Zoster Ophthalmicus

  • Herpes zoster (or shingles) is due to reactivation of endogenous latent VZV within the sensory ganglia.
  • Rash typically starts as erythematous papules that evolve into grouped vesicles and can become more pustular and hemorrhagic by day 4 in a single or multiple dermatome pattern.
  • Lesions tend to crust by days 7-10 and are considered no longer infectious.
  • Herpes zoster ophthalmicus is a potentially serious sight-threatening condition linked to VZV reactivation of trigeminal ganglion.
  • Typically involves the ophthalmic branch of cranial nerve V.
  • 50-72% of patients with ophthalmicus will have direct ocular involvement: conjunctivitis, episcleritis, iritis, keratitis, lid droop.
  • Vesicular lesions on nose are associated with high risk of zoster ophthalmicus – Hutchinson’s Sign.
  • Typically it is a clinical diagnosis but can perform Tzanck smear of vesicle, viral culture, or VZV PCR.
  • Ophthalmology involvement is highly recommended.
  • Antiviral therapy: oral famciclovir or valacyclovir for 7-10 days; if retinitis involvement use acyclvoir 10mg/kg IV q8h (Johns Hopkins Antibiotic Guide)
  • Adjunctive therapies: cool compresses, topical steroids (ex. Loteprednol), systemic steroids used when there’s significant edema and concern for pressure on optic nerve in periorbital region.

Radiation Pneumonitis

Risk:

  • Thoracic or neck irradiation for the treatment of malignancy (eg, breast, laryngeal, lung, hematologic)
  • Method of irradiation
  • The volume of irradiated lung
  • Total dosage and frequency of irradiation
  • Associated chemotherapy

 

Symptoms:

  • General: dyspnea, cough, chest pain, fever, and malaise
  • Subacute: usually develop approximately four to twelve weeks following irradiation
  • Late or fibrotic: radiation pneumonitis develops after six to twelve months

Physical examination:

  • Pulmonary: crackles, a pleural rub, dullness to percussion, or may be normal.
  • Skin erythema may outline the radiation port but is not predictive of the occurrence or the severity of radiation pneumonitis

Diagnosis:

  • Careful exclusion of other possible diagnoses, such as infection, thromboembolic disease, drug-induced pneumonitis, pericarditis, esophagitis, tumor progression, or tracheoesophageal fistula, is key.
  • Imaging:
    • Subacute: chest radiograph may show perivascular haziness. CT chest may show patchy alveolar ground glass or consolidative
    • Chronic: volume loss with coarse reticular or dense opacities. A straight line effect, which does not conform to anatomical units but rather to the confines of the radiation port, is virtually diagnostic of radiation-induced lung injury.

Treatment:

  • Symptomatic: typical treatment is prednisone (at least 60 mg/day) for two weeks, followed by a gradual taper
  • Asymptomatic: do not initiate treatment unless symptoms become bothersome or pulmonary function declines by more than 10 percent.
  • Patients who have established fibrosis due to prior irradiation are unlikely to benefit from glucocorticoid therapy

Ask the Expert: Dr. Bedimo on HCAP

You are on call and get a call from the ER for possible pneumonia in a patient that resides in a nursing home. How do you approach the choice of antibiotic therapy? Should this be treated as community-acquired pneumonia, or health-care associated pneumonia?

Dr. Bedimo, Chief of the Infectious Disease Division at the North Texas VA Medical Center, notes the following: “The ATS/IDSA guidelines indeed include nursing homes in the definition of Health Care Associated Pneumonia (Am J Respir Crit Care Med. 2005;171(4):388).

Healthcare-associated pneumonia (HCAP) is defined as pneumonia that occurs in a non-hospitalized patient with extensive healthcare contact, as defined by one or more of the following:

  • Intravenous therapy, wound care, or intravenous chemotherapy within the prior 30 days
  • Residence in a nursing home or other long-term care facility
  • Hospitalization in an acute care hospital for two or more days within the prior 90 days
  • Attendance at a hospital or hemodialysis clinic within the prior 30 days

However, the issue is whether these settings indeed increase the likelihood of multi-drug resistant pathogens such as MRSA and MDR Pseudomonas.  The above guidelines are dated, and there’s recent controversy over the topic.  So, newer guidelines (due anytime now) might change to likely exclude nursing home residents without recent hospital contact…”

 

 

Sepsis: More Complicated Than We Think

Yesterday at noon conference, Dr. Cutrell (Infectious Disease Division), referred to several articles that have reexamined sepsis including its mechanisms and management. Check out the articles below that Dr. Cutrell referred to:

Article written by Dr. Suffredini and Dr. Munford (former UTSW resident and faculty) in JAMA from 2011 reviewing past therapies for sepsis and potential future projects:

http://www.ncbi.nlm.nih.gov/pubmed/21750297

Article written in Proceedings of the National Academy of Sciences in the United States of America in 2013 that reevaluates the utility of murine models in understanding human diseases. Followed by a link from The New York Times that addresses this same topic:

http://www.ncbi.nlm.nih.gov/pubmed/23401516

http://www.nytimes.com/2013/02/12/science/testing-of-some-deadly-diseases-on-mice-mislead-report-says.html?pagewanted=all

Big thanks to Dr. Cutrell for the links!