People with hidradenitis suppurativa (HS), an inflammatory skin condition that causes painful, deep-seated abscesses in skin folds, are well aware of other health problems it can cause. Permanent scarring as well as depression and anxiety brought on by living with a chronic, visible disease are a few examples. There’s one potential complication of HS that isn’t so well known, though: squamous cell carcinoma (SCC). It’s a small risk, but one worth being aware of. If you’re living with HS, one of your best defenses against any complication is to learn all you can about it and use that information to fine-tune how you manage your condition. Here’s what you should know about the connection between HS and skin cancer. What Is Squamous Cell Carcinoma? Squamous cell skin cancers are malignant nonmelanoma growths that arise from a type of skin cell located in the outer and middle layers of the skin. After basal cell carcinoma, SCC is the second most common skin cancer, according to the Skin Cancer Foundation . It’s typically caused by excessive exposure to ultraviolet (UV) rays. Squamous cell cancer is highly curable, as long as it’s diagnosed and treated promptly. Around 2,000 people in the United States die each year from basal and squamous cell cancers combined, the American Cancer Society reports. “If left untreated, squamous cell cancer can become locally invasive, aggressive, and destructive to the skin and nearby tissue,” says Farah Succaria, MD , an assistant professor of dermatology at Johns Hopkins University School of Medicine in Baltimore. In other words, it can metastasize (spread) and cause serious and potentially fatal damage. What Makes SCC Different in Hidradenitis Suppurativa Again, SCC is most often caused by too much sun exposure. This may sometimes be the case for people with HS who develop SCC in areas of skin that aren’t typically hidden in skin folds or by clothing. Other factors may also play a role in how squamous cell cancer occurs and behaves when it’s associated with HS. Chief among them is inflammation, which can make any type of cancer worse, says Luis Andres Garza, MD, PhD , a professor of dermatology at Johns Hopkins University School of Medicine in Baltimore. The inflammation that happens in the body from HS may be part of the increased likelihood of squamous cell skin cancer, he adds. Certain treatments for HS may ratchet up the risk of SCC. Some HS medications suppress the immune system, for example, which is linked to a higher risk of developing skin cancer, says Dr. Garza. One study , for example, found that immunosuppression is an independent risk factor associated with worse outcomes in those who have cutaneous (skin) squamous cell carcinoma. Another unique factor of squamous cell carcinoma in HS is location. “HS primarily occurs in places where skin rubs on skin,” says Rita Pichardo, MD , a dermatologist at Atrium Health Wake Forest Baptist in Winston-Salem, North Carolina, who runs an HS clinic. “These regions can be chronically inflamed for many years. That makes certain regions in the body — the vulvar, perianal, and perineal areas — especially prone to developing skin cancer.” In fact, a review of studies published in 2021 in the International Journal of Dermatology looked at SCC as a result of HS and found that the most common sites of the cancer were the buttocks, the perianal region, and the genitals. SCC may also be more likely to spread and even cause death in people with HS than in otherwise healthy people. In the 2021 review, for instance, in more than half of the people (mostly male) with HS who developed squamous cell growths, the cancer metastasized. Over 40 percent of them had a recurrence of SCC, and more than 58 percent ultimately died of either metastases or sepsis. Lastly, chronic wounds — what the persistent lesions that characterize HS essentially are — are associated with a type of skin cancer that frequently takes the form of squamous cell carcinoma, adds Garza. Known as Marjolin’s ulcer, this rare, aggressive skin cancer develops in scar tissue, chronic ulcers, and areas affected by inflammation. Catching SCC Early Squamous cell cancer may be particularly problematic in HS, because the lesions caused by both conditions often look similar, so skin cancer may be overlooked, suggests a case study published in 2020 in Advances in Skin & Wound Care . For this reason, it’s especially important for people with HS to see a dermatologist every 6 to 12 months for a full-body cancer screening, says Dr. Pichardo. Even then, “It can be difficult, even for a doctor, to spot skin cancer just by looking at it,” notes Garza, “so we’ll perform a biopsy on anything we find that’s concerning.” Self-exams between skin checks are also a good idea. About once a month, examine your skin, using a mirror for areas you can’t see otherwise, to look for anything that seems different or unusual, advises Garza. “Trust your intuition,” he adds. “If something looks weird or you’ve never noticed it before, bring it to the attention of your doctor.” Some specific symptoms to look for: “A place on your skin that bleeds by itself is a red flag,” says Garza. It’s not uncommon for people who have HS to notice a lot of pus coming out of their skin, but if there tends to be more blood in one area of the skin, that needs to be checked out. Additionally, within an area of HS lesions that are improving with treatment, if there’s a bump that won’t go away and/or looks unusual, talk to your doctor, says Garza. Tips for Preventing Skin Cancer There are several simple ways to keep the already small risk of skin cancer associated with HS to an absolute minimum. Get diagnosed as soon as possible . If you have symptoms of HS , such as a painful nodule that looks like a cyst or a boil in your armpit, inner thigh, or groin, see a dermatologist right away. The sooner you start treatment, the less inflammation you’ll experience over time. Follow your management plan to a T . “There are no studies that show with certainty whether or not managing HS well can reduce associated skin cancer risk, but it’s probably the case,” says Garza. Prevent sunburn . This means staying out of the direct sun when possible, wearing sunglasses and a hat with a brim, and using sunscreen on exposed skin (but not on HS lesions that are covered or hidden) even on cloudy days. Most important, says Garza, “If you have HS, it’s good to be aware of the skin cancer risk so that you can be on the lookout and see your dermatologist regularly, but I recommend focusing on your overall health. That includes managing your disease and maintaining a healthy diet and overall healthy lifestyle.”
