Utilization of Nd:YAG Laser (1064 nm) in the treatment of dermatosis

Dermatologia Kliniczna 2009, 11 (4): 197-201
ISSN 1730-7201
PRACE ORYGINALNE / Original articles
Copyright © 2009 Cornetis; www.cornetis.com.pl
Utilization of Nd:YAG Laser (1064 nm) in the treatment of dermatosis papulosa nigra
in some Sudanese patients
Zastosowanie lasera Nd:YAG (1064 nm) w leczeniu dermatosis papulosa nigra u pacjentów z Sudanu
Shaza Mohammed Yousif, Nafie A. Al-Muslet, Nagi Zarif Malati
Institute of Laser – Sudan University of Science and Technology, Khartoum/Algerian, Republic of Sudan
Address for correspondence:
Nafie A. Al-Muslet
Institute of Laser – Sudan University of Science and Technology
the west campus – P.O. Box (407)
Khartoum / Algerian, Republic of Sudan; tel.: 00249183765635, e-mail: mnmfa2008@yahoo.com
Introduction: Skin of phototypes IV to VI according to Fitzpatrick represents the majority of the world’s population. Clinically, the features of photoaging in African
can include fine wrinkling, mottled pigmentation, and dermatosis papulosa nigra (DPN). All studies have confirmed the effectiveness and low risk of complication
associated with use of Nd: YAG laser in dark skin patients.
Objectives: This study aimed to detect the effectiveness of Nd: YAG laser, 1064 nm, with specific laser parameters, in the treatment of dermatosis papulosa nigra
(DPN) in some Sudanese patients.
Material and methods: Twenty patients, clinically diagnosed as cases of dermatosis papulosa nigra, were selected from different dermatology clinics in Khartoum
state and were considered as study population. Nd: YAG laser, with 1064 nm wavelength, was used in this study. The laser parameters were: non-contact applications
of bare fiber, power of 25 Watt and duty cycle of 0.2 second. The number of exposure intervals delivered per lesion was chosen according to the size of papules.
The data was analyzed using SPSS 15.0, and p-value of p<0.05 had been used.
Results: Relationship of the treatment response and Northern tribes was found statistically relevant (p<0.05). Three and six weeks after the last session, evaluation
of patients response was as following: • Excellent response in 17 patients (85%), • Very good in 3 patients (15%), • Good (0.0%), • Bad (0.0%), • No response (0.0%).
Conclusions: This study proved that the use of Nd: YAG laser 1064 nm, with certain parameters could achieve excellent or very good results in all patients.
Key words: Nd:YAG laser, dermatology, laser therapy, dermatosis papulosa nigra
Abstract
Streszczenie Wprowadzenie: Większość ludzi na świecie ma skórę o fototypie od IV do VI wg klasyfikacji Fitzpatricka. Klinicznie, do cech starzenia się skóry wynikającego z pro-
cesów zależnych od promieniowania słonecznego (photoaging) w Afryce, należy zaliczyć: drobne zmarszczki, plamiste pigmentacje oraz dermatosis papulosa nigra
(DPN). Liczne badania potwierdziły skuteczność i bezpieczeństwo zabiegów wykonywanych przy użyciu lasera Nd:YAG u czarnoskórych pacjentów.
Cel badań: Ocena skuteczności zabiegów wykonywanych przy użyciu lasera Nd:YAG (1064 nm) w leczeniu dermatosis papulosa nigra u pacjentów z Sudanu.
Materiał i metody: Do badań włączono 20 pacjentów z kilku klinik z prowincji Khartoum, u których rozpoznano dermatosis papulosa nigra. Zabiegi wykonywano
laserem Nd:YAG, emitującym promieniowanie o długości fali 1064 nm o następujących parametrach: końcówka bezkontaktowa, moc 25 Watt, długość impulsu 0.2 s.
Liczba przerw podczas zabiegów zależała od wielkości usuwanej zmiany. Wyniki były analizowane za pomocy oprogramowania SPSS 15.0, przyjęto p-value dla
p<0.05.
Wyniki: Wykazano statystycznie istotny związek w odpowiedzi na leczenie jedynie u pacjentów pochodzących z plemion północnego Sudanu (p-value<0.05). Trzy
lub sześć tygodni po ostatniej sesji laseroterapii oceniono skuteczność leczenia na: • Wspaniała odpowiedź u 17 pacjentów (85%), • Bardzo dobra u 3 pacjentów (15%),
• Dobra (0.0%), • Zła (0.0%), • Bez odpowiedzi (0.0%).
Wnioski: Przeprowadzone badanie wykazało, że w leczeniu dermatosis papulosa nigra zabiegi przy użyciu lasera Nd:YAG (1064 nm) były bardzo skuteczną metodą
terapeutyczną u wszystkich pacjentów.
Słowa kluczowe: laser Nd:YAG, dermatologia, terapia laserowa, dermatosis papulosa nigra
Introduction
Clinically, the features of photoaging in African can include:
fine wrinkling, mottled pigmentation, and dermatosis papulosa
nigra (DPN).
DPN is a multiple, small, hyper pigmented, flattened, or
verrucous asymptomatic papules that measure 1-5 mm in
diameter, common among blacks (1). It is a benign cutaneous
condition, classified within the group of epithelial nevi and by
some authors, considered as small seborrhoeic keratoses (2, 3).
DPN can be graded (G) as follows (4):
• GI (mild) – less than 10 spots,
• GII (moderate) – 10 to 50 spots,
• GIII (severe) – more than 50 spots.
The small elevations of the skin of DPN can sometimes
develop thicker scaling but, crusting, and ulceration do not
occur (4, 5). The pathophysiology of DPN is not known. It is likely
to be genetically determined, with 40-54% of patients having
a family history of involvement. It is believed to be caused by
a nevoid developmental defect of the pilosebaceous follicle
(6). Histopathology shows the appearance of a seborrhoeic
keratosis, they display hyperkeratosis, irregular acanthosis,
keratin-filled invaginations of the epidermis (horn cysts), and
marked hyperpigmentation of the basal layer. Although most
lesions are of the acanthotic type and show thick interwoven
tracts of epidermal cells, they may have a reticulated pattern
in which the tracts consist of a double row of basaloid cells
(2, 6).
197
Yousif S.M., Al-Muslet N.A., Malati N.Z.
Utilization of Nd:YAG Laser (1064 nm) in the treatment of dermatosis papulosa nigra in some Sudanese patients
The incidence of DPN, as well as the number and size of
individual lesions, increases with age. It usually begins in ado­
lescence and is rare under the age of 7 years. Data pertaining
to the international frequency of DPN are insufficient. It affects
up to 35% of the African American population. Blacks with a fair
complexion have the lowest frequency of involvement. Females
are affected more frequently than males (2, 5).
The applied removal methods of lesions are: freezing (cryo­
surgery), scraping (curettage), burning (electrocautery) and
laser treatment (4). Locally destructive treatment can result
in complications, which include increased and decreased
pigmentation, scarring and keloid formation. Nd:YAG laser has
recently been reported to achieve excellent cosmetic results
with minimum complication. Even though other lasers have
been used successfully, like 532 nm diode-pumped laser, carbon
dioxide (ultra pulse) laser, 585 nm pulsed dye laser and Nd:YAG
Q-switched laser (5).
Objectives
This study aimed
A. To detect the effectiveness of Nd:YAG laser, 1064 nm, with
specific parameters, in the treatment of dermatosis papulosa
nigra in some Sudanese patients.
B. To determine the possible association between the ef­fec­
tive­ness of Nd:YAG laser in the treatment of dermatosis papulosa
nigra and demographic data.
Material and methods
Patients
Twenty patients, clinically diagnosed as cases of dermatosis
papulosa nigra, were selected for this study from different
dermatology clinics in Khartoum state and were considered as
study population.
Selected patients were:
• Over 18 years of age.
• Able to give informed consent.
• Desire removal of lesions.
• Willing to come back for one week, three and six weeks
follow-up.
• Willing to fill out post operative questionnaire.
• With at least 4 lesions less than 7 mm.
• Diagnosis of DPN.
EMLA cream was used one hour pre-operatively as topical
anesthesia at site of lesion. Elovera sun block lotion SPF 30 was
used post-operatively as topical sun screen.
The patients included in the study were photographed
before the treatment, and at intervals of one week and three
weeks after the last session.
All patients were requested to participate voluntarily, and
a written informed consent was done with ethical clearance
from patient himself, before being enrolled in the study. They
were informed about the possible side effects and the hazards
of laser therapy. Confidentiality of the patients was maintained
For each patient, a confidential record of personal data was
made. This includes: serial number, date of operation, name, age,
sex, tribe, occupation, address as well as detailed information
about the medical history of the patient, morphology, site,
duration and classification of the lesion. The details are listed in
table I.
Patients grouping
Patients were classified in three groups according to the
number of lesions: Group I; less than 10 spots, Group II; 10 to 50
198 spots and GIII; more than 50 spots.
Dermatologia Kliniczna 2009, 11 (4)
The laser medical system
Nd:YAG laser (neodymium-yttrium-aluminum-garnet), model
Fibertom 5100, with 1064 nm wavelength, manufactured by
Dornier MedTech (Germany), was used in this study. Nd:YAG
laser parameters used were: non-contact applications of bare
fiber, power of 25 Watt, and exposure interval (duty cycle)
of 0.2 second. The number of exposure intervals delivered
per lesion was chosen according to the size of papules. The
function of the Nd-YAG laser in this study was to coagulate the
melanin and concerned blood vessels in the lesions. It emits
wavelength of 1064 nm which penetrates to 1600 µm and is
well absorbed by melanin and blood. The absorbed laser power
is converted into heat, causing coagulation of the targeted
vessels.
Nd:YAG laser procedures
All patients were sharing the standard mode, single pulse,
with exposure interval (duty cycle) of 0.2 second, power of
25 Watt, power density of 3125 Watt/cm2, and spot size of
0.008 cm2. But they differ in the exposure time and number
of sessions regarding the irradiated areas.
Lasing procedure
The hand of the fiber was held close to the lesion in non
contact mode.
The lasing switch was turned on. The foot switch was pressed
repeatedly and different numbers of exposure intervals were
applied point by point on the lesion and then (popcorn like)
sound was heard or blanching of color was seen. Sessions were
done on one week intervals.
Postoperative care
Sun block lotion was prescribed for daily use when exposed
to sun light. After the last session, one week and three
weeks follow up appointments were given to the patient to
evaluate the results. A post-operative photo was taken from
the site of the lesion at one week and three weeks after the last
session.
Evaluation of the results
For the evaluation of the treatment response, 10% was
given for the response of the treatment for every element
of evaluation. Ten elements of evaluation are considered
below. Excellent response achieved when no element for
evaluation was developed, very good response achieved
when the percentage of elements for evaluation was ≤20%,
good response achieved when the percentage was ≤40%,
poor response achieved when the percentage was ≤60% and
bad response achieved when the percentage of elements for
evaluation was >60%.
Elements for evaluation of the treatment response:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Prolonged erythematic lasting more than 24 hours.
Purpura lasts >14 days.
Hypopigmentation lasts >3 weeks.
Atrophic or hypertrophic scaring.
Keloid formation.
Postoperative blistering.
Delayed wound healing.
Wound infection.
Residual tissue.
Patients satisfaction <70%.
Data analysis
The data was entered in spread sheets and analyzed using
SPSS 15.0 and p-value of p < 0.05 had been used.
Yousif S.M., Al-Muslet N.A., Malati N.Z.
Zastosowanie lasera Nd:YAG (1064 nm) w leczeniu dermatosis papulosa nigra u pacjentów z Sudanu
Results and discussion
Table I: Background data of patients
Tabela I: Dane opisujące pacjentów
Sex
Płeć
Age group (Year)
Grupa wiekowa (wiek w latach)
Tribe
Plemię (pochodzenie)
Family history of similar condition
Występowanie rodzinne
Consanguinity
Stopień pokrewieństwa
Background data of patients
Dane opisujące pacjentów
Female / Kobiety
Man / Mężczyźni
Total / Łącznie
18-40
41-60
>60
Total / Łącznie
N / z północy
E / ze wschodu
W / z zachodu
S / ze wschodu
Total / Łącznie
Positive / Tak
Negative / Nie
Total / Łącznie
First degree / I stopnia
Second degree / II stopnia
Non / Żadne
Total / Łącznie
18 (90%)
2 (10%)
20 (100%)
12 (60 %)
8 (40 %)
0 (0%)
20 (100%)
16 (80%)
2 (10%)
2 (10%)
0 (%)
20 (100%)
20 (100%)
0 (0%)
20 (100%)
4 (20%)
6 (30%)
10 (50%)
20 (100%)
Clinical data of the patients
For all patients, the morphology of the lesions, site, duration
and classification are illustrated in table II.
Table II. Clinical data of the patients
Tab. II. Dane kliniczne
Duration of lesions
(Year)/Czas od wystąpienia zmian (w latach)
Morphology
Morfologia zmian
Site of lesion
Umiejscowienie zmian
Classification
Klasyfikacja
Response of DPN to Nd:YAG laser
Clinical data of the patients
Dane kliniczne
Longest / Najdłuższy
Shortest / Najkrótszy
Mean duration / Średni czas
Papule / Grudki
Papule & verrucae / Grudki i powierzchnie brodawkujące
Total / Łącznie
Face / Twarz
Face & neck / Twarz i szyja
Face, neck, upper chest & back / Twarz, szyja, górna część tułowia i plecy
Total / Łącznie
Grade I / Stopień I
Grade II / Stopień II
Grade III / Stopień III
Total / Łącznie
The response was achieved in all patients, after one, two
or three sessions. Relationship of the treatment response
and Northern tribes was found with (p value <0.05), no
other relationship between treatment response and other
demographic data was found. Three and six weeks after the last
session, evaluation of patients was:
• Excellent response in 17 patients (85%)
• Very good response in 3 patients (15%)
• Good response (0.0%)
• Bad response (0.0%)
20
1
1.35
16 (80%)
4 (20%)
20 (100%)
9 (45%)
9 (45%)
2 (10%)
20 (100%)
1 (5%)
9 (45%)
10 (50%)
20 (100%)
• Poor response (0.0%)
• No response (0.0%)
Almost all patients experienced transient erythematic not
more than 24 hours. Fifteen patients (75.0%) developed transient
hypopigmentation which faded out within three weeks after
treatment. Eight patients (40.0%) developed hyperpigmentation,
in only half of them (four patients) the hyperpigmentation
resolved at six weeks. In literature, hyperpigmentation is almost
always transient and fades out from three to four months (7, 8).
The figures 1-3 show a comparison for some cases before,
and three weeks after laser treatment.
199
Yousif S.M., Al-Muslet N.A., Malati N.Z.
Utilization of Nd:YAG Laser (1064 nm) in the treatment of dermatosis papulosa nigra in some Sudanese patients
200
Fig. 1a. Before laser treatment
Ryc. 1a. Przed laseroterapią
Fig. 1b. Three weeks after treatment
Ryc. 1b. Trzy tygodnie po laseroterapii
Fig. 2a. Before laser treatment
Ryc. 2a. Przed laseroterapią
Fig. 2b. Three weeks after treatment
Ryc. 2b. Trzy tygodnie po laseroterapii
Fig. 3a. Before laser treatment
Ryc. 3a. Przed laseroterapią
Fig. 3b. Three weeks after treatment
Ryc. 3b. Trzy tygodnie po laseroterapii
Dermatologia Kliniczna 2009, 11 (4)
Yousif S.M., Al-Muslet N.A., Malati N.Z.
Zastosowanie lasera Nd:YAG (1064 nm) w leczeniu dermatosis papulosa nigra u pacjentów z Sudanu
Conclusions
This study proved that the use of Nd:YAG laser is preferable
in treating DPN, because it is easy to perform, the response was
excellent in majority of treated patients (85.0%) and very good
in the rest of them (15.0%) and the complications were minimal
and almost transient. Relationship of the treatment response
and Northern tribes was found statistically relevant (p value
<0.05), which was not found in other demographic data.
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Received: 2009.02.10
Approved: 2009.12.04
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