Infectious Disease Update: Year in Review

Andrew Blauvelt, MD

Dr Blauvelt presented an update on important information and data on infectious diseases that were published in some of the top tier medical journals in 2012 and their clinical implications for the practicing dermatologist.

 Clinical Pearls
  • Look for Staph. Aureus infection in and around implantable electronic devices-these were associated with hematomas and wound healing; recommended treatment was complete removal of the device and antibiotic therapy
  • Be aware of possible bacterial contamination in antiseptic products in the office; of note, antiseptic products are NOT required to be manufactured under sterile conditions (currently under review by the FDA)
  • Erythema migrans in persons with a history of Lyme Disease most likely represents reinfection and not recurrent disease
  • Tattoos may be infected with mycobacteria contaminating the tattoo ink. Tattoo ink does not have to be manufactured in sterile conditions. M. Chelonae was found recently in a batch of tattoo ink. Diagnose, treat, and report accordingly
  • Travel history is important for a sick patient with cutaneous abscesses.  Meloidiosis, a disease caused by environmental (in soil) gram-negative bacillus Burkholderia pseudomallei, presents with multiple cutaneous abscesses and pneumonia. It has a 40% mortality rate.
What about viruses?
  • Adults born from 1945-1965 should receive one time testing for the hepatitis C virus without prior assessment of HCV risk (recommendation from the CDC)
  • All persons identified with HCV infection should receive brief alcohol screening/intervention as indicated followed by an appropriate referral to a specialist
  • Clinical data and ex vivo experiments that show pre-exposure prophylaxis with anti-HIV drugs can block subsequent infection; however, controversy exists over ethics, practicality, and cost
  • Genital herpes simplex virus 2 (HSV-2) enhances sexual transmission of HIV
  • Antiviral medication for the treatment of HSV-2 using short courses of high-dose acyclovir and valacyclovir (1 gram TID) may decrease outbreaks, but does not prevent  subclinical HSV-2 genital shedding of the virus.  The therapy does decrease shedding by about 50% but the rate of breakthrough shedding was 16-20 episodes/year. Novel therapies need to be developed to block shedding
More Clinical Pearls
  • Live vaccines may be safer in the setting of biologic therapy than previously believed.  In a study of MCR patients receiving biologics, 633 patients were inadvertently vaccinated with the herpes zoster vaccine. None developed varicella or zoster.
  • In addition to previously identified in EVER1 and EVER2 genes, epidemodysplasia verruciformia may be caused by a genetic defect in RHOH which leads to T cell defects
  • Injectable corticosteroid products may be contaminated during the compounding or manufacturing process
  • Natural disasters can lead to unusual medical conditions.  Mucormycosis, caused by infection with ubiquitous molds in soil and decaying wood, resulted in 13 cases of mucormycosis resulting in 5 deaths in storm affected areas. The median number of wounds through which the mold penetrated was 5.
  • Bilateral leg lymphedema, which can lead to elephantiasis verrucosa nostra, is associated with obesity (and not filariasis in non-endemic areas).  The average BME was 51.4.
  • Topical 0.5% Ivermectin lotion is a promising new therapy for head lice. In two large studies, a single application of 0.5% ivermectin applied to dry hair, left for 10 minutes, and then washed off resulted in nearly 75% of patients being louse free at day 15.  Nit combing in not necessary because ivermectin if both pediculocidal and ovacidal.
Aditya Gupta, MD, PhD

Dr Gupta, one of the leading authorities in the world on fungal infections, provided the audience with an update onychomycosis and how dermatologists can improve upon the management of this condition.  Dermatologists should be aware of the prevalence of onychomycosis and this may help practitioners understand why patients may fail certain therapies. There are various therapies available for onychomycosis including oral therapy, topical therapy, and devices.

Oral Therapy

Terbinafine is probably the gold standard for the management of onychomycosis. Dr Gupta and his colleagues studied various terbinafine dose regimens and found that 2 pulses 250mg/day 4 weeks on/4 wks off/4 wks on appeared to have the best outcomes; however, there was not a significant difference between continuous and pulsed regimens.  It is important that dermatologists understand the existing data on the various antifungal medications currently available in order to apply this information into clinical practice.

Topical Therapies

The nail plate is the greatest barrier when treating fungal infections. Currently, ciclopirox is the only topical therapy approved in the United States. However, there are emerging therapies currently under investigation.

Device Therapy

There are lots of questions about laser therapy. Podiatrists seem to use laser therapy quite often; yet, dermatologists continue to raise questions about their effects and how they actually work. Laser therapy poses the same challenges as those of topical therapies. To date, there is only one published trial (n=13) and the study demonstrates an efficacy rate of 51%. More studies are needed to determine if laser treatment is effective.

In conclusion, dermatologists need to recognize the importance of the choice of agent for onychomycosis and identify other important management strategies that may help to improve the outcomes of their patients.