Hidradenitis suppurativa (HS) is a debilitating and chronic condition characterized by recurrent episodes of inflammation associated with the formation of abscesses, inflammatory nodules, pain, and drainage ultimately culminating in the formation of scarring in moderate to severe disease. HS affects more women than men in a ratio of approximately 3:1, and onset of the disease is typically after puberty. The axillae, breasts, groin, buttocks, and lower abdomen are common intertriginous regions which are affected by HS, and significant impacts on quality of life are reported in the literature.

The Hurley Staging system is commonly utilized to classify the severity of a patient's hidradenitis suppurativa. Stage 1 disease consists of one or more abscesses with no sinus tract formation or scarring. Stage 2 disease involves one or more widely separated recurrent abscesses, with formation of a sinus tract and/or scarring. Stage 3 involves multiple interconnected sinus tracts and/or abscesses throughout an anatomical area.

Histologic studies of HS suggest that follicular hyperkeratosis and obstruction is the primary event in the pathogenesis. Subsequently, there is rupture of the follicular infundibulum and a resulting inflammatory cascade. Despite recurrent episodes of purulent drainage, bacteria do not appear to play a primary role in the pathogenesis.

The traditional repertoire of treatment options for HS can be divided into medical and surgical options, however there is currently no cure for HS and treatments focus on symptomatic control. Medical treatments including topical and systemic antibiotics, hormonal agents, and biologic medications can successfully control symptoms however discontinuation of many of these is associated with relapses in disease symptoms. Conversely, surgical interventions such as traditional surgical excision performed in an operating room, or carbon dioxide laser excision performed under local anesthetic in an outpatient setting can induce long term symptom control however may not be appropriate for all patients considering the risk of general anesthesia, high cost of inpatient hospitalizations, and cumbersome healing process for procedures which heal by secondary intention. Despite numerous treatment options for HS, efficacious and non-invasive treatment options which result in long term remission of disease are needed to meet the needs of HS patients.

Subjects receive treatment every 2 weeks for a total of 22 weeks, 10 treatments. Subject treatment side will be randomized via computer generated assignments.

Ultrasound imaging will be utilized to assess abscesses, nodules, and sinus tracts at investigator discretion. Patient-reported outcome measures include DLQI and Pain VAS. Physician-reported outcome measures include: HS-PGA, IHS4, Hurley Staging, and HiSCR.

Inclusion Criteria:

1. Be at least 18 years old.
2. Have a diagnosis of Hurley stage I or II HS.
3. Patients must have bilateral HS in the axilla, groin, or breast.
4. Hurley stage 1 or 2 disease in either the axillae, groin, or inframammary locations.
5. At least 2 clinically observable lesions in the axilla, groin or breast.
6. Be able to understand the requirements of the study, the risks involved, and be able to sign the informed consent form.
7. Agree to follow and undergo all study-related procedures.

Exclusion Criteria:

1. No diagnosis of HS in the axillae or groin.
2. Tattoos located on proposed treatment locations.
3. Metal implants of intended treatment areas.
4. History of acne conglobata.
5. Concomitant use of antibiotics in the tetracycline class or oral or topical retinoids (permitted with 14-day washout period).
6. Concomitant use of biologic medications (6-month washout period).
7. Concomitant use of other topical treatments of HS in intended treatment locations (14-day washout period), except for topical benzoyl peroxide or topical clindamycin gel or lotion.
8. History of melanoma.
9. Active skin cancer in the proposed treatment area (non-melanoma in the past 6 month).
10. Current Nd:YAG laser hair removal for HS treatment in the study area.