SAN DIEGO – Pilonidal disease – a chronic inflammatory condition that can trigger the formation of cysts and sinuses in the superior portion of the intragluteal cleft or the sacrococcygeal area – remains challenging to manage, but mounting evidence supports the use of lasers to enhance treatment success.
“Draining sinuses or acute abscesses are usually associated with an underlying cyst and associated granulation tissue, fibrosis, and tufts of hair,” Catherine M. DiGiorgio, MD, said at the annual conference of the American Society for Laser Medicine and Surgery. “This is why laser hair removal can help with the treatment of these patients.”
Dr. Catherine M. DiGiorgio
The suspected etiology is a foreign body reaction to the entrapped hairs, which are found in the sinuses in about 75% of cases. “The treatment for that is surgery,” said Dr. DiGiorgio, a laser and cosmetic dermatologist in Boston. Laser hair reduction decreases the recurrence of cyst formation and drainage, and is usually covered by insurance, she noted.
Supportive evidence
In a comparative study, French researchers retrospectively reviewed the efficacy of laser hair removal after surgery in reducing recurrence rate of pilonidal cysts, versus surgery alone. Of the 41 study participants, 12 had laser hair removal plus surgery and 29 had surgery alone. The rate of cyst recurrence was significantly lower in the laser hair removal plus surgery group, compared with the surgery only group (8.3% vs. 51.7%, respectively; P < .001).
In another study, researchers from the United Kingdom and The Johns Hopkins Hospital, Baltimore, evaluated the use of the long-pulsed Alexandrite laser in 19 patients with recurrent pilonidal disease who had undergone multiple surgeries.They were treated with the laser for hair removal in the sinus area, requiring 4-12 sessions. The researchers found that 84.2% of patients had a reduction of hair density to less than 5 hairs/cm2, while 15.8% had a reduction of hair density to 5-10 hairs/cm2. They also noted a statistically significant increase in disease-free time in the laser-treated group compared with those treated with surgical management only (P < .01).
Lasers for pseudofolliculitis barbae, HS
Lasers also play a significant role in the treatment of pseudofolliculitis barbae, a chronic, inflammatory disease that primarily affects the bearded area of men with thick hairs, usually those with a darker Fitzpatrick skin type. This can also occur in women, particularly those with polycystic ovary syndrome, Dr. DiGiorgio said.
In people with pseudofolliculitis barbae, the hair follicle is positioned at an acute angle to the skin surface and the sharp end of shaved hair reenters the skin, which results in the formation of pustules, papules, secondary infection, and keloids. Treatment involves a variety of medical therapies including retinoids, benzoyl peroxide, antibiotics, and keratolytics, “but laser hair removal is the best way to get rid of this issue, and results in permanent reduction,” she said. “When treating male patients with laser hair removal in the bearded area, you have to tell them that they won’t be able to grow a beard going forward. Most of them are okay with that.”
A 2002 study, led by E. Victor Ross, MD, of the Naval Medical Center, San Diego, evaluated treatment of pseudofolliculitis barbae in patients with skin types IV, V, and VI with a long-pulsed Nd:YAG laser. For the first phase of the study, the investigators tested epidermal tolerance on the thighs of 37 patients and determined that the laser was safe and effective. For the second phase 2 weeks later, they treated a 15x15-mm submental area with the highest fluence tolerated in phase 1 of the trial and used an adjacent site as the control.
After 90 days, the mean papule count was 6.95 for the control site compared with 1 for the laser-treated site. The researchers observed that miniaturization and elimination of hair shafts resulted in decreased inflamed papules. “We know that this works,” Dr. DiGiorgio said.
In another study from investigators at the Naval Medical Center, San Diego, 22 patients with skin types IV, V, and VI who had pseudofolliculitis barbae underwent 5 weekly treatments with a 1,064 nm Nd:YAG laser. Topical anesthesia was not used, and 10 evaluators used a Global Assessment Scale (GAS) to assess treatment success from photos taken at baseline and at 4 weeks. At 4 weeks, 11 patients demonstrated 83% improvement on the GAS (P < .01), the investigators reported.
Laser and energy-based treatments can also be used to treat hidradenitis suppurativa (HS), a chronic condition that affects apocrine gland–bearing skin. “The hypothesized pathogenesis is that it’s an inflammatory disorder of the hair follicle, where the follicle rupture introduces its contents into the surrounding dermis,” Dr. DiGiorgio said. “The skin reacts with a chemotactic response and abscess formation. This results in inflammatory nodules and sterile abscesses, which can lead to sinus tracts and hypertrophic scars and chronic drainage, which can be foul-smelling. This frequently leads to depression and psychological distress for the patients.”
Possible laser and energy-based treatments for HS include follicular destruction with the Nd:YAG laser, the diode laser, the Alexandrite laser, microwave technology, or intense pulsed light, she said. Microwave technology or radiofrequency can be used for sweat gland destruction, while CO2 lasers can be used to debulk tissue, and the ablative fractional CO2 laser can be used to reduce scarring and improve range of motion.
In a prospective, randomized, intraindividual comparative trial conducted at eight centers in France, researchers evaluated the use of a long-pulsed Nd:YAG laser to treat 36 patients with mild to moderate HS; 27 had inguinal disease and 9 had axillary disease. They received four laser treatments at 6-week intervals; laser settings varied depending on the patient skin type.
At 1 month, there was a significant reduction in the number of inflammatory lesions on the areas treated with lasers, compared to the untreated areas, but the difference was not significant at 3 months. There was no significant difference in the number of flares between the treated and untreated sites at 1 or 3 months.
In a separate study, researchers found that the Nd:YAG laser in combination with topical benzoyl peroxide and clindamycin was significantly more effective than topical benzoyl peroxide and clindamycin alone for the treatment of HS in 22 patients with Hurley stage II disease. The patients received monthly treatments for 4 months and were followed up 2 months after the last treatment; the Hidradenitis Suppurativa Area and Severity Index was used to measure treatment response.
Statistically significant improvements were observed in the inguinal and axillary areas but not in the inframammary areas. Most patients (90%) reported less frequent breakouts while 10% reported no change. “In addition, 92% of subjects felt that the use of laser was more effective than other treatments they had tried but 8% stated it was equal to the other treatments they had tried,” said Dr. DiGiorgio, who was not affiliated with the study. “The researchers noted continued improvement with subsequent laser sessions,” she added.
According to 2019 guidelines from the United States and Canadian HS Foundations on the management of HS – in the section on light, laser, and energy sources – an Nd:YAG laser is recommended in patients with Hurley stage II or III disease on the basis of randomized, controlled trials and case series data, and in patients with Hurley stage I disease based on expert consensus. “Other wavelengths that are used for follicular destruction are recommended on the basis of lower-quality evidence,” the recommendations state.
The guidelines also state that CO2 laser excision “is recommended in patients with Hurley stage II or III disease with fibrotic sinus tracts” while “external beam radiation and PDT have a limited role in the management of patients with HS.”
Dr. DiGiorgio reported having no relevant disclosures.