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Open Access Publications from the University of California

Scholarly Works (389 results)

  • Article
  • Peer Reviewed
Dermatology Online Journal, Volume 28, Issue 4 (2022)
Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare form of low-grade cutaneous lymphoma that usually presents with multifocal non-tender subcutaneous nodules over the trunk and extremities. We present an exceptional case of SPTCL masquerading as a solitary abscess which developed following an antecedent arthropod bite. Unique histological features encountered include foci of neutrophilic aggregation and admixed eosinophils within the neoplastic lymphomatous subcuticular infiltrate. As SPTCL rarely presents as an abscess, the authors wish to highlight this diagnostic pitfall and suggest excluding SPTCL as a cause of pseudo-pyoderma in patients who are afebrile with a discordant inflammatory marker profile. In addition, this condition should be suspected in non-diabetic patients who experience a rapid clinical course with suppuration and demonstrate a poor response to appropriate antibiotics. As such, we recommend sending tissue for histopathological examination for patients with atypical presentations.
    Cover page: A unique case of subcutaneous panniculitis-like T-cell lymphoma presenting as an abscess following an arthropod biteCreative Commons 'BY-NC-ND' version 4.0 license
    • Article
    • Peer Reviewed
    Clinical Practice and Cases in Emergency Medicine, Volume 2, Issue 1 (2018)
    Exaggerated arthropod bite reactions causing hemorrhagic or necrotic bullous lesions can mimic other serious conditions such as cutaneous anthrax, brown recluse spider bite, and tularemia. A 55- year-old, healthy woman presented to the emergency department with a 3.5-centimeter painless, collapsed hemorrhagic bulla at the left costal margin. She was afebrile and had no systemic symptoms. Laboratory evaluation was unremarkable. She was prescribed silver sulfadiazine cream and mupirocin ointment. The area denuded two days later and the lesion completely healed. This case illustrates the broad differential to be considered when evaluating patients with hemorrhagic bullous lesions.
      Cover page: Exaggerated Arthropod Bite: A Case Report and Review of the MimicsCreative Commons 'BY' version 4.0 license
      • Article
      • Peer Reviewed
      Mediterranean Journal of Emergency Medicine & Acute Care, Volume 2, Issue 4 (2021)

      Loxosceles genus represents a wide number of species including the brown recluse spider. This spider is known worldwide for causing serious injuries resulting from its bite. The diagnosis of brown recluse spider bite is challenging as the injury clinically resembles other conditions and cannot be confirmed unless the spider was observed. We present a case of a 46-year-old male who presented to the emergency department with sudden onset of two painful punctate lesions. We discuss the clinical presentation, investigation and approach; additionally, we briefly highlight the main points with regards to presentation, diagnosis and management of this condition.

        Cover page: A Dermatologic Condition Mimicking Brown Recluse Spider BiteCreative Commons 'BY' version 4.0 license
        • Article
        • Peer Reviewed
        UC Riverside Previously Published Works (2023)
        Histamine is a biogenic amine that regulates multiple physiological functions in diverse organisms, specifically playing a central role in the mammalian immune response. The common bed bug, Cimex lectularius L. (Hemiptera: Cimicidae), excretes histamine in large amounts in its feces as a component of its aggregation pheromone, which contaminates homes. The potential health risks associated with the presence of indoor histamine are unclear, but to predict future exposure risks, it is critical that we understand if other arthropods excrete histamine in any discernible phylogenetic pattern. In the present study, we evaluated histamine excretion by various arthropods; specifically those commonly found in large numbers indoors, other hematophagous species, and other species in the order Hemiptera. To evaluate arthropods for histamine excretion, rearing containers for each arthropod were swabbed and/or the harborage substrates were collected. Samples were then analyzed for the presence of histamine using gas chromatography-mass spectrometry. For those arthropods where histamine was present above the method detection limit, total histamine excretion was quantified over a period of 2 wk. Our results indicate that histamine excretion is limited to hematophagous hemipterans (bed bugs, bat bugs, tropical bed bugs, and kissing bugs), suggesting that indoor histamine contamination in the United States can be primarily linked to bed bugs.
          Cover page: Histamine excretion in common indoor and hematophagous arthropods.
          • Article
          • Peer Reviewed
          Dermatology Online Journal, Volume 26, Issue 3 (2020)
          Eosinophilic dermatosis of hematologic malignancy (EDHM) is a dermatosis characterized by tissue eosinophilia that has been previously reported as insect bite-like reaction. It is a rare condition with a wide variety of clinical presentations ranging from papules, nodules, or blisters that simulate arthropod bites, to the formation of plaques of differing sizes. We report a case of eosinophilic dermatosis of hematologic malignancy in a patient with a hematoproliferative disorder.
            Cover page: Eosinophilic dermatosis of hematologic malignancy: a case reportCreative Commons 'BY-NC-ND' version 4.0 license
            • Article
            • Peer Reviewed
            UC Davis Previously Published Works (2016)
            Several arthropod taxa live exclusively on vertebrate blood. This food source lacks essential metabolites required for the maintenance of metabolic homeostasis, and as such, these arthropods have formed symbioses with nutrient-supplementing microbes that facilitate their hosts hematophagous feeding ecology. Herein we highlight metabolic contributions of bacterial symbionts that reside within tsetse flies, bed bugs, lice, reduviid bugs, and ticks, with specific emphasis on B vitamin and cofactor biosynthesis. Importantly, these arthropods can transmit pathogens of medical and veterinary relevance and/or cause infestations that induce psychological and dermatological distress. Microbial metabolites, and the biochemical pathways that generate them, can serve as specific targets of novel control mechanisms aimed at disrupting the metabolism of hematophagous arthropods, thus combatting pest invasion and vector-borne pathogen transmission.
              Cover page: Grandeur Alliances: Symbiont Metabolic Integration and Obligate Arthropod Hematophagy.
              • Article
              • Peer Reviewed
              Mediterranean Journal of Emergency Medicine & Acute Care, Volume 2, Issue 4 (2021)
              Spiders are eight-legged arthropods that belong tothe arachnids class and are found on every continentexcept Antarctica.1 As of 2020, there are over 48000recognized species of spiders with more than 5000in the Mediterranean area. Out of these, only twospiders, the Latrodectus tredecimguttatus and theLoxosceles rufescens are of medical significance in theMediterranean area.1 Although most spider bites arebenign; however, severe reactions and life-threateningenvenomation do occur.
                Cover page: Brown Recluse Spider in the Mediterranean Region: A Review of the LiteratureCreative Commons 'BY' version 4.0 license
                • Article
                • Peer Reviewed
                Dermatology Online Journal, Volume 21, Issue 8 (2015)

                Erythema migrans is the initial sign in the majority of patients infected with Borrelia, the genus of spirochetes that causes Lyme disease. Early identification and treatment decrease the risk of progression to later stages of disease. Although a "bull's eye" appearance owing to lesional clearing is considered classic for erythema migrans, this feature is surprisingly often lacking among patients in the United States. Furthermore, cutaneous Lyme disease can exhibit a wide range of morphologic variability in a minority of patients. Herein, we describe the case of a patient with Lyme disease in which the presence of atypical vesicular features, in conjunction with the initial absence of clearing, resulted in multiple misdiagnoses and delayed treatment. We also review the literature on the epidemiology and management of erythema migrans for cases in which the diagnosis may pose a challenge.

                  Cover page: Vesicular erythema migrans: an atypical and easily misdiagnosed form of Lyme diseaseCreative Commons 'BY-NC-ND' version 4.0 license
                  • Article
                  • Peer Reviewed
                  Dermatology Online Journal, Volume 20, Issue 1 (2014)

                  A 50-year-old man with eosinophilic dermatosis of hematologic malignancy is presented. His dermatosis cleared after chemotherapy produced improved control of his multiple myeloma.

                    Cover page: A case of eosinophilic dermatosis of hematologic malignancy in a patient with multiple myelomaCreative Commons 'BY-NC-ND' version 4.0 license
                    • Article
                    • Peer Reviewed
                    UC San Francisco Previously Published Works (2014)

                    Background

                    Pruritic papular eruption (PPE) of HIV is common in HIV-infected populations living in the tropics. Its aetiology has been attributed to insect bite reactions and it is reported to improve with antiretroviral therapy (ART). Its presence after at least 6 months of ART has been proposed as one of several markers of treatment failure.

                    Objectives

                    To determine factors associated with PPE in HIV-infected persons receiving ART.

                    Methods

                    A case-control study nested within a 500-person cohort from a teaching hospital in Mbarara, Uganda. Forty-five cases and 90 controls were enrolled. Cases had received ART for ≥ 15 months and had an itchy papular rash for at least 1 month with microscopic correlation by skin biopsy. Each case was individually matched with two controls for age, sex and ART duration.

                    Results

                    Twenty-five of 45 cases (56%) had microscopic findings consistent with PPE. At skin examination and biopsy (study enrolment), a similar proportion of PPE cases and matched controls had plasma HIV RNA < 400 copies mL(-1) (96% vs. 85%, P = 0·31). The odds of having PPE increased fourfold with every log increase in viral load at ART initiation (P = 0·02) but not at study enrolment. CD4 counts at ART initiation and study enrolment, and CD4 gains and CD8(+) T-cell activation measured 6 and 12 months after ART commencement were not associated with PPE. Study participants who reported daily insect bites had greater odds of being cases [odds ratio (OR) 8·3, P < 0·001] or PPE cases (OR 8·6, P = 0·01).

                    Conclusions

                    Pruritic papular eruption in HIV-infected persons receiving ART for ≥ 15 months was associated with greater HIV viraemia at ART commencement, independent of CD4 count. Skin biopsies are important to distinguish between PPE and other itchy papular eruptions.
                      Cover page: Factors associated with pruritic papular eruption of human immunodeficiency virus infection in the antiretroviral therapy era
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