Luis Garza, M.D., Ph.D., on possible chemical, dietary links to rising incidence of hidradenitis suppurativa

Hidradenitis suppurativa is becoming more common, and Luis Garza, M.D., Ph.D., a professor of dermatology at Johns Hopkins University School of Medicine, suspects that a chemical in the modern food supply may be behind the increase.

In an interview with Managed Healthcare Executive, Garza, an expert on hidradenitis suppurativa who says he has approximately 150 patients with the condition at given time, discussed a possible comparison to polychlorinated biphenyls (PCBs), mixtures of chlorinated compounds that were used as coolants and lubricants until they were banned as an environmental and health hazard in the 1970s.

People who had a systemic exposure to PCBS developed nodules, pus, and bumps in the underarms and groin — a presentation that, Garza says, resembles hidradenitis suppurativa.

Garza said he believes there may be chemical exposure now that’s tipping some vulnerable people to developing hidradenitis suppurativa, “we just have not discovered what it is.”

He and his colleagues think that chemical might be related to something in processed foods, because the rise in the number of people with the conditions roughly parallels the consumption of processed foods, Garza said. And, Garza added, there are some chemical overlaps between PCBs and bisphenols such as bisphenol A (BPA).

When concerns about harm from BPA started to emerge approximately 10 to 15 years ago, manufacturers began switching to BPA substitutes, and Garza said he wonders whether one of those substitutes could be the PCB-like trigger, although, he stressed, that has not been established.

The clues so far point to lifestyle rather than workplace exposure. Garza says colleagues in Japan have shared that hidradenitis suppurativa used to be very rare on the island of Okinawa, a classic “blue zone” known for people with long lifespans and healthful diets. But over the past 30 years, American fast food and processed food have proliferated around the U.S. military bases there, and physicians on the island are now seeing more hidradenitis suppurativa. Garza acknowledged that the connection needed more study but that it is consistent with disease having a link to dietary exposure.

In the meantime, he advises patients to avoid processed foods, including healthy-seeming factory-made products such as protein shakes that could be contaminated with triggering chemicals. He tells patients that if they can eat like it was the 1920s, before the PCB era.

Rising incidence is also part of how Garza came to focus on hidradenitis suppurativa. As a resident, he saw the disease so rarely that cases were brought to grand rounds, but over the years he saw more and more of them, Garza recalled. Realizing how little was known about the molecular biology of hidradenitis suppurativa, he launched research on the disease in his laboratory and took over the Johns Hopkins hidradenitis clinic from Ginette Okoye, M.D., who left to chair the dermatology program at Howard University.