Unilateral Blastomyces dermatitidis endophthalmitis and orbital cellulitis. A case report and literature review

Practical Guidance for Clinical Microbiology Laboratories: Diagnosis of Ocular Infections

The variety and complexity of ocular infections have increased significantly in the last decade since the publication of Cumitech 13B, Laboratory Diagnosis of Ocular Infections (L. D. Gray, P. H. Gilligan, and W. C. Fowler, Cumitech 13B, Laboratory Diagnosis of Ocular Infections, 2010). The purpose of this practical guidance document is to review, for individuals working in clinical microbiology laboratories, current tools used in the laboratory diagnosis of ocular infections. This document begins by describing the complex, delicate anatomy of the eye, which often leads to limitations in specimen quantity, requiring a close working bond between laboratorians and ophthalmologists to ensure high-quality diagnostic care. Descriptions are provided of common ocular infections in developed nations and neglected ocular infections seen in developing nations. Subsequently, preanalytic, analytic, and postanalytic aspects of laboratory diagnosis and antimicrobial susceptibility testing are explored in depth.

Antimicrobial guide to posterior segment infections

PURPOSE

This review article is meant to serve as a reference guide and to assist the treating physician in making an appropriate selection and duration of an antimicrobial agent.

METHODS

Literature review.

RESULTS

Infections of the posterior segment require prompt medical or surgical therapy to reduce the risk of permanent vision loss. While numerous options exist to treat these infections, doses and alternative therapies, especially with contraindications for first-line therapy, are often elusive. Antimicrobial agents to treat posterior segment infections can be administered via various routes, including topical, intravitreal, intravenous, and oral.

CONCLUSIONS

Although there are many excellent review articles on the management of endophthalmitis, we take the opportunity in this review to comprehensively summarize the appropriate antimicrobial regimen of both common and rare infectious etiologies of the posterior segment, using evidence from clinical trials and large case series.

Blastomyces species and orbital apex syndrome: Unsuspected co-infection

Blastomyces species are thermally dimorphic fungi existing as yeast in tissue. We report an initially immunocompetent patient with orbital apex syndrome (OAS) whose presentation suggested giant cell arteritis. Subsequently, metastatic carcinoma was entertained as a cause of OAS until bronchoscopy yielded Blastomyces species. The patient rapidly succumbed with multiorgan failure despite Amphotericin B administration. At post-mortem, Blastomyces co-infection with fungal hyphae in keeping with Aspergillus species was found in cavernous sinus and in infarcted optic nerve. To the best of our knowledge, co-infection with these two organisms in this clinical setting has not been reported.

Blastomycosis of the head and neck

BACKGROUND

Blastomyces dermatitidis infection of head and neck structures is a rare clinical entity. However, the potential for significant morbidity warrants clinical consideration and timely diagnosis.

OBJECTIVE OF REVIEW

To describe the clinical presentations, diagnostic challenges, and outcomes of otolaryngologic blastomycosis.

SEARCH STRATEGY

A literature search of the Pubmed and Ovid databases with the terms "blastomycosis AND. . . " followed by all terms related to anatomical regions of the head and neck.

EVALUATION METHOD

All publications which discussed pertinent otolaryngologic involvement from blastomycotic infections were evaluated.

RESULTS AND CONCLUSION

The larynx was the most commonly reported site of infection, followed by the oral cavity, neck, ear, nasal cavity/paranasal sinuses, and skull base/orbit/calvarium. Diagnosis of blastomycosis was almost universally delayed due to the resemblance of presentation to more common clinical entities, most notably squamous cell carcinoma. A substantial portion of cases (42%) presented without clinical or radiographic evidence of pulmonary infection. The initial diagnostic confusion often resulted in disease progression and trials of invasive therapies. Most patients experienced complete resolution of symptoms and lesions within months of initiation of proper antifungal medications. Permanent sequelae were relatively uncommon and related to the structures involved in the primary infection.

Etiological agents of fungal endophthalmitis: diagnosis and management

Endophthalmitis caused by fungi is commonly diagnosed around the world in apparently healthy and immunocompromised individuals. An accurate clinical diagnosis for endophthalmitis confirmed by laboratory techniques is essential for early treatment with antifungal drugs, such as amphotericin B, imidazoles, and other antifungals. Here, we review endophthalmitis caused by fungi according to its classification into endogenous fungal endophthalmitis (EFE) and exogenous fungal endophthalmitis (EXFE). EFE is caused by endogenously acquired fungi, whereas the traumatic implantation of opportunistic fungal pathogens is the main feature of EXFE. We highlight the most important etiologies causing endophthalmitis and the steps required for a rapid diagnosis and management.

Orbital cellulitis and endophthalmitis in pseudomonas septicemia

We report a case of concurrent orbital cellulitis and endophthalmitis that resulted from endogenous complications of community-acquired Pseudomonas aeruginosa bacteremia in an apparently healthy individual. Pseudomonas pneumonia and extensive focal skin lesions of ecthyma gangrenosum also complicated the condition. The presence of drug-induced neutropenia was a risk factor in this patient. Simultaneous orbital cellulitis and endophthalmitis developed and rapidly progressed. Intravenous, intravitreal, and topical antibiotics were administered along with frequent eye wash with normal saline to dilute copious purulent discharge from a deep subcutaneous abscess of lower eyelid. Because of the exocellular products of Pseudomonas aeruginosa, the sclera and corneal stroma were degraded, resulting in nearly perforated cornea. Tarsoconjunctival flap from the upper eyelid was performed to reconstruct the thinning areas. After the infection was controlled, the patient's ultimate visual acuity was light perception.

Unilateral Blastomyces dermatitidis optic neuropathy case report and systematic literature review

OBJECTIVE

To describe the clinical and histopathologic findings of a unique case of isolated optic nerve Blastomyces dermatitidis infection and to summarize the ophthalmic blastomycosis literature.

DESIGN

Case report and systematic literature review.

METHODS

A 70-year-old healthy man experienced impaired vision in his left eye. Magnetic resonance imaging (MRI) showed an enhancing process of the left optic nerve sheath. Although vision initially improved with oral dexamethasone, visual acuity subsequently decreased from 20/25 to no light perception over 8 weeks. An optic nerve biopsy revealed blastomycosis. Because ophthalmic blastomycosis infections are unusual, the Cochrane Library, PubMed, OVID, and UpToDate databases were searched using the term blastomycosis with the limits English and humans. Articles that predated the databases were gathered from current references.

MAIN OUTCOME MEASURES

Visual acuity of the left eye and MRI of the orbits and brain.

RESULTS

Histopathologic examination of the nerve specimen showed B. dermatitidis infection. Needle biopsy and culture results of a suspicious lung scar were positive for Blastomyces. The patient was treated with intravenous amphotericin B followed by oral itraconazole for 6 months. The left eye remained blind 23 months after the biopsy. Approximately 40 articles describing ophthalmic infection were found in the literature search.

CONCLUSIONS

Ophthalmic blastomycosis infections can cause rapid, complete vision loss. Prompt treatment is required, but infections are uncommon and usually are misdiagnosed, often because of lack of biopsy results. Tissue must be biopsied, cultured, or both for a definitive diagnosis. Because virtually all blastomycosis cases begin in the lungs, a chest radiograph or computed tomographic scan should be obtained. Any questionable lung lesion should be biopsied to corroborate possible ophthalmic disease.

Orbital cellulitis, panophthalmitis, and ecthyma gangrenosum in an immunocompromised host with pseudomonas septicemia

PURPOSE

To describe a case of Pseudomonas aeruginosa septicemia complicated by orbital cellulitis, panophthalmitis, and ecthyma gangrenosum.

DESIGN

Observational case report.

METHODS

An immunosuppressed 62-year-old man developed an unusual skin rash and a painful, swollen right eye with decreased vision. He had myelodysplastic syndrome and P. aeruginosa septicemia. The skin rash manifested as ecthyma gangrenosum. Metastatic orbital cellulitis and panophthalmitis was diagnosed.

RESULTS

Despite intravitreal and topical gentamicin, the patient eventually required enucleation.

CONCLUSIONS

This case represents a rare combination of events: an immunocompromised man developed pneumonia, P. aeruginosa septicemia, and endogenous seeding of the Pseudomonas to the skin, orbit, and eye. Early recognition of endogenous ophthalmic disease is imperative. The prognosis of combined orbital cellulitis and panophthalmitis is poor.

Current perspectives on ophthalmic mycoses

Fungi may infect the cornea, orbit and other ocular structures. Species of Fusarium, Aspergillus, Candida, dematiaceous fungi, and Scedosporium predominate. Diagnosis is aided by recognition of typical clinical features and by direct microscopic detection of fungi in scrapes, biopsy specimens, and other samples. Culture confirms the diagnosis. Histopathological, immunohistochemical, or DNA-based tests may also be needed. Pathogenesis involves agent (invasiveness, toxigenicity) and host factors. Specific antifungal therapy is instituted as soon as the diagnosis is made. Amphotericin B by various routes is the mainstay of treatment for life-threatening and severe ophthalmic mycoses. Topical natamycin is usually the first choice for filamentous fungal keratitis, and topical amphotericin B is the first choice for yeast keratitis. Increasingly, the triazoles itraconazole and fluconazole are being evaluated as therapeutic options in ophthalmic mycoses. Medical therapy alone does not usually suffice for invasive fungal orbital infections, scleritis, and keratitis due to Fusarium spp., Lasiodiplodia theobromae, and Pythium insidiosum. Surgical debridement is essential in orbital infections, while various surgical procedures may be required for other infections not responding to medical therapy. Corticosteroids are contraindicated in most ophthalmic mycoses; therefore, other methods are being sought to control inflammatory tissue damage. Fungal infections following ophthalmic surgical procedures, in patients with AIDS, and due to use of various ocular biomaterials are unique subsets of ophthalmic mycoses. Future research needs to focus on the development of rapid, species-specific diagnostic aids, broad-spectrum fungicidal compounds that are active by various routes, and therapeutic modalities which curtail the harmful effects of fungus- and host tissue-derived factors.

Enucleation

The three most common indications for enucleation are intraocular malignancy, trauma, and a blind, painful eye. Recommending enucleation is one of the most difficult therapeutic decisions in ophthalmology. In some cases of malignancy, cryotherapy, laser photocoagulation, diathermy, chemotherapy, and radiation therapy may be viable alternatives to surgery. When surgery is chosen, evisceration or exenteration may be alternatives to enucleation. Once the decision is made to perform enucleation or evisceration, the surgeon must choose from several types of implants and wrapping materials. These devices can be synthetic, autologous, or eye-banked tissues. With certain implants, the surgeon must decide when and if to drill for subsequent peg placement. In this review, the authors discuss choices, techniques, complications, and patient consent and follow-up before, during, and after enucleation. Controversies and results of the Controlled Ocular Melanoma Study are summarized.