Use of the pulsed infrared diode laser (904 nm) in the treatment of
MAKRAM WAIZ1, ANMAR Z. SALEH2, RAAFA HAYANI1& SAMAR O. JUBORY1
1Department of Dermatology and Venereology, Baghdad Teaching Hospital, Baghdad, Iraq, and2Department of Medical
Physics, College of Medicine, University of Baghdad, Baghdad, Iraq
Background. Alopecia areata is a rapid and complete loss of hair in one or several patches, usually on the scalp, affecting both
males and females equally. It is thought to be an autoimmune disease which is treated with different modalities with variable
success. Laser treatment of different wavelengths has been used in the management of this problem.
Objective. To study the effect of the pulsed infrared diode laser (904 nm) in the treatment of alopecia areata.
Methods. Sixteen patients with 34 resistant patches that had not responded to different treatment modalities for alopecia
areata were enrolled in this study. In patients with multiple patches, one patch was left as a control for comparison. Patients
were treated on a four-session basis, once a week, with a pulsed diode laser (904 nm) at a pulse rate of 40/s. A photograph
was taken of each patient before and after treatment.
Results. The treated patients were 11 males (68.75%) and five females (31.25%). Their ages ranged between 4 and 50 years
with a mean of 26.6¡SD of ¡13.8, and the durations of their disease were between 12 months and 6 years with a mean of
13.43¡SD of ¡18.34. Regrowth of hair was observed in 32 patches (94%), while only two patches (6%) failed to show any
response. No regrowth of hair was observed in the control patches. The regrowth of hair appeared as terminal hair with its
original color in 29 patches (90.6%), while three patches (9.4%) appeared as a white villous hair. In patients who showed
response, the response was detected as early as 1 week after the first session in 24 patches (75%), while eight patients (25%)
started to show response from the second session.
Conclusion. The pulsed infrared diode laser is an effective mode of therapy with a high success rate for resistant patches of
Key words: Alopecia areata, laser
Alopecia areata (AA) is a common a symptomatic
skin disease characterized by a rapid onset of non-
scarring hair loss in a sharply defined area. Any hair-
bearing surface may be affected, especially the scalp
(1). It affects 1% of the population and can occur at
any age, most commonly in children. Although it is
not life-threatening, the hair loss can be psycholo-
gically harmful (2,3).
The cause of AA is thought to be mainly
attributed to an autoimmune process, which may
be modified by genetic factors and aggravated by
emotional stress (1). Many studies have documented
an abnormal cell-mediated immune reaction in AA.
There is an increased suppressor T-cell function in
patients experiencing hair regrowth. Antibodies to
pigmented hair follicles were detected by Western
blotting in the sera of 100% of the AA patients
examined compared with only 44% of normal
The treatment of AA depends on the severity and
extent of the disease. These include a topical irritant,
and topical and intralesional steroids in mild cases.
However, more aggressive therapy is used for severe
cases such as systemic corticosteroids, immunosup-
pressive drugs and immune modulators (1).
The laser (light amplification by stimulated emis-
sion of radiation) has been used in the treatment of
different skin diseases. The laser beam differs from
the ordinary light by being coherent, monochromatic
and polarized. It concentrates its beam in a defined
position. These properties allow low-energy laser
light to penetrate the surface without damage of the
Correspondence: Professor Makram Al-Waiz, Department of Dermatology and Venereology, College of Medicine, University of Baghdad, PO Box 61269,
Medical Collection Post Office, Postal Code 12114, Bab Almua’dham, Baghdad, Iraq. E-mail: email@example.com
(Received 17 November 2005; accepted 18 January 2006)
Journal of Cosmetic and Laser Therapy. 2006; 8: 27–30
ISSN 1476-4172 print/ISSN 1476-4180 online # 2006 Taylor & Francis
Low-level lasers are generally smaller, less expen-
sive and operate in the milliwatt (mW) range, 1–
500 nW. The therapy performed with such lasers is
often called low-level laser therapy (LLLT) or just
‘laser therapy’ and the lasers are called ‘therapeutic
lasers’. Several other names have been given to these
lasers, such as the ‘soft laser’ and ‘low-intensity level
laser’, whereas the therapy has been referred to as
‘biostimulation’ and ‘biomodulation’. The latter
term is more appropriate, since the therapy cannot
only stimulate, but also suppress biological processes
.No side effects were recorded from the biostimula-
tive light energy directed to the body cells (8).
LLLT offers improved possibilities in the treat-
ment of pain, wound healing, inflammation and
oedema (8). LLLT has been used to treat patches of
AA with variable success rates (9).
This study was designed to evaluate the effect of
pulse infrared diode laser in the treatment of AA.
Materials and methods
This study included 34 resistant patches (which had
not responded to different modalities of treatment)
from 16 patients suffering from AA (scalp514,
eyebrow5six, beard512, moustache5two) attend-
Venereology at Baghdad Teaching Hospital in the
period between March 2004 and August 2004. The
diagnosis of AA was performed clinically. All
patients were thoroughly assessed in relevance to
their condition. In patients with multiple patches,
one patch was left as a control for comparison.
Photographs were taken for each patient before and
after the treatment.
Laser apparatus was a patented dental unit
invented by Mario Scalvini, researcher of the
Italian National Research Council, in 1989.
The laser used to treat the patches was a low-level
invisible pulsed infrared diode laser (904 nm)
wavelength, with a peak power of 150 W.
The treatment technique was carried out by
multiple application of the laser in a series of circles
in close contact with each other toward the center
until the total area of the patch was treated.
However, the overall treatment may not give an
exact coverage of the total area because the applica-
tion is prone to human error. The probe is 3 mm in
diameter and treats the same area at each application
(area50.07065 cm2), which takes about 5 seconds,
from the pulsed laser of 40 pulses per second. The
probe was in contact with the skin of the treated
area. Patients were advised not to use any other
treatment modality during the 1-month long laser
therapy (four sessions, once weekly). All patients
were assessed every week for hair regrowth and for
any adverse effects such as itching, erythema and
scaling. The final regrowth was categorized into two
groups: first, those patches with complete hair
growth with terminal hair; second, those patches
with partial hair growth with villous hair.
The follow-up period was to 2 months after the
last session. Calculation of the average power was
carried out as follows:
where PM5average power during the treatment
time, owing to pauses between pulses; so the average
power will be in the region of mW
P5is the peak power (in W)
t5the time in which the laser radiation is actually
T5the interval between one pulse and the other.
If P5150 W, t 5200 ns, T52561023, then the
average energy is:
The treated patients were 11 males (68.75%) and
five were females (31.25%). Their ages ranged
between 4 and 50 years with a mean of 26.6¡SD
of ¡13.8, and the duration of their diseases were
between 12 months and 6 years with a mean of
13.43¡SD of ¡18.34. In the treated patches (total
of 34), regrowth of hair was observed in 32 patches
(94%) while only two patches (6%) failed to show
any response (Table I).
The regrowth of the hair appeared as terminal hair
with its original color in 29 patches (90.6%), while
three patches (9.4%) appeared as a white villous hair.
In patients who showed response, the response
was detected as early as 1 week after the first session
in 24 patches (75%), while eight patients (25%)
started to show response from the second session
Those patches (seven) that were left without
treatment (as controls) showed no regrowth of hair
at the end of treatment sessions performed to other
patches on the same patients. They were eventually
treated in the same manner.
During the treatment sessions no adverse effects
were noticed. Also, between and after the sessions,
patients did not complain of any side and unwanted
The follow-up period showed no fall of hair in
those patches that responded to treatment.
AA is a non-scaring hair loss. Most authors tend to
classify AA as an autoimmune disease (10). There
are many modes of therapy including both topical
M. Waiz et al.
mechanisms such as irritants, sensitizers, immuno-
modulators, and others (1,3,11).
The variable and uncertain natural history of AA
accounts for the multiplicity of uncritical claims for a
large variety of therapeutic procedures. However, it
is fortunate that a variety of choices of therapy are
available and all these work in favor through its
High-powered laser, mainly used for medical
treatment, causes tissues to break after it is absorbed
and turned into thermal energy. However, low-
powered laser generates only a small amount of
energy, of which a direct irradiation induces a slight
somatic temperature change ranging between 0.1˚C
and 0.5˚C. While high-powered laser is an expensive
system that can raise output power up to 100 W,
low-powered laser is a relatively low-priced system
that only has a few milliwatts (12).
The biological effects of low-powered laser are
widely reported, including anti-inflammation, pain
reduction, wound healing, anti-edema, antibiosis,
immunity and local blood circulation improvement
Gundogan and his group reported two cases of AA
showing homogenous and thick regrowth of hair
after 11–12 treatment sessions with the 308 xenon
chloride excimer laser and explained this as a result
of the immunosuppressive action of the excimer
laser which may induce T-cell apoptosis (14).
In this work, the treatment of AA with laser gave a
very successful result and, importantly, most of the
treated patients had previous unsuccessful, conven-
tional, treatments for alopecia, some of them for
more than 2 years, including treatment with
irritants, corticosteroids, immunosuppressive drugs
and PUVA for severe cases.
The laser used is pulsed, which gives high local
energy but with less heating to the vicinity of the
treatment. This means it can give effective energy
and may cause local heating by giving high energy
for a period during a pulse which, in turn, does not
between the pulses so there is no heat build-up,
but it can influence the molecules which play an
important role in clearing the disease.
The wavelength of laser used for treatment is of
prime importance for producing an effect on a
specific molecule. Researchers assumed that even
though they did not know how low-powered laser
increased hair follicles and tensile strength, it was
agreed that one or more factors among improved
micro-vascular circulation, reduced inflammation
and increased cell energy in the form of ATP
(adenosine triphosphatase) worked together (13).
Alopecia is considered to be an autoimmune
disease, which means the immune system does not
recognize ‘self’ from a non-self antigen. Discussion
in the field of immunity is far too complex and
beyond the scope of this work, but we ought to
explain some possibilities that may be related to
autoimmunity and the laser treatment of alopecia. It
has been reported that one cause of the autoimmune
disease is a hidden antigen which may be exposed to
the self immune system, causing an immune reaction
which may influence the hair follicles, including
inflammation and a consequent effect on the blood
supply in the capillaries (15). Some modification of
the cell membrane caused by drugs or some kind of
disease could make the cells unrecognized by the
immune system as self (15).
Having known all the above factors, the cause of
low-energy laser action on the disease is still unclear;
however, the laser may alter either the cellular
membrane or change the previously exposed ‘hidden
antigen’ which may become hidden again.
In conclusion, the low-pulsed diode laser can be
considered a promising mode of therapy in resistant
patches of AA.
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Table I. Details of alopecia areata patches and their response to treatment.
Results of treatment
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(4 after 1 week)
(8 after 1 week)
(2 after 1 week)
Treatment of AA with the pulsed infrared diode laser
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