On the Frontline: Fighting Infectious Disease

In September 2014, Stephen Tyring, MD, PhD, a dermatologist and author of Tropical Dermatology, was giving a lecture about emerging arboviruses in the western hemisphere. The audience response was professional interest, but not much more. “People said, ‘That’s nice, but when are we ever going to see it?,” he recalled. Then doctors in a Dallas hospital made a diagnosis of Ebola for the first time ever. 

“No one ever worried about Ebola in the United States until that first patient,” said Dr Tyring, who works at McGovern Medical School at The University of Texas Health Science Center in Houston. “No one worries about a virus until it starts spreading.” By the time an infectious disease like Ebola has been diagnosed, however, the health care community is already playing catch up trying to prevent it from spreading further. Dermatologists are likely to be on the frontline in many of these cases, since many viruses have dermatologic manifestations: erythema, rashes, warts, skin cancers. 

With the number of viral outbreaks climbing, knowing how to recognize, contain, treat—and best of all, prevent—these often-deadly diseases is crucial to everyone working in dermatology. 

Derms on the Frontline 

Dermatologists often end up involved in infectious disease cases because so many viral pathogens manifest with dermatologic symptoms. There are 2 main reasons this is believed to be the case, said Dr Tyring. One is a direct effect in which some viruses cause a rash because the viral infection that enters cells continues to replicate until it spills out of the nerve cells and into the skin cells, causing a rash. Human papillomavirus (HPV) is one example. In other cases, it is the indirect result of a patient’s own immune response to a virus that can cause physical manifestations on the skin. 

Regardless of the trigger, a patient who presents with a rash, bug bite, erythema, or any number of other skin abnormalities may visit a dermatologist first. Other, more traditional viral symptoms, such as a fever, chills, or vomiting accompanying skin issues are signs that the problem may be viral in nature. 

Far-Flung Factors 

While many infectious diseases have been eradicated, or well controlled, within the United States, several factors are leading to recent increases. Travel outside the United States is a major one. Since 2006, more than 200 cases of chikungunya, a mosquito-borne illness, have been reported in the United States, but mainly in people who had travelled to other countries.¹ Likewise, there have been more than 5000 travel-related cases of the Zika virus in the United States, but only a handful of other sources of transmission. “A few years ago, people were afraid to travel to anyplace tropical because of Zika,” said Dr Tyring. “Pregnant women were advised not to travel to areas where Zika outbreaks were happening.” 

These days, a lot more people regularly participate in international travel, for business and for pleasure. Members of the military or other professions that require frequent foreign travel can be at risk. “It’s good for every dermatologist to be on the lookout, even if we’re not in a current outbreak,” Dr Tyring said. “We’re just 2 years out from an endemic Zika outbreak.” 

Asking about a patient’s recent travel history, and any unprotected sexual contact with someone who has recently travelled to active transmission areas, is an important part of a clinical visit in patients who present with 2 or more of the disease’s major signs or symptoms (see Table). 

A Global Problem 

Changing environmental factors also play a role in the proliferation of viruses. In general, said Dr Tyring, warmer climates foster viruses—as well as the insects that carry and transmit them—which is why many originate or thrive in tropical locales. Habitat changes that can impact the food chain are also a factor. In the northeast, the deaths of millions of bats, one of the largest natural predators of mosquitoes, has been a concern. 

Additionally, some viral infections, including Zika, may mutate, then the new versions may present clinically in a slightly different way, making diagnosis a challenge, or respond differently to treatment. One virus that made a recent recurrence in a different form is the coxsackievirus, known for causing hand-foot-and-mouth disease in children. “It’s normally nothing too worrisome but adults started getting a new strain (ie, A6) and they got really, really sick,” said Dr Tyring. “In addition to the characteristic blisters and fever, some people were hospitalized and their fingernails started sloughing off. No other coxsackievirus causes that.” 

Vaccination Nation 

One of the other major reasons doctors are seeing a return of many infectious diseases that were eradicated long ago, such as measles, mumps, and rubella, is because patients are failing to get vaccinated. The current measles epidemic in the United States, the worst in this century, is due to some parents’ illogical fear of vaccines. “Eighty thousand people die of influenza in the United States each year,” said Dr Tyring.² “People are still afraid to get the shot.” 

The development of a vaccine to protect against HPV was a huge advancement and especially significant given that it prevents 9 different strains of the virus, 7 of which are oncogenic. FDA testing has proven its effectiveness and expanded its use from young women and girls to men and women up to age 45. “If insurance will pay for it, why not get it?” said Dr Tyring. “The vaccine is 99% effective.” Additionally, any serious side effects of vaccines that have been reported were not related to the contents of the vaccine but the needle (ie, the injection). 

There is also a new, more effective vaccine for shingles, a disease caused by the same virus that causes chickenpox, varicella zoster. The Centers for Disease Control and Prevention recommends it for people age 50 and older because of its greater efficacy (it is 97% effective). It also appears to have greater durability than previous vaccines. 

“The average practicing dermatologist sees HPV manifestations every day and shingles every day,” said Dr Tyring. “They should counsel patients about the benefits of these vaccines, especially in the case of HPV before they become sexually active. The bottom line is, it’s better to prevent than lament.” 

References 

1. First chikungunya case acquired in the United States reported in Florida [news release]. Atlanta, GA: Centers for Disease Control and Prevention; July 17, 2014. https://www.cdc.gov/media/releases/2014/p0717-chikungunya.html. Accessed March 11, 2019. 

2. National press conference kicks off 2018-2019 flu vaccination campaign. Centers for Disease Control and Prevention website.https://www.cdc.gov/flu/spotlights/press-conference-2018-19.htm#ref1. Updated September 27, 2018. Accessed March 11, 2019.