“We wanted an evidence-based approach because the treatment of HS—until the publication of the European [Dermatology Forum] guidelines—had been based somewhat on trial and error for many physicians,” said Dr. Wayne Gulliver, chief medical officer and primary investigator at Newlab Life Sciences, a professor of medicine in the Department of Dermatology at Memorial University in St. John’s, N.L., and the study’s lead author.
“So we had all of these very small studies and nobody had really sat down and looked at them in an objective way to base treatments on level of evidence [LOE] and then giving them a strength of recommendation [SOR].”
Implementing recommendations Dr. Gulliver said another motivating factor for developing the “Evidence-based approach to the treatment of hidradenitis suppurativa/acne inversa, based on the European guidelines for hidradenitis suppurativa” was that the European guidelines are very comprehensive at 75 pages in length. Because clinicians might not have the time to read the full guidelines, he wanted to create an implementation paper, which is only nine pages.
The authors note that the diagnosis of HS should be made by a dermatologist or other healthcare professional with expert knowledge in HS. The treating physician should assess the disease severity using the Hurley classification of disease severity scale. They also strongly recommend the routine use of the DLQI and itch and pain assessment (Visual Analogue Scale).
First-line treatment options include topical clindamycin for mild HS, tetracycline for moderate HS, combination oral clindamycin and rifampicin for moderateto- severe HS, and adalimumab for patients with moderate-to-severe HS unresponsive or intolerant to oral antibiotics.
Topical clindamycin 1% received a LOE of IIb and SOR of B based on a randomized clinical control trial with 27 patients using clindamycin twice a day.
“By 12 weeks, which was the primary outcome, they did see significant decreases in pustules, [but] in terms of abscesses they did not see a significant reduction,” said Dr. Gulliver. “There was certainly a positive outcome from that study, but it was a single study. In terms of the evidence, [with only] one single small study, you really cannot base a whole lot on that.”
Tetracyline (500 mg b.i.d.) also received a LOE IIB and SOR B because the studies have had small sample sizes. Tetracycline has been compared with topical clindamycin in a double-blind, randomized, controlled trial with 46 patients and no significant differences were detected between the two treatment modalities, noted the investigators.
Combination clindamycin (300 mg b.i.d) and rifampicin (600 mg once daily or 300 mg b.i.d.) received a LOE of III and a SOR of C. While the trial was larger (190 patients) and showed an average of 50% improvement at 10 weeks, it was non-controlled, said Dr. Gulliver.
Adalimumab first HS treatment to undergo high quality study
Adalimumab (administered as 160 mg at week zero, 80 mg at week two, and 40 mg each week thereafter, starting from week four) was the therapy that received the highest LOE (Ib) and SOR (A).
“Prior to the studies that were done with adalimumab, we did not have large randomized control trials,” said Dr. Gulliver. “And so with adalimumab there were two major studies PIONEER I and PIONEER 2, which were large randomized control trials, and in those studies [there were about] 700 patients.” He added that the agent did not receive a LOE of IA because there has not yet been a meta-analysis study.
“So we do have a high quality study showing that it is superior to placebo and that it does work with data up to 52 weeks,” he said. “In terms of its study design, number of patients and outcomes, it is the first very high quality study that we have in this disease area.”
At week 12, the combined data from both trials was a 53.5% response rate and by week 36 the response rate increased to 58.6%. Adalimumab also showed decrease in pain, improvements of DLQI, and improvements in both work productivity and activity, according to Dr. Gulliver.
Infliximab was recommended (LOEIIa; SOR B) for patients with moderateto-severe HS as a second-line treatmentoption after failure of adalimumab.
Surgery should be considered in HS, noted Dr. Gulliver, for acute lesions—draining an abscess that has become too painful—and for managing scarring. The authors note that non-surgical methods rarely result in lasting cures and therefore “surgical treatment is a quite common and accepted therapeutic modality for HS.”
The researchers make recommendations on the use of radical surgical excision, de-roofing and skin-tissuesaving excision with electrosurgical peeling (STEEP), carbon dioxide LASER surgery, the use of 1064-nm neodymium-doped yttrium aluminum garnet (Nd:YAG) laser, and intense pulse light.
The authors also note that adjuvant therapies are also needed for treatment of HS including pain management, weight loss, tobacco cessation, treatment of super infections, and application of appropriate dressings.
“Pain control is important but we have very little studies or no studies on those specifically in HS. And dressings are very important because you have the draining, you have odor, and you have the surgical [component]. And so specifically for HS there have been no studies in terms of which surgical dressings to use specifically for HS,” said Dr. Gulliver, who referenced a recent paper led by Toronto dermatologist Dr. Afsaneh Alavi that discussed best practice for local wound care and topical management of HS (JAAD Nov. 2015; 73(5):S51-S61).
“[However], we have no specific studies on how to deal with HS and we are hoping that those will be coming in the future.”
Non-proprietary and brand names of therapies: adalimumab (Humira, AbbVie); infliximab (Remicade, Janssen).
Originally published in The Chronicle of Skin & Allergy (Sept. 2016; 22(6):8,12).