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Open Access Publications from the University of California

Scholarly Works (314 results)

  • Article
  • Peer Reviewed
Dermatology Online Journal, Volume 23, Issue 9 (2017)

A 61-year-old immunosuppressed renal transplant patient with inflammatory bowel disease presented with tender pink nodules on the trunk and extremities. An initial biopsy was suggestive of metastatic Crohn disease, but after disease persistence, a second biopsy revealed disseminated Mycobacterium haemophilum. Atypical mycobacterial infections should be considered in immunosuppressed patients. This case highlights the complexities of diagnosing such infections in patients with an underlying granulomatous condition and the particular growth requirements of M. haemophilum.

    Cover page: Mycobacterium haemophilum infection in a renal transplant patient with inflammatory bowel diseaseCreative Commons 'BY-NC-ND' version 4.0 license
    • Article
    • Peer Reviewed
    Dermatology Online Journal, Volume 26, Issue 9 (2020)
    Cutaneous non-tuberculous mycobacterial (NTM) infections have rapidly increased in incidence in recent years. Currently there is no standard treatment and the variable and nonspecific ways in which cutaneous NTM infection presents makes it a therapeutic and diagnostic challenge. We describe a 67-year-old immunocompetent woman with cutaneous NTM infection after she recently underwent a root canal procedure. Although the species was not identified and she was unable to tolerate multiple antibiotics, she ultimately responded well to three months of treatment with linezolid. Given that cutaneous NTM infection can present in immunocompetent patients and that the incidence is rising, it is important for clinicians to maintain a high index of clinical suspicion, especially in patients with a recent history of surgery, trauma, or cosmetic procedures. Linezolid has coverage against non-tuberculous mycobacteria and is an effective therapeutic option for cutaneous NTM cases in which identification to the species level is not possible or when adverse effects limit therapeutic options.
      Cover page: Linezolid as a treatment option for cutaneous non-tuberculous mycobacterial infectionsCreative Commons 'BY-NC-ND' version 4.0 license
      • Article
      • Peer Reviewed
      Dermatology Online Journal, Volume 27, Issue 6 (2021)
      Nontuberculous mycobacteria are pathogens with diverse manifestations in immunocompromised hosts. The lesser-known Mycobacterium haemophilum usually causes cutaneous infection. Diagnosis is challenging but is aided by molecular testing and multidisciplinary communication. We present an immunocompromised patient with disseminated cutaneous mycobacterial infection with digital tenosynovitis.
        Cover page: Disseminated atypical mycobacterial infection in an allogeneic stem cell transplant recipientCreative Commons 'BY-NC-ND' version 4.0 license
        • Peer Reviewed
        UC Irvine Previously Published Works (1994)
        Mycobacteria have been known since the nineteenth century to be pathogenic for humans. Thus Koch first described the tubercle bacillus in 1882. Before the turn of the century, atypical variants had also been appreciated that were associated with disease in animals. Over time a greater appreciation of these organisms and their means of spread led to better attempts at control and treatment of these agents. With the introduction into society of the human immune deficiency virus (HIV), however, the natural mechanisms by which the body controls the organisms were significantly impaired in HIV-infected patients and atypical forms of mycobacterial disease became prevalent. These organisms have now become one of the most significant threats to these individuals and on occasion may require some form of surgical intervention.
          Cover page: Mycobacterial Disease in the AIDS PatientCreative Commons 'BY' version 4.0 license
          • Article
          • Peer Reviewed
          UC Davis Previously Published Works (2021)

          Background

          Mycobacterial infections in cats are challenging to treat and incompletely described.

          Hypothesis/objectives

          To describe the features of mycobacterial infections in cats from northern California.

          Animals

          Nineteen cats, all with nontuberculous mycobacterial (NTM) infections; 4 with Mycobacterium avium infection, 15 with rapid-growing mycobacterial (RGM) infection.

          Methods

          Retrospective study. Cases with positive mycobacterial culture, species identification, and susceptibility testing were included. Descriptive statistics were used. Fisher's exact test and Mann-Whitney U test were used for comparisons between M avium and RGM infections (P ≤ .05).

          Results

          Rapid-growing mycobacterial cases included Mycobacterium smegmatis (9), Mycobacterium fortuitum (4), Mycobacterium abscessus (1), and Mycobacterium thermoresistibile (1). Mycobacterium avium infections were more likely than RGM infections to be disseminated (3/4 vs 0/15; P = .004). Disease of the skin/subcutis (15/15 vs 0/4; P < .001) and outdoor access (14/15 vs 0/4; P = .001) were primary features of RGM infections. Resistance to fluoroquinolones and aminoglycosides was common among M avium isolates. A high prevalence of resistance to third- and fourth-generation cephalosporins was noted in RGM species. Death/euthanasia was noted only in M avium cases (3/4). Twelve of 15 cats with RGM infection had available follow-up; 4 of these cats achieved remission.

          Conclusions and clinical importance

          The most prevalent RGM species isolated from cats from northern California are M smegmatis and M fortuitum. Susceptibility to prescribed antimicrobials does not appear to guarantee treatment success. Combination drug treatment is recommended. Repeat culture and susceptibility testing should be performed when disease is persistent/relapsing.
            Cover page: Feline mycobacterial disease in northern California: Epidemiology, clinical features, and antimicrobial susceptibility.Creative Commons 'BY-NC' version 4.0 license
            • Article
            • Peer Reviewed
            Dermatology Online Journal, Volume 19, Issue 8 (2013)

            Atypical mycobacterial infections are more commonly described among immunocompromised patients, although there has been an increasing incidence in recent years of infections in immunocompetent hosts. Normally preceding trauma is a risk factor for infection. We describe a case of Mycobacteria chelonae infection in a healthy individual with no risk factors.

              Cover page: Mycobacteria infection in an immunocompetent patient with no risk factors: evaluation and management of non-healing majocchi granuloma-type noduleCreative Commons 'BY-NC-ND' version 4.0 license
              • Article
              • Peer Reviewed
              Dermatology Online Journal, Volume 23, Issue 8 (2017)

              We report a patient with psoriasis who developed Mycobacterium marinum (M. marinum) infection after seven years of treatment with adalimumab, a human anti-TNF (tumor necrosis factor) monoclonal antibody. TNF is a pro-inflammatory cytokine that plays a central role in the pathogenesis of psoriasis and a number of other immune-mediated inflammatory diseases. TNF plays an important role in granuloma formation and host defense against mycobacterial infections. Several cases of atypical mycobacterial infections in patients on TNF inhibitors have been reported. To our knowledge, this is the second reported case of M. marinum infection in a patient on adalimumab for the treatment of psoriasis.

                Cover page: Mycobacterium marinum infection contracted from seaweed wrap in a psoriasis patient undergoing treatment with adalimumabCreative Commons 'BY-NC-ND' version 4.0 license
                • Article
                • Peer Reviewed
                UC San Francisco Previously Published Works (2024)
                Imaging evaluation for lower extremity infections can be complicated, especially in the setting of underlying conditions and with atypical infections. Predisposing conditions are discussed, including diabetes mellitus, peripheral arterial disease, neuropathic arthropathy, and intravenous drug abuse, as well as differentiating features of infectious versus non-infectious disease. Atypical infections such as viral, mycobacterial, fungal, and parasitic infections and their imaging features are also reviewed. Potential mimics of lower extremity infection including chronic nonbacterial osteomyelitis, foreign body granuloma, gout, inflammatory arthropathies, lymphedema, and Morel-Lavallée lesions, and their differentiating features are also explored.
                  Creative Commons 'BY' version 4.0 license
                  • Article
                  • Peer Reviewed
                  Dermatology Online Journal, Volume 25, Issue 2 (2019)
                  Mycobacterium marinum is a nontuberculous mycobacteria with worldwide distribution that lives in fresh or salt water and is responsible for infections in fish, and sometimes in humans. Human disease consists mainly of cutaneous nodules, but deep structure involvement may also occur. Diagnosis of M. marinum infection remains a challenge, with a considerable time delay between onset of symptoms and diagnosis. We present a 33-year-old man with no immunosuppressive history who was seen in our department with skin nodules over his hand and forearm, distributed in a sporotrichoid pattern. His hobbies included maintaining an aquarium of tropical fish. Histological examination of the patient's skin biopsy was compatible with the diagnosis of mycobacterial infection, and the Ziehl-Neelsen staining revealed acid-fast bacilli. Molecular techniques confirmed the suspicion of M. marinum infection. A necropsy was performed on one of the patient's fish, more specifically, a Poecilia reticulata, and resulted in identification of M. marinum from its gut. The patient was treated with clarithromycin, ethambutol, and rifampicin for 9 months, with clearance of infection.
                    Cover page: Mycobacterium marinum lymphocutaneous infectionCreative Commons 'BY-NC-ND' version 4.0 license
                    • Article
                    Dermatology Online Journal, Volume 23, Issue 9 (2017)

                    Actinic keratoses are cutaneous lesions that appear as the result of the proliferation of atypical keratinocytes. These lesions are considered pre-malignant and they can progress to squamous cell carcinoma. Ingenol mebutate has been approved as an effective treatment for AK on the face and trunk. We studied the local skin reactions to this therapy. Data about local skin reactions were collected in a series of 5 patients with photographic documentation, a visual analog scale, and a ranking of satisfaction of the patient. Moderate to severe reactions were reported in most of patients, but only one stopped treatment early. The short duration of treatment contributes to high adherence to the therapy.

                      Cover page: Mycobacterium fortuitum infection after acupuncture treatmentCreative Commons 'BY-NC-ND' version 4.0 license
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