rhizomucor variabilis presenting as recurrent lower limb ulceration and cellulitis in a diabetic patient

Primary cutaneous mucormycosis is caused by environmental fungi and may complicate leg ulcers or traumatic wounds even in immunocompetent individuals. This case report highlights recurrent lower limb ulcers and cellulitis in a patient with type two diabetes mellitus, which was unresponsive to conventional antibiotic treatment. Histopathology revealed the diagnosis of cutaneous mucormycosis, and fungal cultures identified Rhizopus variabilis as the causative organism. Initial courses of oral azole antifungals yielded only partial response and he eventually required more aggressive treatment with i.v. amphotericin B and oral posaconazole. Good treatment outcomes for this condition require a high index of clinical suspicion, early histopathological and microbiological diagnosis, targeted systemic antifungal therapy, and surgical debridement if necessary.

Acrokeratosis paraneoplastica (Basex syndrome) with trachyonychia preceding the diagnosis of squamous cell carcinoma of the lung

Acrokeratosis paraneoplastica (Basex syndrome) is a rare paraneoplastic condition hallmarked by psoriasiform lesion development on acral surfaces, most often related to an underlying squamous cell carcinoma. Patients may also present with nail plate changes. Successful management of this condition can be accomplished by treating the underlying malignancy.

Erythema elevatum diutinum in a patient with well-controlled Crohn disease

Erythema elevatum diutinum is a rare, chronic cutaneous leukocytoclastic vasculitis, with prominent fibrosis at its later stage. In this article, we report a case of erythema elevatum diutinum in a 23-year-old woman with well-controlled Crohn disease. To our knowledge, erythema elevatum diutinum has been reported in only three other cases of Crohn disease, in which eruptions of erythema elevatum diutinum were associated with features of active Crohn. Our patient was in clinical remission at the time of erythema elevatum diutinum onset, making this report significant not only for its uncommon presentation, but more importantly, to aid readers. diagnosis and clinical management of similar cases.

Febrile ulceronecrotic Mucha-Habermann disease - a case and treatment review

Febrile ulceronecrotic Mucha-Habermann disease is a rare and severe variant of pityriasis lichenoides, characterized by sudden onset of generalized ulceronecrotic papules that rapidly coalesce into ulcers associated with high fever. Systemic manifestations such as intravascular disseminated coagulation and pulmonary, cardiac, gastrointestinal, and central nervous system involvement are common. Treatment is based on oral corticosteroids, immunosuppressive drugs such as methotrexate, and general supportive treatment. The present case describes a stepwise approach to a patient with Mucha-Habermann disease with insufficient response to methotrexate.

Generalized Hailey-Hailey disease associated with c.2395C>T ATP2C1 gene mutation and fatal outcome.

Hailey-Hailey disease (HHD) is a rare, autosomal dominant genodermatosis caused by a mutation of the ATP2C1 gene and presenting as an erosive dermatosis, particularly in the intertriginous areas. Generalized HHD is a rare variant. We present a case of widespread, recalcitrant HHD in a middle-aged woman with a fatal outcome. No other underlying dermatosis was identified, with the possible exception of drug sensitivity to carbamazepine. Diagnosis of HHD was confirmed by histology and genetic studies which showed a c.2395C>T mutation in the ATP2C1 gene. Concurrent pemphigus was excluded. Cases of generalized HHD are extremely rare and present a challenge in diagnosis and management. Increased awareness of this severe clinical variant is needed to improve quality of care for patients with this form of HHD.

An atypical presentation of human monkeypox infection with clinicopathologic correlation

There is growing evidence to support new modes of transmission for human monkeypox infection. As these methods are being explored, this report delineates the day-to-day clinical sequelae following the initial exposure in an HIV-positive man who had sexual intercourse with another man days preceding his infection. We describe atypical cutaneous manifestations involving widespread erythematous pustules with preceding anogenital ulcerations and concomitant bilateral inguinal lymphadenopathy. Clinicopathologic correlation is used to assist in the workup and establishing the diagnosis. Our case supports others reported in the literature that suggest sexual contact as a means of transmission. More research is needed that investigates the presence of infection in both men and women, including those who could act as carriers, to elucidate other pathways in this evolving yet evasive viral disease.

Extragenital lichen sclerosus et atrophicus-morphea overlap as an initial presentation of genital lichen sclerosus

Lichen sclerosus et atrophicus (LSA) is a chronic inflammatory disorder, most often characterized by atrophic skin plaques located on female genitalia. Infrequently, LSA may present extragenitally; however, much is unknown about the temporal relationship between genital and extragenital LSA. Morphea, also known as localized scleroderma, is a rare inflammatory skin condition characterized by sclerotic plaques. Investigators debate whether LSA and morphea exist on the same spectrum of disease, with LSA representing a superficial variant of morphea involving genitalia, or if they are distinct but coincidental entities. Although researchers have described LSA and morphea occurring in different locations on the same patient, few reports describe LSA and morphea occurring in the same lesion and in the inguinal folds. Herein, we report a case of a 62-year-old woman with extragenital LSA-morphea overlap in the inguinal folds, who three months later developed genital LSA. Extragenital LSA-morphea in the same plaque, with no signs of genital lesions on initial exam, with later development of genital LSA, is especially uncommon. The temporal progression of extragenital LSA-morphea overlap to genital LSA over a three-month period is an important contribution to the literature, as the temporal relationship between extragenital and genital LSA is not previously discussed.

Localized pemphigus vulgaris on scalp: an atypical presentation.

We present two middle-aged patients with pruritic, crusted scalp erosions. Skin biopsy showed epidermal acantholysis with IgG and C3 intercellular deposits on direct immunofluorescence, leading to the diagnosis of localized pemphigus vulgaris. Resolution of the lesions without relapse occurred after low doses of oral prednisone and intralesional triamcinolone acetonide.

Drug-Induced dermatomyositis following COVID-19 vaccination

Dermatomyositis (DM) is a multi-organ idiopathic inflammatory myopathy that presents with proximal symmetric muscle weakness accompanied by characteristic cutaneous findings. Most individuals present with skin manifestations prior to muscle involvement and its course can involve the blood vessels, joints, esophagus, and lungs and can be paraneoplastic, making a malignancy assessment imperative. Although its etiology is unknown, type I interferon appears to be a component in evoking the characteristic inflammatory response and patients with DM often have an increase in type I inducible genes. Suspected triggers for DM are environmental factors, drugs, viral infections, and vaccines. The association of DM with vaccination poses a new conundrum within the medical community as people continue to get vaccinated and boosted with SARS-CoV2 vaccines, though it is worth noting that the most common challenges arose as type I hypersensitivity reactions and new onset autoimmune disorders are rare. Presented here is a 53-year-old man who was diagnosed with DM after receiving the second dose of the Pfizer vaccine. His case highlights the importance of the potential onset of autoimmune diseases following the COVID-19 vaccine, a phenomenon that clinicians should be aware of as the discourse concerning the pandemic continues.

A case of melanoma in situ of the central forehead repair by V-Y advancement flap and Burow graft

Large defects on the face after Mohs surgery have posed significant reconstructive challenges. A 90-year-old man presented with melanoma in situ of the central forehead, which resulted in a 4.5cmx4.3cm defect after multiple stages of Mohs surgery. Although different approaches for forehead repair with nasal root involvement are possible, we demonstrate that the V-Y advancement flap and subsequent Burrow graft for nasal root repair represents a viable closure technique for large circular defects of the central forehead.

The rope sign, a typical and yet infrequent clue

Cutaneous granulomatous reactions are diverse, both from the clinical and the pathological perspective. Most underlying pathophysiological aspects remain elusive. Interstitial granulomatous dermatitis and palisaded neutrophilic and granulomatous dermatitis have been claimed to be reactions to systemic disorders, such as infectious, inflammatory, or neoplastic conditions. Recently, the overarching term "reactive granulomatous dermatitis" has been coined to unify both entities. We herein report two cases of reactive granulomatous dermatitis presenting with the widely known, albeit infrequent "rope sign" and provide clinicopathological correlation. The two patients included a 53-year-old woman with enlarging erythematous plaques and underlying palpable cords on both sides of trunk near axillae (rope sign), and a 51-year-old woman with personal history of rheumatoid arthritis and a palpable cord on the left aspect of the trunk. Pathological findings were compatible with reactive granulomatous dermatitis in both cases. In conclusion, the rope sign represents a strikingly infrequent but decisive diagnostic clue of reactive granulomatous dermatitis.

Angiosarcoma: hiding in plain sight

Angiosarcoma is a rare, aggressive soft-tissue sarcoma of endothelial origin that necessitates early recognition, diagnosis, and treatment. The most commonly reported presentation consists of violaceous patches and plaques on the head and neck of elderly white men, with fewer reports affecting patients with Skin of Color. Most cases of angiosarcoma are idiopathic and tend to recur locally with early metastasis, conferring a poor prognosis. We report a case of an 83-year-old Fitzpatrick skin type IV man who presented with a large violaceous-to-black mamillated plaque on the frontotemporal scalp that was clinically highly suggestive of cutaneous angiosarcoma. However, unrevealing histopathology complicated our diagnostic process and delayed management. Immunohistochemistry was invaluable in determining the diagnosis of angiosarcoma. Our case highlights the aggressive nature of cutaneous angiosarcoma, necessitating close clinicopathologic correlation to confirm the diagnosis and initiate treatment.

Refractory chronic spontaneous urticaria after heterologous COVID-19 booster vaccination

Chronic spontaneous urticaria (CSU) involves recurrent, pruritic wheals lasting more than 6 weeks in response to various etiologies, including unknown causality. Though most cutaneous reactions to the COVID-19 vaccine series are self-limited and of short duration, more complex presentations including chronic spontaneous urticaria have been described. To the best of our knowledge, this is the first report of chronic spontaneous urticaria following heterologous mRNA COVID-19 booster vaccination that includes vaccination with both forms of the mRNA vaccine. Our patient received Pfizer-BioNTech for the primary series and Moderna for the booster. After failing several therapies, our patient's urticaria was refractory even to omalizumab. The source for chronic spontaneous urticaria development in our patient may be related to the unique humoral response elicited by receipt of a different mRNA vaccine manufacturer.

Porokeratosis on the lip: A Case Series

Porokeratosis is a skin condition that involves the formation of plaques, characterized by a hyperkeratotic ridge with an atrophic center. There is a histological presence of a cornoid lamella, which is a parakeratotic column that traverses through the stratum corneum. The plaques are mostly benign but have the potential to become squamous cell carcinomas if left untreated. Porokeratosis lesions typically occur on the extremities, but they can develop anywhere. The occurrence of porokeratosis on the lip is exceedingly rare. We report three cases of porokeratosis on the lip. Each incidence was treated with cryotherapy, which was unsuccessful in two. One of these two patients did not elect for topical treatment and is being monitored for lesion changes. The second patient was successfully treated via shave biopsy. The third patient was lost to follow-up post-cryotherapy.

Photo Vignette

A rare case of meloxicam-induced pseudoporphyria

Drug-induced pseudoporphyria is commonly linked to nonsteroidal anti-inflammatory drugs (NSAIDs) such as naproxen, oxaprozin, ketoprofen, and ibuprofen. The NSAID meloxicam is not a commonly reported inciting agent. We report a case of meloxicam-induced pseudoporphyria in a 55-year-old woman with a past medical history of hypertension, hyperlipidemia, gastroesophageal reflux disease, and osteoarthritis. She presented to the clinic with tense and denuded bullae on her dorsal feet, which was diagnosed as pseudoporphyria after further workup. Upon evaluating the patient's medication history, meloxicam was identified as the most likely inciting agent. The patient's condition resolved with the discontinuation of this medication. Our findings can help dermatologists effectively diagnose and treat meloxicam-induced pseudoporphyria in patients with similar cases.

Nodular hidradenoma: clinical, dermoscopic, and histopathological features

Nodular hidradenoma is an infrequent benign tumor originating from the proximal portion of the sweat glands, most commonly associated with the apocrine glands. Owing to its variable clinical presentation, correctly diagnosing nodular hidradenoma can be challenging, with several potential conditions in the differential diagnosis to consider. This article presents a healthy 52-year-old woman with an atypical location of nodular hidradenoma, highlighting the critical role of integrating clinical, dermoscopic, and histopathological characteristics for an accurate diagnosis. We discuss the clinical features, dermoscopic findings, histological examination, differential diagnosis, and treatment options for nodular hidradenoma, emphasizing the importance of surgical intervention in preventing potential malignant transformation.


Corrigendum: Spindle cell lipoma: a rare case report on the hallux

The original article was published on February 15, 2024 and corrected on April 15, 2024.The revised version of the article corrects Figure 2. The changes appear in the revised online PDF copy of this article.