Posts for: March, 2015
Please enjoy the video of Integrated Dermatology of Tidewater at the Shamrock Marathon Fitness and Wellness Expo 2015:
Contact Dermatitis by Jonathan Schreiber, MD, PhD
“Leaves of three let it be.” Most of us have probably heard this, and many of us have had first hand experience with poison ivy. The rash that develops after contact with this plant is extremely uncomfortable and can last up to two weeks from the initial exposure.
Toxicodendron radicans, formerly known as Rhus toxicodendron produces an oil called urushiol, which is the substance that causes the allergic reaction. The itching and rash generally develop a day or two after the exposure. The onset of symptoms can be delayed even more in some cases. Redness and clusters of blisters, which can range in size from a few millimeters to several centimeters, develop at the affected sites. The rash is often spotty, or in lines created by streaks of oil that get transferred to a person’s skin as he or she walks by the plant, brushing against it.
If you know you will be in an area that has poison ivy, it is best to minimize exposed skin in order to avoid contact with the plants. Keep in mind that if the toxic oil gets on your clothing, you can develop the rash from contact with the affected clothing. This includes shoes and shoe laces. The oil is quite stable and can last for months, and even years on inanimate objects. Oil can also be transferred to people from pets that have been in contact with the plants.
After a suspected exposure, immediately wash the affected areas with soap and water. Also be sure to wash all clothing, including shoes, that may have been in contact with the plants, as you don’t want to re-expose yourself later on.
Despite your best effects, a rash may still develop. The rash can be treated with hydrocortisone and/or calamine lotion. Antihistamines such as benadryl (diphenhydramine), allegra (fexofenadine) and claritin (loratatine) can help decrease the symptoms. Keep in mind that diphenhydramine can cause drowsiness, so do not take this medication if you need to remain alert. Cool compresses can help alleviate the symptoms. If you develop significant swelling or trouble breathing, you should seek medical attention right away. Physicians can prescribe medications much stronger than those you can get over the counter to treat your symptoms.
You cannot spread poison ivy from one area of your body to another, or to another person. The rash only develops where urushiol contacts the skin. You can only spread the rash by moving the oil from one area to another, but once you have washed off the oil, you are no longer in danger of contaminating new areas.
Even if you believe you are not allergic to poison ivy, it is best to avoid the plant, as you can develop the allergy after repeated exposures. Some people are also allergic to mangos and cashew nuts, as the rind of the mango fruit, and the shells of cashew nuts contain chemicals similar to those in the urushiol.
Sun Exposure in Adulthood Can Be Risky
SAN FRANCISCO — Exposure to the sun during adulthood might cause more nonmelanoma skin cancer than exposure during childhood, a new study suggests.
In fact, women who lived in the southern latitudes of the United States as adults but not as children were 39% more likely to get nonmelanoma skin cancer than women who lived in northern latitudes.
This finding contradicts previous reports, said Katherine Ransohoff, a medical student at Stanford University in California. It is commonly thought that "it's childhood exposure that's important," she told Medscape Medical News here at the American Academy of Dermatology 73rd Annual Meeting.
Her team evaluated longitudinal data from the Women's Health Initiative, which involved 161,808 generally healthy postmenopausal women in the United States.
Among the data collected was residential history, which the team used as an indicator of sun exposure. They hypothesized that exposure during childhood "would have a greater impact on skin cancer risk than adulthood exposure," Ransohoff said.
In a subset of 56,000 white women during a median follow-up period of 11.9 years, 518 (0.9%) developed melanoma, as determined by medical records, and 9195 (16.3%) developed nonmelanoma skin cancer, as determined by the women's own annual reports.
Women's Health Initiative Data
The investigators assumed that women who lived south of the 37th parallel during the first 15 years of their life were exposed to more ultraviolet light than those who lived north of that.
The team also looked at data collected on behavior such as using sunscreen and wearing a hat, and the amount of time spent outdoors as a child and as an adult.
"This was important because we needed to adjust for behavioral variables, which may vary depending on location," Ransohoff explained.
They also adjusted for the women's age, education, body mass index, physical activity, history of melanoma and nonmelanoma skin cancer, skin reaction to the sun, vitamin D intake, alcohol use, and smoking status.
Women who lived in northern latitudes their entire lives, and were therefore considered to have low sun exposure during childhood and adulthood, were used as a reference group.
Not surprisingly, the risk for nonmelanoma skin cancer was significantly higher in women with high sun exposure during childhood and adulthood than in the reference group (OR, 1.12). However, the fact that the risk was even higher for women with low exposure during childhood and high exposure during adulthood than in the reference group (odds ratio [OR], 1.39) was a surprise, said Ransohoff.
"The lesson from this is not to retire to Florida," she joked.
The risk for melanoma was not significantly different between the groups. It might be that there were not enough melanoma cases for the statistical analysis to uncover differences in risk, Ransohoff reported.
In addition, "we are not able to account for cloud cover and altitude that affected the amount of ultraviolet light that reached the surface," said Ransohoff.
However, geography is a more reliable indicator of ultraviolet light than recall, and the size of the sample gave the study an unusually good statistical power, she said.
"Our next step is to convert to more nuanced measures of ultraviolet exposure," she added.
After the presentation, a member of the audience asked whether the investigators had separated statistics on basal cell carcinoma from those on squamous cell carcinoma.
Session moderator Sewon Kang, MD, from Johns Hopkins University in Baltimore, asked if the data suggest a protective effect of exposure to ultraviolet light in childhood.
"There are some data on the protective effects of early-life ultraviolet exposure," said Ransohoff. "I think work with more cases could shed light on whether that's true."
"More work needs to be done. I don't think we should somehow lower the protections in childhood based on this work," he said.
Dr Kang and Ms Ransohoff have disclosed no relevant financial relationships.
American Academy of Dermatology (AAD) 73rd Annual Meeting: Abstract F025. Presented March 20, 2015.
Sunscreen by Jonathan Schreiber, MD, PhD
Finally, it is time to dust off the Roleez, grab the surf board, find those boogie-boards, and see if the old beach chairs will still open up. While sorting through your beach tote, you may run across old bottles of sunscreen. Are they still good? There should be a date on the bottle, listed as a month and a year. If you can’t find the date, can’t read the date, or if the product in the bottle has separated into a distinct liquid and solid layer, or has become discolored, it is time to toss the bottle.
Even if you find some sunscreen that appears intact, this is the time to stock up for the summer. Sunscreen has been shown to decrease the risk of skin cancer, and slow the photo-aging process, which contributes to unwanted wrinkles and dark spots.
Look for a sunscreen that has an SPF of 30 or higher. The SPF, or sun protection factor, is a multiplier that compares the time it takes to develop a sunburn with the product compared to without the product. Therefore, with an SPF of 30 applied properly, it would take 300 minutes to develop a sunburn with the sunscreen compared to 10 minutes without it.
Why do we need so much protection? People rarely apply the amount of sunscreen required to achieve the labeled SPF. When sunscreens are tested, a standard thickness is used; however, in real world applications, people rarely use enough to achieve even half the thickness used in the testing laboratories. In fact, you would need to use 1oz or one fourth of a standard bottle to achieve the rating on the bottle. That is why physicians changed their recommendation of an SPF of 15 to an SPF of 30. Using a higher SPF provides reasonable protection, even when the product is applied in a thinner film than is used in laboratory testing conditions.
Look for a sunscreen that says “broad spectrum,” or UVA and UVB protection. UVB causes sunburns. Older sunscreens only protected people from UVB. We now know that UVA can contribute to sun damage and aging skin. Agents that block UVA are zinc oxide, titanium dioxide and parsol 1789, also known as avobenzone. Be sure your sunscreen contains at least one of these agents to protect you from UVA. There are other UVA blockers that are currently available in other countries, and may eventually make their way to the United States.
Remember, you can still get a suntan, and even a sunburn while using sunscreen. Be sure to apply sunscreen before you go out, and then every two hours while out in the sun. It is a good idea to reapply sunscreen after spending time in the water, even if the sunscreen is labeled water resistant. Protective clothing, such as rash guards and hats, as well as umbrellas and canopies will also help you to safely extend your time outdoors.
FRIDAY, March 13, 2015 (HealthDay News) -- The first genetic factors associated with the skin disorder rosacea have been identified by researchers.
More than 16 million people in the United States have rosacea, an incurable skin condition that causes symptoms such as redness, visible blood vessels and pimple-like sores on the face, the researchers said.
Many people with rosacea have stinging, burning or increased sensitivity in affected areas of the skin.
For the study, researchers analyzed genetic data from more than 46,000 consenting customers of the U.S.-based genetic testing company 23andMe. More than 2,600 of those people had been diagnosed with rosacea.
The investigators identified two genetic variants strongly associated with rosacea among people of European ancestry.
However, the association seen in the study does not prove a cause-and-effect link.
The genetic variants are in or near the HLA-DRA and BTNL2 genes, which are associated with other diseases, including diabetes and celiac disease, according to Dr. Anne Lynn Chang, from the Stanford University School of Medicine in California, and colleagues.
The study was published recently in the Journal of Investigative Dermatology.
The American Academy of Family Physicians has more about rosacea.
SOURCE: Journal of Investigative Dermatology, news release, March 10, 2015