(Reuters Health) - The number of dermatologists per capita in the U.S. has surged more than 20 percent since the mid-90s, but a new study suggests access to care may have improved more in cities than in rural areas.

Nationwide between 1995 and 2013, the number of dermatologists rose 21 percent, from 3.02 for every 100,000 people in the population to 3.65 for every 100,000 residents, researchers report in JAMA Dermatology. Over that time, however, the chasm between urban and rural America widened.

In rural areas, from the start of the study to the end, the proportion of dermatologists in the population increased from 2.63 to 3.06 per 100,000 residents. Gains were more pronounced in metropolitan areas, where the proportion of dermatologists rose from 3.41 to 4.03 per 100,000.

“We also found that the age of dermatologists in rural areas is increasing faster due to younger dermatologists preferring to work in urban areas,” said lead author Dr. Hao Feng of the Laser & Skin Surgery Center of New York.

“Ultimately, this workforce disparity affects patient outcomes negatively for those in underserved areas where they do not have easy access to dermatologists,” Feng said by email.

The shortage of dermatologists in many rural communities may mean people delay skin cancer screenings or miss them altogether, said Feng, who did the research while at the New York University School of Medicine. This might lead more people with melanoma, the most lethal form of skin cancer, to be diagnosed when it’s more advanced and difficult to treat or mean patients face long waits for care after a melanoma diagnosis.

“The key to surviving melanoma is early detection,” Feng added. “If patients can’t get in to see a dermatologist about a melanoma, it will continue to grow and potentially spread and become fatal.”

As the U.S. population ages, the need for access to dermatologists will only increase, the study team notes.

Beyond caring for people with skin cancer, dermatologists are also seeing a growing number of people with inflammatory skin disorders that can severely limit quality of life without proper treatment.

Consumer demand for dermatologists is also increasing as more Americans seek turn to skin specialists for cosmetic procedures designed to help them look more youthful.

To examine geographic trends in the distribution of dermatologists, researchers examined county-level workforce data spanning almost two decades.

The proportion of counties nationwide with no dermatologists fell slightly, from 71 percent at the start of the study to 69 percent by the end.

Dermatologists were more likely to work in affluent, urban counties with a higher concentration of primary care physicians and nurse practitioners, the analysis found.

The study wasn’t designed to prove whether or how geography might directly impact where dermatologists choose to work or if access to these specialists directly impacts patient outcomes.

Still, the dearth of dermatologists in rural areas may mean that more patients who need these specialists instead get seen by nurse practitioners, primary care physicians, or even physician assistants who aren’t skilled at diagnosing or treating cancer and other skin conditions, said Dr. James Dinulos of Seacoast Dermatology in Portsmouth, New Hampshire, and the Geisel School of Medicine at Dartmouth in Hanover.

“These other practitioners are being asked to tackle the same skin issues a seasoned dermatologist would, but with very little if any formal dermatology training,” Dinulos, who wasn’t involved in the study, said by email.

“This can result in delayed or misdiagnoses, ineffective treatments or unnecessary visits - particularly for skin cancer and eczema,” Dinulos said.

SOURCE: bit.ly/2x9CEzr JAMA Dermatology, online September 5, 2018.