Dermatology in Review

Hensin Tsao, MD, PhD

Dr Hensin Tsao, Director of the Melanoma Clinic at Massachusetts General Hospital, lead off the 2013 Maui Derm meeting by providing the audience with an overview of the top stories in dermatology in 2012-2013.

New Observations
  • Melanoma is the 5th most common cancer in males and the 6th most common cancer in females affecting one in 36 men and one in 55 women. Melanoma incidence and mortality continue to increase, there is a disparity in survival among races (higher level of mortality in African Americans), and women seem to have better survival rates than men.
  • Another hot topic is that of blood-borne viral infections linked to tattooing. M. chelonae infection has been associated with tattoos. Molecular analysis showed M. chelonae was found in 11 clinical isolates and in an unopened bottle of ink. 18 out of 19 patients responded to macrolides and or doxycycline depending on sensitivities. Contamination likely occurred before distribution.
  • Sun avoidance is a crucial component of all skin cancer prevention campaigns. Scientists have studied the effects of direct light, diffuse light, and reflected light.  Modeling revealed that a large amount of diffuse UV radiation occurs. Recent studies indicate that direct UV occurs mostly on exposed sites during summer months; reflected irradiation occurs during winter months. SimuVex software estimates UV from various ambient sources. Diffuse radiation accounted for 75-85% of the annual sun exposure. It is not clear whether or not shading can protect against diffuse light.
  • 87% increased risk of melanoma if tanning [beds] are first used before age 35. Sunbeds account for about ten percent of melanomas in women and five percent in men. This is becoming a significant public health problem. Tanning bed use now contributes to about 10% of melanomas. Public health response is more aggressive these days, but we’re not there yet.
  • Murcormycosis is a rare infection caused by molds that are ubiquitous in soil, decaying wood and organic material. Immune incompetent patients are more susceptible. Outbreaks of rare saprophytic infections occur after catastrophes, such as tornadoes, have been reported. Infections need to be considered early so proper treatment with Amphotericin B can be instituted.
New Treatments
  • Most BCCs are removed by surgery or with radiation or topical therapies
  • The small molecule hedgehog pathway inhibitor is effective for metastatic advanced and generalized BCCs. Side effects are pretty significant, recurrences after drug discontinuation, and costs are limiting factors.
  • The emergence of resistance to first line antipediculicides complicates the public health problem of head lice. Ivermectin 0.5% (topical) for the treatment of head lice has a higher success rate versus the control vehicle. It is pediculocidal and ovacidal.  This means that nit combing post treatment is not necessary.
  • Targeted therapy for melanoma (Anti-PD-1 and Anti-PD-L1 antibodies) have demonstrated positive efficacy in tumor reduction and may be less toxic than ipilmumab.
  • The use of Sirolimus (rapamycin) has proven effective in secondary skin cancer in the transplant population.
New Insights
  • Germline and mosaic versions of cancer mutations lead to developmental and harmartomatous conditions. Sequencing these can lead to emerging treatment.
  • The increased use of antibiotics has lead to increased diarrhea. Duodenal infusion of donor feces for recurrent clostridium difficile has demonstrated positive efficacy and data suggest that fecal transfer is superior to vancomycin for recurrent C. difficile.
  • Biologics and small molecules are going to change the way we continue practice medicine.