Research Offers Possible Alternative to RF-CL Combo for Hidradenitis Suppurativa

A novel treatment could offer an alternative to clindamycin (CL) in combination with rifampicin (RF), which comes with concerns of developing resistant bacteria due to long-term use.

Clindamycin (CL) monotherapy may be a viable treatment option for patients with hidradenitis suppurativa (HS), particularly those with mild or moderate disease, according to new study findings published in Annals of Dermatology.

If further studies confirm the safety and efficacy of CL monotherapy, the treatment could offer an alternative to CL in combination with rifampicin (RF), which comes with concerns of developing resistant bacteria due to long-term use.

“Though HS is not primarily an infectious disease, the RF-CL combination is recommended as first-line therapy in moderate to severe HS for their antimicrobial, anti-inflammatory, and immune-modulatory properties,” wrote the researchers, noting that various bacterial species have shown to be involved in the disease. “However, there are still several concerns regarding long-term RF-CL combination treatment.”

According to the researchers, despite concerns of drug-resistant bacteria, as well as several adverse events associated with long-term use of the RF-CL combination, few studies to date have explored possible alternatives to the treatment.

In their retrospective single-center study, the researchers found that CL monotherapy was both safe and useful in 53 patients with HS after 8 weeks of treatment. Resistance to CL occurred in 15% of patients, which the researchers note was lower than a previously reported rate of 65.6%. They add that the presence of CL-resistant bacteria seemed to not have a significant impact on the efficacy of CL monotherapy.

Thirty-four of the patients had available efficacy data, and these showed that 61.76% achieved Hidradenitis Suppurativa Clinical Response (Hi-SCR). By stage, all patients with Hurley’s stage 1 disease, 80.0% of patients with Hurley’s stage 2 disease, and 52.17% of patients with Hurley’s stage 3 disease achieved Hi-SCR.

In addition, the treatment showed more favorable efficacy results in patients with mild or moderate disease compared with patients with severe or very severe disease, which the researchers say is in line with previous reports.

Across the full cohort of patients, 26.2% experienced an adverse event, 9 of which led to treatment discontinuation. These adverse events included diarrhea, occurring in 12 of the cases, as well as abdominal pain, skin rash, and elevated liver enzyme levels.

“Systemic CL monotherapy may be a safe and useful alternative to RF-CL combination therapy,” the authors concluded, “and no significant difference in the efficacy of the therapy depending on the presence of CL-resistant bacteria was observed.”

Still, they recommend future trials investigate their findings to confirm the results seen in this study.


An JH, Moon SJ, Shin JU, Kim DH, Yoon MS, Lee HJ. Clindamycin mono-therapy of hidradenitis suppurativa patients: a single-center retrospective study. Ann Dermatol. 2021;33(6):515-521. doi:10.5021/ad.2021.33.6.515