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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 28, Issue 6, 2022

November-December 2022


Characteristics of patients with juvenile dermatomyositis from 2001-2021 at a tertiary care center

Background: Juvenile dermatomyositis (JDM) is the most common inflammatory myopathy in the pediatric population and can represent a medical emergency. However, many features of JDM remain poorly understood, disease presentation is highly variable, and predictors of disease course have yet to be identified.

Methods: This retrospective chart review included 47 JDM patients seen at a tertiary care center over a 20-year period. Characteristics such as demographics, clinical signs and symptoms, antibody positivity, dermatopathology features, and treatments were recorded.

Results: All patients had evidence of cutaneous involvement, whereas 88.4% experienced muscle weakness. Constitutional symptoms and dysphagia were commonly present. The most frequent cutaneous findings were Gottron papules, heliotrope rash, and nailfold changes. Anti-TIF1? was the most prevalent myositis-specific autoantibody. Management involved systemic corticosteroids in nearly all cases. Strikingly, the dermatology department was only involved in the care of four in every ten (19/47) patients.

Conclusions: Prompt recognition of the strikingly reproducible skin findings present in JDM can improve disease outcomes in this population. This study highlights the need for increased education of such pathognomonic findings as well as more multidisciplinary care. In particular, a dermatologist should be involved in the care of patients presenting with muscle weakness and skin changes.


Importance of and instruction for starting a vitiligo patient support group

Starting and maintaining a vitiligo support group can appear to be a daunting task. However, with proper planning and organization, the process can become manageable and rewarding. Our guide details the reasons to start a vitiligo support group, how to start a group, how to run a group, and how to promote a group. Legal protections and details regarding retention and funding are also discussed. The authors have extensive experience leading and/or assisting support groups for vitiligo and other disease states and we also sought out other current vitiligo support leaders for their valuable insights. Previous research has found that support groups for various medical conditions may have a protective effect and membership can build resilience among participants as well as foster a sense of hope regarding their disease. Further, groups can provide a network for those living with vitiligo to connect with, uplift, and learn from one another. These groups provide the opportunity to initiate lifelong connections with those facing similar circumstances and provide members with new insight and coping strategies. Members can share perspectives with one another and empower one another. We encourage dermatologists to provide vitiligo patients with support group information and to consider being involved in, starting, or otherwise supporting them.

Case Report

Trichodysplasia spinulosa: a presentation of polyomavirus infection in immunosuppressed patients

Trichodysplasia spinulosa (TS) is a rare skin condition that occurs mainly in immunosuppressed patients. Although initially postulated to be an adverse effect of immunosuppressants, TS-associated polyomavirus (TSPyV) has since been isolated from TS lesions and is now considered to be the causative agent. Trichodysplasia spinulosa presents with folliculocentric papules with protruding keratin spines, most commonly on the central face. Trichodysplasia spinulosa can be diagnosed clinically, but the diagnosis can be confirmed with histopathological examination. Histological findings include the presence of hyperproliferating inner root sheath cells containing large eosinophilic trichohyaline granules. Polymerase chain reaction (PCR) can also be used to detect and quantify TSPyV viral load. Owing to the paucity of reports in the literature, TS is frequently misdiagnosed and there is no high-quality evidence to guide management. Herein, we present a renal transplant recipient with TS that did not respond to topical imiquimod but improved upon treatment with valganciclovir and reduction of the mycophenolate mofetil dose. Our case highlights the inverse relationship between immune status and disease progression in this condition.

Acne agminata: dermoscopic features and a short review

Acne agminata is a rare idiopathic inflammatory dermatosis. Treatment is variable with no clear consensus. We herein report a case of a 31-year-old man with sudden onset papulonodular eruptions on his face over two months. Histopathological examination revealed superficial granuloma composed of epithelioid histiocytes and scattered multinucleated giant cells, confirming acne agminata. Dermoscopy showed focal orangish structureless areas with follicular openings with white keratotic plugs. He achieved complete clinical resolution with oral prednisolone in 6 weeks. We also reviewed the literature regarding the reported treatment regimens used.

Primary cutaneous CD4+ small/medium-sized pleomorphic T-cell lymphoproliferative disorder in a young woman

Primary cutaneous CD4+ small/medium T-cell lymphoproliferative disorder (CD4+PCSM-LPD) is a low-grade cutaneous T cell disorder. There is no standardized approach to treatment of CD4+ PCSM-LPD due to its rarity. Herein, we discuss a 33-year-old woman with CD4+PCSM-LPD which resolved after a partial biopsy. We highlight that conservative and local treatment modalities should be considered prior to utilizing more aggressive and invasive treatment options.

An unexpected case of non-uremic calciphylaxis in a patient with multiple risk factors

A 58-year-old woman with a history of morbid obesity, asthma, and prior warfarin use presented to the hospital with shortness of breath and a three-month history of painful, ulcerated ulcers with retiform purpura of her bilateral distal extremities. A punch biopsy specimen demonstrated focal necrosis and hyalinization of the adipose tissue with subtle arteriolar calcium deposition, findings consistent with calciphylaxis. We discuss the presentation of non-uremic calciphylaxis and review the risk factors, pathophysiology, and interdisciplinary management approach of this rare disease.

Case Presentation

Hitchhiking spider: a case of unilateral vasculitis

A 63-year-old man presented with two days of palpable purpura over the right anterior shin and calf with notable point tenderness on the distal mid-calf without any palpable deep abnormality. Localized right calf pain worsened with walking and was associated with headache, chills, fatigue, and low-grade fevers. A punch biopsy of the anterior right lower leg showed necrotizing neutrophilic vasculitis of superficial and deep vessels. Direct immunofluorescence showed non-specific focal granular deposition of C3 within vessel walls. Three days after presentation, a live spider was found and microscopically identified as a male hobo spider. The patient suspected the spider arrived via packages shipped from Seattle, Washington. The patient was treated with a prednisone taper with full resolution of his cutaneous symptoms. Given the unilaterality of his symptoms and otherwise unexplained etiology, the patient was diagnosed with acute unilateral vasculitis secondary to hobo spider bite. Microscopic examination is required for identification of hobo spiders. Although not deadly, there have been several reports of cutaneous and systemic reactions resulting from hobo spider bites. Our case illustrates the importance of considering hobo spider bites in areas outside of their native regions, as they are known to travel in packaged items.

A crack in the armor: Wolf isotopic response manifesting as cutaneous lupus

Wolf isotopic response represents the development of skin lesions of one particular morphology occurring at the same site as another morphologically distinct and unrelated skin lesion. Cutaneous lupus erythematosus (CLE) is an autoimmune connective tissue disorder encompassing a wide range of phenotypes that may be associated with systemic involvement. Although CLE is a well-described entity with a broad spectrum, the occurrence of lesions manifesting as an isotopic response is rare. We present a patient with systemic lupus erythematosus who developed CLE in a dermatomal distribution following herpes zoster. When CLE lesions present in a dermatomal distribution, these cases may be difficult to distinguish from recurrent herpes zoster infection in an immunosuppressed patient. Therefore, they pose a diagnostic challenge and require balancing antiviral therapy with immunosuppression to sufficiently maintain adequate control of the autoimmune disease while addressing possible infections. To avoid treatment delay, clinicians should have elevated suspicion for an isotopic response when disparate lesions erupt in areas previously affected by herpes zoster or in cases of persistent eruptions at sites of prior herpes zoster. We discuss this case within the context of Wolf isotopic response and review the literature for similar cases.

Pyoderma gangrenosum associated with pseudo-Pelger-Huet anomaly in a patient with idiopathic myelofibrosis

Pseudo-Pelger-Huët anomaly is a condition in which almost all the granulocytes are hyposegmented and/or hypogranulated. It is typically recognized in peripheral blood smears and represents a marker of several disorders, such as myeloproliferative diseases and myelodysplasia. The occurrence of the pseudo-Pelger-Huët anomaly in the cutaneous infiltrate of pyoderma gangrenosum is very rare. We describe the case of a 70-year-old man with idiopathic myelofibrosis who developed pyoderma gangrenosum. Histological examination showed an infiltrate consisting of granulocytic elements with features of dysmaturity and segmentation anomalies (hypo- and hypersegmented forms), suggestive of pseudo-Pelger-Huët anomaly. Methylprednisolone treatment resulted in progressive improvement of pyoderma gangrenosum.

Bleeding complication following a shave biopsy in a patient taking ibrutinib

Ibrutinib is an oral Bruton tyrosine kinase inhibitor approved for use in patients with B-cell malignancies and has been shown to increase progression-free survival in patients with chronic lymphocytic leukemia (CLL). Ibrutinib is known to increase bleeding risk in patients with CLL. We report a patient with CLL on ibrutinib who experienced significant and prolonged bleeding after a routine superficial tangential shave biopsy for suspected squamous cell carcinoma. This prompted temporary cessation of this medication for the patient's subsequent Mohs surgery. This case demonstrates the possible severity of bleeding following routine dermatologic procedures. It is important to consider holding the medication prior to planned procedures such as dermatologic surgery.

Photo Vignette

Hemosiderotic (pigmented) atypical fibroxanthoma mimicking malignant melanoma

Atypical fibroxanthoma is a rare cutaneous malignancy that usually presents as a rapidly growing red papule on the head and neck in elderly white males. Several variants have been described. We report a patient who presented with a slowly enlarging pigmented lesion on his left ear that was clinically worrisome for malignant melanoma. Histopathologic evaluation with immunohistochemistry revealed an unusual case of hemosiderotic pigmented atypical fibroxanthoma. The tumor was successfully extirpated with Mohs micrographic surgery, with no recurrence at 6-month follow-up.

Large, linear pigmentation anomaly: an unusual dyspigmentation case

Segmental pigmentation anomalies can be further divided into segmental pigmentation disorder (SPD) complex and café-au-lait macules (CALMs). Both are congenital skin conditions characterized by hyper- or hypopigmentation. Segmental pigmentation disorder is a rare entity, whereas CALMs are common skin lesions that may be associated with various genetic conditions, especially when several are present and the patient has other indicators of a genetic abnormality. When the CALM is segmental, segmental neurofibromatosis (type V) may be considered in the differential diagnosis. Herein we present a 48-year-old woman with a history of malignant melanoma who presented with a large, linear, hyperpigmented patch on her shoulder and arm, present since around birth. The differential diagnosis consisted of CALM versus hypermelanosis (a subtype of SPD). Given a family history of a similar lesion, in addition to a personal and family history of melanoma and internal cancers, a hereditary cancer panel was completed demonstrating genetic variance of uncertain significance. This case brings attention to a rare dyspigmentation disorder and questions a possible association with melanoma.

Cerebriform eruption related to acute coral dermatitis

A 27-year-old woman presented with an acute, tender, geographic lesion on her left shin that developed after contact with a brain coral while scuba diving. Photographs obtained two hours after the incident reveal a well-demarcated, geographic, erythematous plaque with a serpiginous and cerebriform pattern at the site of contact, resembling the outermost surface contour of brain coral. The plaque resolved spontaneously over a three-week period. The biology of corals and potential biological features that lead to cutaneous eruptions are reviewed.