Hidradenitis is a chronic disease of the apocrine glands (a form of sweat gland found on certain parts of the body). For unknown reasons, people with hidradenitis suppurativa develop plugging or clogging of their apocrine glands. It causes chronic scarring and pus formation of the underarms (axilla) and groin/inner thigh areas. In women it can also occur under the breasts. It is similar to acne, which is also a disease of the sebaceous glands. Hidradenitis is more common in people who have had acne. It may be an unusual type of adult acne.

Hidradenitis suppurativa is slightly more common in women and African-Americans. Hidradenitis usually starts as one or more red, tender, swellings in the groin or armpits. Over a period of hours to days the lesions enlarge and often open to the skin surface draining clear to yellow fluid. The involved area then heals with scarring. The condition usually continues for years with periods of flare and remission.

See hidradenitis suppurativa pictures

Available medical treatments for hidradenitis suppurativa, including systemic antibiotics, retinoids and biologics, have limited efficacy and significant side effects. Although surgery can be effective, it is associated with significant morbidity, including risks of infection and permanent scarring.

The long-pulsed 1,064 nm Nd:YAG laser provides safe and effective treatment for hidradenitis suppurativa, according to a study conducted by dermatologists Bassel H. Mahmoud, M.D., Ph.D.; Emily Tierney, M.D.; Camile Hexsel, M.D.; David Ozog, M.D.; and Iltefat Hamzavi, M.D., of the Henry Ford Medical Center, Detroit. The study group enrolled 22 patients (skin types II-VI) with Hurley stage II / III hidradenitis suppurativa that was bilateral and symmetric in distribution. Treatment sites included the axilla, inframammary region and/or groin.  Areas of involvement on one side of the body were treated with topical antibiotics only, and the contralateral side was treated with topical antibiotics and the Nd:YAG laser. A total of four laser treatments were performed at monthly intervals and patients were followed for an additional two months thereafter.

Study results

  • At the six-month visit, the mean modified LASI score for all laser-treated sites combined was reduced significantly from baseline, and was significantly lower compared with the mean score for the control sites.
  • The laser treatment was associated with pain in 40 percent of patients, but didn’t interfere with their daily activities. There were no significant adverse events related to its use.
  • Patient satisfaction with the treatment was favorable and exceeded levels of satisfaction with previous medical therapy.
  • Although multiple lasers are available for performing photoepilation, the 1,064 nm wavelength of the Nd:YAG laser makes it a rational choice for treating hidradenitis suppurativa thanks to its ability to penetrate to the site of disease involvement in the deeper dermis; in addition, and due to the fact that the 1064 nm wavelength is relatively less absorbed by melanin, it is safer for use in darker skin types.

Mechanism of action

The investigators speculate that the mechanism of action for the treatment benefit involves laser-induced hair removal and a photothermolysis effect leading to ablation and destruction of inflammatory lesions in the reticular dermis. These hypotheses are supported by findings from clinical evaluations and histopathologic studies.

Patients reported an early reduction in pain accompanied by an increase in discharge, which suggests the laser treatment worked similarly to surgical incision and drainage, ablating the hair follicle and allowing the discharge to escape through the follicular unit. “Our histopathology studies showed an early inflammatory reaction around the hair follicle, and evidence of follicular destruction at one month post-treatment,” Dr. Mahmoud says.

Differential responses

The differential responses of the three anatomic sites treated — the axillae, inframammary region and groin — are also consistent with the concept that hair removal is a primary mechanism of action.

Although improvement occurred at all three sites, when comparing the percentage changes from baseline LASI score, there was a statistically significant benefit for the combination treatment with the laser compared to the control only for the axillae and groin.

“Hairs in the groin and axillae are darker, terminal coarse hairs that respond better to photoepilation treatment than do the finer, vellus type hairs located in the inframammary region,” Dr. Mahmoud says.


This study is another example of the expanding diversity of treatments that can be performed with the 1064 nm wavelength.