Successful Treatment of Acne
Erbium:YAG Laser: A Comparative Study
Hend D. Gamil, MD, Elsayed M. Khater, MD, Fathia M. Khattab, MD,
and Mona A. Khalil, MSc.
Dermatology Department, Faculty of Medicine,
Zagazig University, Egypt
Hend D. Gamil MD, Professor of Dermatology, Venereology and Andrology, Faculty
of Medicine, Zagazig University, Egypt
Elsayed M. Khater, MD, lecturer of Dermatology, Venereology and Andrology,
Faculty of Medicine, Zagazig University,
Fathia M. Khattab, lecturer of
Dermatology, Venereology and Andrology,
Faculty of Medicine, Zagazig University, Egypt
Assistant lecturer of Dermatology, Venereology and Andrology, Faculty of
Medicine, Zagazig University, Egypt
words count: 2862
head: Laser Therapy of Acne Keloidalis Nuchae
keloidalis, Er:YAG laser, Nd:YAG laser
keloidalis nuchae (AKN) is a chronic inflammatory disease involving hair
follicles of the neck. It is a form of keloidal scarring alopecia that is often
refractory to medical or surgical management. Laser therapy is a minimally
invasive approach that has shown positive results as an alternative to
conventional therapies in AKN.
Objective: To evaluate the efficacy of Er:YAG
laser in the treatment of AKN as compared to long pulsed Nd:YAG laser.
study was conducted on 30 male patients with AKN. Their ages ranged from 19 to
47 years with a mean age of 36.87 ± 7.8 years. Patients were divided randomly
into two groups of 15 patients, each receiving six sessions of either Er:YAG or
long-pulsed Nd:YAG laser therapy. The clinical response to laser therapy was
evaluated by determining the number, size, consistency and height of plaques
along with the number of papules.
statistically significant decrease in the number of papules was detected at the
end of therapy in both groups, with a mean of 91.8% improvement in the
Er:YAG group versus 88%
Nd:YAG group. A
significant decrease in plaques size and consistency was recorded in both
groups, however, a significant decrease in plaques count was detected only in
Conclusion: The Er:YAG laser proved to be a
potentially effective and safe modality both in the early and late AKN lesions.
Its results are comparable to those of
Nd:YAG laser and its ablative role is effective in advanced lesions.
keloidalis nuchae (AKN), also known as folliculitis keloidalis nuchae, is a
chronic inflammatory condition involving the hair follicles on the nape of the
neck and occupt. This disease occurs most frequently in individuals of African
descent between the ages of 14 and 25; however, a few female patients have also
The initial process begins as acute perifollicular inflammation followed
by weakening of the follicular wall at the level of the lower infundibulum, the
isthmus, or both, the naked hair shaft is then released into the surrounding
dermis, which acts as a foreign body and incites further acute and chronic
granulomatous inflammation(2). Subsequently, fibroblasts deposit new collagen and fibrosis ensues.
Distortion and occlusion of the follicular lumen by the fibrosis results in
retention of the hair shaft in the inferior aspect of the follicle, thereby
leading to the granulomatous
inflammation and scarring(3).
Although the pathogenesis of AKN
remains unclear, proposed etiologies include androgens
,genetics , inflammation, infection, trauma, and in growing hairs. Reasons for localization of AKN to the nuchal and occipital areas remain
unclear. This may be because of an increase in mast cells and dermal papillary
dilatation in the area or friction from scalp skin folds in the occipital
region and possibly obesity. It had suggested that AKN might be a cutaneous
manifestation of the metabolic syndrome(4).
of AKN is difficult, and numerous modalities have been used with varying
degrees of success.Early, mild papular disease may respond to potent or superpotent
topical steroids with or without the use of
retinoid,intralesional triamcinolone acetonide injection can be helpful.
Cryotherapy has also proven to be successful as monotherapy . Surgical excision with primary closure and excision with grafting, the
disease is often refractory to therapy with reported recurrence(5).
ultraviolet B radiation was also found to be useful in improving the appearance
of fibrotic papules. The treatment was well tolerated, and there was some
improvement after 16 weeks of therapy. It was however not as effective as the
removal causes coagulation necrosis of the viable hair follicles and fragmented
hair shafts present in the deep dermis.
Treatment with 1064 nm Nd: YAG and the 810 nm diode lasers have been found
useful in reducing lesion count and size in patients with AKN(7). The 1064 nm
Nd: YAG destroys the hair follicles within the lesions which has some bearing
on the inflammation. Excision by carbon dioxide laser has also been reported to
improve lesions of AKN(8). Laser-assisted hair removal, which
causes coagulation necrosis of the viable hair follicles and fragmented hair
shafts present in the deep dermis, was expected to improve scarring in AKN once
the growing hairs are
removed from the inflammation site(9).
To evaluate the efficacy of Er:YAG
laser in the treatment of AKN as compared to long pulsed Nd:YAG laser.
This single-blinded comparative
clinical study was conducted on thirty patients clinically diagnosed with AKN.
The study was approved by the Institutional Review Board, Faculty of Medicine,
Zagazig University. Each patient signed an informed written consent then was
subjected to history taking, clinical assessment, photography and laser
therapy. Patients were randomly assigned
into two groups of 15 patients each. One group was subjected to erbium: YAG
laser therapy and the other group to long-pulsed Nd:YAG laser therapy for six sessions (four weeks apart).
Clinical assessment of AKN
lesions was done for each patient at baseline and on the 3rd and 6th
laser session and also 3 months after the last session, for clinical response
and side effects. The clinical assessment included papule and plaque counting,
and determination of keloidal plaque sizes by measuring the width and length
then calculation and recording of surface area in cm². Other parameters as the
plaques consistency (firm or soft), height (thick or thin) and degree of
erythema were determined using a scale of 0-3. The global response to treatment
using a quartile grading scale that gauged the percentage of improvement in the
count of papules and the size of plaques where; 0, no improvement (<25%), 1, mild improvement (25%-50%), 2, moderate improvement (51%-75%) and 3, marked improvement (>75%). Side effects of therapy and changes in hair density were
recorded. Photographic documentation was done for
each patient at baseline and at each session using same camera settings.
Topical anesthetic cream was
applied to lesions one hour before laser therapy. Lesions were photo-documented
for all patients at baseline. Fifteen AKN patients were subjected to laser
therapy using the 2940 nm pulsed Er:YAG laser (Fotona – Skinlight Plus surgical
laser system, model 272A). Ablation therapy was performed using a 3 mm spot
size, pulse duration 300 ?s with a frequency of 5 Hz and an energy/ pulse 800 – 980 mJ in partially overlapping mode.
Fifteen patients were subjected
to therapy using the 1064 nm long-pulsed Nd:YAG laser (Synchro-FT laser system,
DEKA, Italy). The lesions were treated using a 13- mm spot size, pulse duration
35 msec. with a fluence of 30-35 J/cm² (adjusted to skin type), in partially
overlapping mode. Pre-cooling of the lesions for 3-5 seconds was performed by
integrated contact cooling using the smart cooler handpiece. After each laser
session, ice compresses were immediately applied to the treated areas for 5- 10
minutes. Topical cream of fusidic acid and betamethasone was applied following
each session for 3 days.
Data analysis was done using a statistical
package for social science (SPSS) version 18. Results were expressed as
frequencies, relative percentages and mean ± SD. Tests used were Chi square
test (c²) and independent T
test. The threshold of significance is fixed at 5% level (P value).
This study included 30 male AKN
patients with skin photo-type III-V, and their ages ranged from 19- 47 years
(mean ± SD, 36.87 ± 7.8).Their disease duration ranged from 0.5 -8 years (mean
± SD, 3.37 ± 2.36). No significant difference was detected between the two
groups with regard to age, duration of lesions, skin type or previous therapy.
No significant difference was detected at
baseline between the two groups with regard to the number of patients with
papules and mean number of papules. In the Er:YAG group, six patients (40%)
presented with papular lesions only and nine patients (60%) presented with both
papular and plaque lesions. In the Nd:YAG group, ten patients (66.6%) presented
with papular lesions, three patients (20%) presented with both papular and
plaque lesions and two patients (13.3%) presented with plaques only.
After laser therapy, there was a
significant decrease in the mean papule count in both groups (P < 0.001 & 0.005 respectively). In Er:YAG group the mean papule count decreased from 18 ± 4.33 at baseline to 4± 1.58 at end of therapy, with a mean of 91% improvement. While in the Nd:YAG group it decreased from 26.69 ± 22.32 to 7 ± 5.09, with a mean of 88% improvement (Table 1,5). Plaque count and size: In the Er:YAG group, a total count of 15 plaques were detected at baseline in nine patients (60%), that significantly decreased after therapy to a total count of 3 plaques in 3 patients (20%). This significant decrease in the mean plaque count was detected both at the 3rd and 6th session (P =0.03 and 0.27 respectively). In the Nd:YAG group, a total count of 8 plaques were detected at baseline in five patients (30%), that non-significantly decreased after therapy to a total of 2 plaques in 2 patients (13.3%) (Table 2, Table 5,Figures 1). A significant reduction in the mean plaque size was detected in both groups after therapy (P = 0.03 & 0.01 respectively). In Er:YAG group the mean plaque size decreased from 2.7 ± 0.86 at baseline to 1± 0 at end of therapy, with a mean of 93% improvement. While in the Nd:YAG group it decreased from 3.33 ± 0.96 to 1.5 ± 0, with a mean of 90% improvement (Table 2). The grading of improvement in the papules count and the plaque size at the final evaluation is shown in figures 2 and 3. There was a significant softening of keloidal plaques at the 3rd and 6th session versus baseline in both groups (P = 0.02 and 0.006 respectively). Also there was a non-significant decrease in the plaque heights in both groups after therapy, while a significant reduction in erythema score was recorded in both groups (P < 0.01 and 0.001 respectively) (Table 4 ) Crustation was observed after Nd:YAG laser therapy in 2 patients (13.3%) that was cleared within one week. No other side effects were observed in both groups. Hair density was decreased in both groups, however it was more significantly decreased in the Nd:YAG group versus Er:YAG group (80% versus 40%, P= 0.02). No recurrence of lesions was observed after 3 months follow-up period in both groups. DISCUSSION This study was aimed to evaluate the efficacy of Er:YAG laser in the treatment of AKN as compared to long pulsed Nd:YAG laser in the treatment of AKN.A total of thirty patients with clinically proven AKN were enrolled in this study. Patients were randomly divided into two groups of 15 patients for therapy with each laser. Nd:YAG laser therapy One group of 15 patients was subjected to long-pulsed Nd:YAG laser therapy. Their ages ranged from 19 to 45 years with a mean age of 33.07± 8.61 years. Ten patients (66.6%) presented with only papular lesions, three patients (20%) presented with both papular and plaque lesions, and two patients (13.3%) presented with plaques only, with a total of eight plaques. There was a statistically significant decrease in the number of papules in the Nd:YAG group at both the 3rd and 6th laser sessions (p=0.04 and 0.005, respectively), with a mean improvement of 88% at the end of therapy. Additionally, a decrease in the number of plaques was recorded at the end of therapy; however, this decrease was not statistically significant. There was a statistically significant decrease in plaque size at the third and sixth sessions (p=0.02 and 0.01, respectively). Plaque size decreased from 3.33±0.96 to 1.5±0, with a mean improvement of 90% at the end of therapy. Our results are consistent with those reported by Attia et al.,(10) where 91% reduction in papule count and 70% reduction in plaque size using Nd:YAG laser. Our results were consistent with those reported by Esmat et al.,(5) where 16 patients with AKN were treated with a long-pulsed Nd:YAG laser for five sessions, each a month apart. The authors detected a significant decrease in the papule count in all patients at the third and fifth laser sessions, with a mean improvement of 82% at the end of therapy. Additionally, the authors reported a significant decrease in plaque count at the third and fifth sessions along with a reduction in plaque size, with a mean improvement of 84% at the end of therapy. Unlike the Esmat et al. study(5) where a significant decrease was seen in plaque height, we did not observe any change in plaque height after therapy. Authors from the Esmat et. al. study also detected a significant softening of keloidal plaques which is consistent with our results. In our study, improvement was evaluated based on the reduction in the number of papules and the size of plaques after the laser sessions. Five patients (38.5%) showed moderate improvement in the papule count, and eight patients (61.5%) showed marked improvement. With regard to the reduction in the plaque size, 12.5% plaques showed mild improvement, 12.5% plaques showed moderate improvement, and 75% plaques showed marked improvement. Authors from the Esmat et al.(5) study found that improvement in the early cases (75%) was statistically higher than improvement in the late cases (25%). No such difference was observed in our study, where the percentage of improvement in the early cases was 61.5% and that for late cases was 75%. Abu-Samra et al.(11) treated nine AKN patients with skin type V-VI by 1064 nm long-pulsed Nd:YAG laser for 3-6 sessions one week apart. They reported good improvement in six patients with a significant reduction in the number of papules and pustules without hypo-pigmentation and in three patients with moderate reduction in the number of papules and pustules. A highly significant reduction in the erythema score was observed in this study at the third and sixth sessions compared with the baseline score (p= 0.002 and < 0.001, respectively), and this was consistent with the results of Esmat et al.(5) who reported a significant reduction in the erythema score at the third and fifth sessions in all patients compared with the baseline score. Regarding side effects, post laser crust was reported in only two patients (13.3%), who were treated with antibiotic cream and were cured within one week. No pigmentary changes were observed, but there was a significant reduction in the hair density reported at the sixth session in 12 patients (80%) compared with that at baseline, and this reduction was accepted by all patients. Esmat et al.(5) reported post laser crust formation in six patients (37.5%), which was completely cured within two weeks. There was also a significant reduction in hair density at the third and fifth sessions compared with baseline. By the end of our study, nine patients (60%) were very satisfied and six patients (40%) were satisfied in group A. All (100%) completed the 3-month follow-up period, and no recurrence was observed, as the re-growing hairs were thinner and unable to re-penetrate the skin. Re-growth of hair that was thinner, softer and less dense than the original hair was observed three months after the sixth session. Attia et al.(10) also observed no recurrences in the 3-month follow-up period. Esmat et al.(5) reported a few papular lesions in two (20%) of the ten patients (63%) that completed the one-year follow-up period. There was also no recurrence of lesions at the 15-month follow-up period in a patient with AKN treated using the long-pulsed Nd:YAG laser(12). Schulze et al.(6) used different types of lasers in the treatment of PFB, which shares a similar hair-related pathogenesis with AKN. The different lasers used were long-pulsed alexandrite laser, Q-switched Nd:YAG laser and low-fluence 1064 nm Nd:YAG laser; all lasers were effective to some degree. Er:YAG laser therapy The second group in our study included 15 patients subjected to 2940 nm Er:YAG laser ablative therapy, with a spot size of 3 mm, partially overlapping mode, a frequency of 5 Hz, an energy/pulse between 800 and 980 mj, a duration of 60 sec and a pilot beam level of 7 for six sessions. Six patients (40%) presented with only papular lesions and nine patients (60%) presented with both papular and plaque lesions with a total of 15 plaques. The duration of the lesions ranged from 1 year to 10 years, with a mean duration of 4.60 ± 2.84 years. We reported a highly significant decrease in the papule count in all patients at the third and sixth laser sessions (p<0.001 and 0.001 respectively) with a mean improvement of 91.8% at the end of therapy. Additionally, there was a significant reduction in the plaque count at the third and sixth session (p=0.04 and 0.03, respectively) and a significant reduction in the plaque size at the third and sixth session (p=0.04 and 0.03, respectively), with a mean improvement of 93% at the end of therapy. Two patients (13.3%) showed a moderate response and 13 patients (86.7%) showed an excellent response in papule count reduction. In late cases, four plaques (26.7%) showed moderate improvement, and 11 plaques (73.3%) showed marked improvement. When comparing the graded improvement in the early (86.7%) and late (73.3%) cases in the Er:YAG group, there was no statistically significant difference. When comparing the graded improvement between the two groups, there was also no statistically significant difference. Thus, the erbium:YAG laser is as effective as the long-pulsed Nd:YAG laser in the treatment of both papular and keloidal lesions of AKN. We also reported a significant softening of the plaques at the end of therapy. The decrease in height was, however, not statistically significant. Notably, the erythema score was significantly reduced at the final evaluation. No significant side effects were reported except for a transient reduction in hair density at the sixth session in only 6 patients (40%). There was a significant difference in the hair density between the groups, with 80% reduction in the Nd:YAG group and 40% reduction in the Er:YAG group. This can be explained by the mechanism of action of the Nd:YAG laser that specifically targets and destroys hair follicles. At the end of our study, eight patients (53.3%) were very satisfied and seven patients (46.7%) were satisfied in the Er:YAG group. All of them completed the 3-month follow-up period, with no recurrence. Wagner et al.(13) used a 2940 nm erbium:YAG laser with a fluence of 3-4 J/ cm2 and 5-mm spots to treat 21 patients with keloids and hypertrophic scars for six sessions. They observed a significant reduction in the redness (51.3%), hardness (48.9%) and scar elevation (50.0%) with no significant side effects. This is consistent with our results of significant softening, decrease in height and erythema score of the keloidal plaques with no side effects. CONCLUSION Although several modalities of treatment are available for the management of AKN, no single modality is fully effective, especially in advanced cases. This study indicates that laser hair epilation can be an effective, minimally invasive and safe modality for the treatment of AKN. At least six sessions are required to obtain a satisfactory response. Reduction of the hair density in the treated area is the only side effect observed. Additionally, the Er:YAG laser proved to be an effective and safe modality in both early and late lesions of AKN. Its results are comparable to those of the Nd:YAG laser, and it has a faster recovery and fewer side effects. Although the pathological mechanism is not clearly understood, the ablative role of this treatment is effective in treating advanced AKN lesions. Larger randomized studies with a long-term follow up are recommended to establish its exact role and mechanism of action in AKN. REFERENCES 1. Lindsey SF, Tosti A. Ethnic hair disorders. Curr. Probl. Dermatol. 2015;47:139-49 2. Ogunbiyi A, Adedokun B. Perceived aetiological factors of folliculitis keloidalis nuchae (acne keloidalis) and treatment options among Nigerian men. Br. J. Dermatol. 2015 Jul;173 Suppl 2:22-5. 3. Shapero J, Shapero H. Acne keloidalis nuchae is scar and keloid formation secondary to mechanically induced folliculitis. 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