Microneedling: Advances and widening horizons

Loading...

Taking too long?

Reload document

| Open in new tab

[Downloaded free from http://www.idoj.in on Thursday, October 11, 2018, IP: 106.223.45.98]

Department of
Dermatology and
Venereology, AIIMS,
New Delhi, India

ABSTRACT

Review Article

Microneedling: Advances and widening
horizons

Aashim Singh, Savita Yadav

Microneedling is a very simple, safe, effective, and minimally invasive therapeutic technique. It was initially
introduced for skin rejuvenation, however, now it is being used for a very wide range of indications including
acne scar, acne, post‑traumatic/burn scar, alopecia, skin rejuvenation, drug delivery, hyperhidrosis, stretch
marks, and many more. Moreover, during the last 10 years, many new innovations have been made to the
initial instrument, which was used for microneedling. This technique can be combined with other surgical
techniques to provide better results. In particular, it is a very safe technique for dark skin types, where risk of
postinflammatory pigmentation is very high with other techniques that damage the epidermis. In this review
article, we are updating on the different instruments now available for this procedure, and its efficacy when
performed alone or in combination with other techniques for various indications.

Key words: Dermaroller, dermatosurgery, microneedling, percutaneous collagen induction

INTRODUCTION

Microneedling is a relatively new minimally
invasive procedure involving superficial and
controlled puncturing of the skin by rolling with
miniature fine needles. Over a short period
of time, it has gained mass popularity and
acceptance as it is a simple, cheap, safe, and
effective technique requiring minimal training.
Traditionally used as a collagen induction therapy
for facial scars and skin rejuvenation, it is also
widely used now as a transdermal delivery
system for therapeutic drugs and vaccines. In
this review, we highlight the constantly evolving
research and developments in microneedling
techniques, instruments, and its applications in
dermatology.

THE INVENTION

The advent of the concept of microneedling
dates back to 1995 when Orentreich and
Orentreich described dermal needling in the
form of subcision for scar treatment and then
independently in 1997 by a plastic surgeon
Camirand who used tattoo guns without ink
to take-off tension from postsurgical scars.[1,2]
Microneedling technique was given further shape
by a German inventor Liebl in 2000 and a plastic

surgeon Fernandes in 2006 who self-designed a
drum-shaped device with multiple fine protruding
needles and used it for percutaneous collagen
induction.[3,4]

BASIC INSTRUMENT

The standard medical dermaroller [Figure 1]
has a 12 cm long handle with a 2 × 2 cm wide
drum-shaped cylinder at one end studded
with 8 rows and 24 circular arrays of 192 fine
microneedles, usually 0.5–3 mm in length and
0.1–0.25 mm in diameter.[3] These single use
microneedles are synthesized by reactive ion
etching techniques on silicon or medical-grade
stainless steel. The instrument is presterilized
by gamma irradiation. Rolling with a standard
dermaroller containing 192 needles of 2 mm
length and 0.07 mm diameter over an area of
skin for 15 times results in approximately 250

This is an open access article distributed under the terms of the
Creative Commons Attribution-NonCommercial-ShareAlike 3.0
License, which allows others to remix, tweak, and build upon
the work non-commercially, as long as the author is credited
and the new creations are licensed under the identical terms.

For reprints contact: reprints@medknow.com

Cite this article as: Singh A, Yadav S. Microneedling:
Advances and widening horizons. Indian Dermatol Online J
2016;7:244-54.

© 2016 Indian Dermatology Online Journal | Published by Wolters Kluwer – Medknow

Access this article online

Website: www.idoj.in

DOI: 10.4103/2229-5178.185468

Quick Response Code:

Address for
correspondence:
Dr. Savita Yadav,
Department of
Dermatology and
Venereology, AIIMS,
New Delhi, India.
E‑mail: savita2081@
gmail.com

244

[Downloaded free from http://www.idoj.in on Thursday, October 11, 2018, IP: 106.223.45.98]

the release of various proteins, potassium, and growth factors
from the cells into the exterior leading to the migration of
fibroblasts to the site of injury, and hence, collagen induction.
Thus, the needles do not create a wound in a real sense, but
rather body cells are fooled into believing that the injury has
occurred.[9,11-13]

The expression of matrix metalloproteinases induced
b y m i c r o n e e d l i n g i s s p e c u l a t e d i n r e d u c t i o n o f
hyperpigmentation.[11] In addition, the hyperproliferation of
keratinocytes is downregulated by microneedling in acne
patients because it overall balances out the cell equilibrium.[11]
However, more research needs to be done to elucidate the
chain of events clearly.

Microneedling enhances the delivery of various drugs across
the skin barrier as it bypasses the stratum corneum and
deposits the drug directly up to the vascularized dermis. It has
also been shown to cause significant widening of the follicular
infundibulum by 47%, which may partly explain the increased
penetration of the medication across the skin barrier. In addition,
it removes the scales and sebum residues in the neighbourhood
of the infundibulum.[14]

Hence, this procedure extrapolates the body’s own physiology
of wound healing and the new collagen deposition results in
skin tightening and filling-up of atrophic scars with an overall
better aesthetic appeal since overlying epidermis is not
ablated.

PROCEDURE

Microneedling is a simple office-based procedure lasting
10 to 20 minutes depending on the area to be treated.
The patients must be counselled prior to the procedure
explaining the expected outcomes, delayed response, and
need for multiple sittings. The skin should preferably be
prepared preoperatively for at least a month with vitamin A
and C formulations twice a day to maximize dermal collagen
formation. Vitamin A influences 400–1000 genes that control
proliferation and differentiation of all major cells in epidermis
and dermis, and Vitamin C is essential for production of
normal collagen.[10]

The procedure is performed under topical anesthesia
containing eutectic mixture of lignocaine and prilocaine/
tetracaine for 45 minutes to 1 hour. After preparation of the
area with antiseptic and saline, the skin is stretched with
one hand, and perpendicularly, rolling is done 5 times each
in the horizontal, vertical, and oblique directions with the
other hand [Figure 2]. The treatment endpoint is identified
as uniform pin-point bleeding which is easily controllable.
Post-procedure, the area is made wet with saline, or ice

a

b

c

Figure 1: Different variety of Dermarollers: (a) Dermaroller with narrow
width of drum meant for smaller areas such as eyelids and nose; (b)
Dermaroller with 540 needles; (c) Standard dermaroller with 192 needles

holes per square cm upto the papillary dermis depending on
the pressure applied.[5] Each pass produces 16 micropunctures
in the stratum corneum per square cm without damaging the
epidermis significantly.[6]

Principle and mechanism of action
Micropunctures are created using microneedles which produce
a controlled skin injury without actually damaging the epidermis.
These microinjuries lead to minimal superficial bleeding and
set up a wound healing cascade with release of various
growth factors such as platelet derived growth factor (PGF),
transforming growth factor alpha and beta (TGF-α and TGF-β),
connective tissue activating protein, connective tissue growth
factor, and fibroblast growth factor (FGF).[7] The needles
also breakdown the old hardened scar strands and allow it
to revascularize. Neovascularization and neocollagenesis is
initiated by migration and proliferation of fibroblasts and laying
down of intercellular matrix.[8,9] A fibronectin matrix forms after
5 days of injury that determines the deposition of collagen
resulting in skin tightening persisting for 5–7 years in the form
of collagen III. The depth of neocollagenesis has been found
to be 5–600 µm with a 1.5 mm length needle. Histological
examination of the skin treated with 4 microneedling sessions
1 month apart shows upto 400% increase in collagen
and elastin deposition at 6 months postoperatively, with
a thickened stratum spinosum and normal rete ridges at
1 year postoperatively.[10] Collagen fibre bundles appear to
have a normal lattice pattern rather than parallel bundles as
in scar tissue.[6]

Liebl et al. have proposed another hypothesis to explain how
microneedling works.[11] Resting electrical membrane potential
of cells is approximately −70 mV, and when needles come
near the membrane, the inner electrical potential increases
quickly to −100 mV. This triggers increased cell activity and

Indian Dermatology Online Journal – July-August 2016 – Volume 7 – Issue 4

245

Singh and Yadav: New in microneedling [Downloaded free from http://www.idoj.in on Thursday, October 11, 2018, IP: 106.223.45.98]

The minimum time interval between two sittings of microneedling
depends upon the indication for which the procedure is being
done as well as the needle length of the dermaroller being
used. More is the needle length, greater should be the interval
between two sittings of microneedling. When using 1.5 mm
dermaroller, at least 3 weeks gap should be there between
two procedures.

Five basic types of medical dermarollers, which are registered
with the FDA, have been described in the dermaroller series
by Konstantinos, and most dermarolling devices are adopted
from these elementary types:[16]
• C-8 (Cosmetic type), is the basic dermaroller as described
above with a needle length of only 0.13 mm (130 µm) used
for enhancing penetration of topical agents. It is completely
painless.

• C-8HE (Cosmetic type for hair-bearing surfaces, scalp)
has a needle length of 0.2 mm (200 µm). Even this length
is below the pain threshold.

• CIT-8 (CIT: Collagen Induction Therapy, Medical type) has
a needle length of 0.5 mm (500 µm) and helps in collagen
induction and skin remodelling.

• MF-8 type has a needle length of 1.5 mm (1500 µm). This
creates deeper microchannels on the whole epidermis
and dermis and at the same time destroys scar collagen
bundles.

• MS-4 is the only dermaroller that has a smaller cylinder,
1 cm length, 2 cm diameter, and subsequently 4 circular
arrays of needles (total 96 needles) that have 1.5 mm
length. It is used on areas where better precision and
deeper penetration is required. It is mostly used on facial
acne scars.

• Devices similar to MS-4 are available with needle lengths of
0.5–0.75 mm, which are used for thin-skinned areas such
as the periorbital and perioral regions.

Home care dermaroller
Home-care dermarollers (C-8) are used by patients
themselves as they are of needle length less than 0.15 mm
and are available for reduction of pore size, fine lines, and
sebum production, as well as for transdermal delivery of
substances such as lipopeptides and other antiageing
products. They can be used twice or thrice a week for up
to 100 times. After use, the rollers should be cleaned in
hot tap water and shaken dry.[3,17] Beauty Mouse is another
approved device intended for home use. It contains a total
of 480 needles of approximately 0.2 mm size on 3 separate
drums strategically placed inside a computer mouse shaped
device. It has been developed to ensure coverage of larger
skin surface areas, such as the arms, legs, and buttocks
for the treatment of stomach or thigh stretch marks and
cellulite.[18]

Figure 2: Pin-point bleeding over the cheek following microneedling
procedure

packs can be used for comforting the patient. Thereafter,
the patient is advised to use sunscreen regularly and follow
sun-protective measures. The procedure is well-tolerated by
the patients and there are usually no post-treatment sequelae
except slight erythema and edema lasting for 2–3 days.
There is no downtime and the patient can resume daily work
the very next day. Treatments are performed at 3–8 week
intervals and multiple sittings are needed to achieve the
desired effect on the skin. The final results cannot be viewed
immediately because new collagen continues to be laid
down for approximately 3–6 months after treatment has
ceased.[10,15]

V A R I O U S I N S T R U M E N T S A N D
TECHNIQUES

A simple dermaroller has evolved over the past decade through
a variety of advancements. The current market is booming with
an assortment of devices based on needle length, drum size,
and automation [Figure 1].

The most important is the diversity of needle lengths. High ratio
of tip length versus diameter of 13:1 is an important property of
good needles.[6] The length of needle selected for an individual
patient depends upon the indication for microneedling. For
treating acne and other scars as a routine, a needle length of
1.5–2 mm is usually used. When microneedling is used as a
procedure to treat ageing skin and wrinkles, the needle length
of 0.5 mm or 1.0 mm is usually recommended.[9] When the
needles are only up to 0.5 mm long, the procedure is essentially
painless, and the perception of pain increases as the depth of
needle penetration increases. It also depends on the thickness
of epidermis and dermis of the skin.

246

Indian Dermatology Online Journal – July-August 2016 – Volume 7 – Issue 4

Singh and Yadav: New in microneedling [Downloaded free from http://www.idoj.in on Thursday, October 11, 2018, IP: 106.223.45.98]

Derma‑stamp
These are miniature versions of the dermaroller available
in different needle lengths (0.2–3 mm) and a diameter of
0.12 mm that are used for localized scars such as varicella
scars. Advantage over the dermaroller is that a more focussed
treatment of individual scars is possible. It causes vertical
penetration to create infusion channels in the skin and is
considered ideal for use on isolated scars and wrinkles.[3,5,17,18]

Dermapen
Dermapen [Figure 3] is an automated microneedling device
which looks like a pen. This ergonomic device makes use of
disposable needles and guides to adjust needle length for
fractional mechanical resurfacing. The tip has 9–12 needles
arranged in rows. It makes use of a rechargeable battery to
operate in two modes, namely, the high speed mode (700 cycles/
min) and the low speed mode (412 cycles/min) in a vibrating
stamp-like manner.[19] It has the advantage of being reusable
in different patients as the needles are disposable, safe as the
needle tips are hidden inside the guide, and more convenient to
treat narrow areas such as the nose, around the eyes and lips
without damaging the adjoining skin. It makes the procedure
less painful and more economical as there is no need to buy
a new instrument every time.[20] This technology has been
designed to overcome the issues of varying pressure application
and the subsequent depth of penetration achieved.[18]

DermaFrac
DermaFrac treatment is a newer modification of microneedling
combining microdermabrasion, microneedling, simultaneous
deep tissue serum infusion, and light emitting diode (LED)
therapy. DermaFrac treatments target aging and sun damaged
skin, acne, enlarged pores, uneven skin tone, wrinkles,

fine lines, hyperpigmentation, and superficial scars. It takes
approximately 45 min to complete full face treatment when
all four modalities are used. This noninvasive, cost-effective
treatment carries the advantage of having no downtime with
individualized selection of serums for infusion.[20,21]

Microneedle delivery systems
Microneedle delivery systems offer a minimally invasive and
painless method of transdermal drug administration, especially
useful for vaccines.[22] The various types of microneedles
available for this purpose can be solid, coated, dissolving,
hollow, and swellable polymer microneedles synthesized by
microfabrication technique.[18] Silicon, metals such as titanium,
natural and synthetic polymers, and polysaccharides are
the various materials used to fabricate these microneedles.
Solid-coated microneedles are used to pierce the superficial
skin followed by topical application and delivery of the drug,
whereas dissolvable or biodegradable and hollow needles
deliver drugs directly into the dermis.[22]

Fractional radiofrequency microneedling
The amalgamation of microneedling with radiofrequency has
further expanded the prospects of application of this technology.
Insulated needles are used to penetrate the skin and release
radiofrequency currents from the needle tips producing thermal
zones in the dermal structural components and accessory
glands without damaging the overlying epidermis.[23] This
triggers long-term dermal remodelling, neoelastogenesis, and
neocollagenesis. The depth of the needles can be adjusted
from 0.5 mm to 3.5 mm allowing us to target different layers of
the dermis discretely.[24] Operating person can exercise a good
control over tissue damage by adjusting the power level and
duration of energy pulse. The main energy delivery system has
a disposable tip with 49 gold plated needles. Microneedling
radiofrequency (MNRF) technology does not damage the
epidermis, and is therefore, safe in darker skin types. Its
indications include scar treatment, hyperhidrosis, skin
tightening, rejuvenation, and many more.

Light emitting microneedling device
LED microneedling rollers have been recently launched.
These incorporate titanium microneedles and LED light to
combat wrinkles and scarring.[19] These devices have not yet
been explored and no published data is available regarding
its efficacy.

APPLICATIONS OF MICRONEEDLING IN
DERMATOLOGY

Dermarolling has been used for a wide range of indications
with many trials supporting evidence for its usefulness.[5,6,17,23]
It has been tried alone as well as in combination with other
treatment modalities such as chemical peeling, platelet rich

247

Figure 3: Dermapen with battery charger

Indian Dermatology Online Journal – July-August 2016 – Volume 7 – Issue 4

Singh and Yadav: New in microneedling [Downloaded free from http://www.idoj.in on Thursday, October 11, 2018, IP: 106.223.45.98]

plasma, radiofrequency, subcision, punch elevation, and lasers.
It is often used in conjunction with a topical formulation, and
hence, enhances its penetration and action.

Nonacne scars
Post-burn scar, post-traumatic scar, hypertrophic scars,
varicella scars [Table 3].

Skin rejuvenation
Microneedling leads to reorganization of old collagen fibres and
laying down of new collagen, elastin, and capillaries leading
to the effect of skin tightening. A significant increase in level
of collagen type I, III, and VII, newly synthesized collagen and
tropoelastin from baseline was observed after 6 microneedling
sessions at 2-week intervals by El-Domyati et al.[25] This
percutaneous collagen induction leads to an overall youthful
appearance of the skin by reducing fine lines and wrinkles,
reducing pore size, more suppleness, and elasticity.

The effects are enhanced when the procedure is combined with
topical antiageing vitamin C serum and tretinoin application.
Microneedling has also been combined with human embryonic
stem cells derived endothelial precursor cell conditioned
medium and has shown significant reduction in wrinkles and
pigmentation.[26,29] Fractional microneedling radiofrequency has
been studied in a large multicentre trial and has found to be
effective in reducing wrinkles [Table 1].[27]

Scars
Acne scars
The most frequently used indication of microneedling is
post-acne facial atrophic scars [Figure 4], and a large number
of trials have been conducted to evaluate the same alone
as well as in combination with chemical peels, platelet-rich
plasma, subcision, cryotherapy, and CROSS technique.
Microneedling has been found to be more effective for rolling
and boxcar scars, and relatively less effective in ice-pick
scars. It is safe for all skin types with minimal downtime.
Only the affected area needs to be treated and there is
minimal risk of post-inflammatory dyschromia. However,
a minimum of 4–6 sessions are required for a significant
improvement [Table 2].

Post-surgical scars were the first to be studied by Camirand[2]
who used tattoo gun needles to reduce the scars. Since then,
microneedling has been used for almost all types of surgical
scars and are to be found useful. Microneedling has been
found to be effective in reducing even burn scars [Figure 5]
by up to 80% in a study on 16 patients by Aust et al. It was
stipulated that there is normalization of collagen-elastin matrix
in the dermis at 1 year.[10,15] Microneedling is also effective for
varicella scars [Figure 6] and post-traumatic scars [Figure 7].

Acne vulgaris
The advent of fractional microneedling radiofrequency has
expanded the application of microneedling to acne vulgaris
as well. It directly targets the sebaceous glands and helps in
reducing the sebum production. It is also known to reduce the
hyperproliferation of keratinocytes [Table 4].

Androgenic alopecia and alopecia areata
Use of microneedling over scalp for alopecia is one of its recent
advances. It has been compared with minoxidil alone and
has been found to be better in combination.[47,48] Home-use
dermarollers are prescribed to patients who are using minoxidil,
and a better hair growth is observed. However, when topical
minoxidil was compared with Platelet Rich Plasma (PRP) and
microneedling therapy in a recent study, minoxidil alone continued
to remain better.[49] Microneedling has also been combined with
topical triamcinolone acetonide application in alopecia areata
and better response has been observed [Table 5].[50]

P i g m e n t a t i o n — M e l a s m a a n d p e r i o r b i t a l
hypermelanosis
The introduction of Dermafrac technique and smaller drums
with needles sizes approximately 0.5 mm has made the
microneedling to periocular skin amenable. Microneedling

Table 1: Microneedling trials for skin rejuvenation (literature search after year 2010)

Author

No. of patients

Objective

Outcome

Clementoni et al.[28]

Year

2010

2013

2014

21

15

25

10

Calderhead et al.[27]

2013

499

Seo et al.[29]

Lee et al.[26]

248

El-Domyati et al.[25]

2015

Photodynamic photorejuvenation of the
face with a combination of microneedling,
1 hour ALA incubation followed by red
light and broadband-pulsed light

90% of patients judged clinical
improvement to be greater than 50%
at 6 months compared to baseline
photography

Multicentre study to evaluate efficacy of
microneedling fractional radiofrequency

Comparison of FMRF with and without
stem cell medium

80-89% overall improvement, 30-36%
decrease in wrinkle size, 25-29% decrease
in wrinkle depth after 2-3 sessions

Combination found to be better

To study efficacy of microneedling with
human stem cell conditioned medium

Combination better than microneedling
alone (P<0.05) To study objective and histological efficacy of microneedling Increased collagen I, III, VII, and tropoelastin (P<0.05) Indian Dermatology Online Journal - July-August 2016 - Volume 7 - Issue 4 Singh and Yadav: New in microneedling [Downloaded free from http://www.idoj.in on Thursday, October 11, 2018, IP: 106.223.45.98] a b c a c e a c b d f b d Figure 4: Pre (a, c, e) and post (b, d, f) treatment photographs of post-acne atrophic scar patients after 4 sittings of microneedling done 1 month apart Figure 5: Post-burn scar on the thigh of 1 year duration treated with a combination of microneedling and laser (a) Baseline photograph; (b). Scar showing improvement after 3 fortnightly sessions of microneedling; (c) Further improvement in scar following 1 session of Fraxel laser RE: STORE SR 1500nm (Solta Medical, USA) with following parameters: 70 mj beam energy, 20% density, 8 passes. (Courtesy: Dr Arshdeep, Consultant Dermatologist, Kubba Skin Clinic, New Delhi) Figure 7: Significant improvement in post-traumatic scar over the nose after 1 sitting of subcision followed by 3 sittings of microneedling done 1 month apart Figure 6: Post-varicella scars (a,c) showing improvement (b,d) after 3 microneedling sittings done 1 month apart has been combined with various skin lightening agents and chemical peels to reduce melasma as well as periorbital hypermelanosis [Table 6]. Miscellaneous conditions Extended applications of microneedling include stretch marks, axillary hyperhidrosis, and actinic keratosis in photodamaged skin. MNRF has been used even in patients with rosacea and post-acne erythema with favorable results [Table 7]. Indian Dermatology Online Journal - July-August 2016 - Volume 7 - Issue 4 249 Singh and Yadav: New in microneedling [Downloaded free from http://www.idoj.in on Thursday, October 11, 2018, IP: 106.223.45.98] Table 2: Studies using miconeedling for facial post acne atrophic scars (literature search after year 2010) Year No. of patients Objective Outcome Comparison of microneedling with and without glycolic acid peels Combination found to be better To study efficacy in atrophic facial acne scars Mean improvement of 50-75% from baseline Microneedling with PRP vs Microneedling with vitamin C Evaluation of Microneedling Fractional Radiofrequency Device Comparison of subcision with dermaroller vs. subcision with cryoroller To analyze efficacy in different skin phototypes PRP combination found better (P=0.01) Improvement-58% moderate and 29% minimal Adverse effects-mild erythema, postinflammatory hyperpigmentation, track marks of the device Cryorolling better than microneedling Significant reduction in scars (P<0.05) in all phototypes without dyspigmentation in any, 31% reduction in skin irregularity Comparison of microneedling with and without subcision 100% efficacy with combination, 77% with microneedling alone To assess objective and histological efficacy Improvement seen, increased collagen (P<0.05) To assess efficacy of microneedling alone Mean 80% improvement Comparison of microneedling with TCA CROSS Comparable results Comparison of Nonablative Fractional Erbium Laser 1340 nm and Microneedling Comparable results Author Sharad[30] Dogra et al.[31] Chawla et al.[32] 2011 2014 2014 Chandrashekar et al.[24] 2014 Gadkari et al.[33] 2014 Fabbrocini et al.[34] 2014 Hassan[35] El-Domyati et. al.[36] Pandey et al.[37] Puri[38] Cachafeiro et al.[39] 2015 2015 2015 2015 2016 60 36 30 31 30 60 70 10 30 30 46 Year 2010 2010 2011 2014 Table 3: Microneedling for non‑acne scar treatment (literature search after year 2010) Indication Author No. of patients Objective Outcome Burn scars Burn scars Kim et al.[40] Aust et al.[15] Burn scars Sofanov[41] Varicella scars Costa et al.[42] 25 16 1 1 To study the effectiveness of Dermastamp Improvement seen (P<0.05) To study efficacy of microneedling in reducing post-burn scars without damaging epidermis 80% improvement in scarring, 45% thickened stratum spinosum, normal rete ridges after 1 year Assessment of efficacy Good improvement Significant improvement Table 4: Fractional microneedling radiofrequency trials for acne vulgaris (literature search after year 2010) Indication Acne vulgaris Acne vulgaris Acne vulgaris Author Lee et al.[43] Lee et al.[44] Kim et al.[45] Year 2012 2013 2014 Acne and acne scars Min et al.[46] 2015 No. of patients Objective Outcome 18 20 25 20 To assess the efficacy of FMRF Reduced number of lesions To assess the efficacy of FMRF 70-80% reduced sebum Treatment of acne vulgaris with FMRF Comparison of FMRF with bipolar radiofrequency 76% reduction in acne, 37% reduction in sebum (P<0.05) Superior efficacy of FMRF Table 5: Microneedling trials for alopecia (literature search after year 2010) Indication Author No. of patients Objective Androgenic alopecia Dhurat et al.[47] Alopecia areata Chandrashekar et al.[50] 2014 Androgenic alopecia Dhurat et al.[48] Patterned hair loss Farid et al.[49] Year 2013 2015 2016 100 2 4 40 Comparison of topical minoxidil with and without microneedling To study the efficacy of microneedling with topical triamcinolone acetonide Outcome Combination better (P=0.039) Response seen To study efficacy in patients not responding to minoxidil and finasteride Up to 75% improvement Comparison of PRP microneedling with topical 5% minoxidil Minoxidil remains better 250 Indian Dermatology Online Journal - July-August 2016 - Volume 7 - Issue 4 Singh and Yadav: New in microneedling [Downloaded free from http://www.idoj.in on Thursday, October 11, 2018, IP: 106.223.45.98] Table 6: Microneedling trials for pigmentation (melasma and periorbital hypermelanosis) (literature search after year 2010) Indication Author Year No. of patients Objective Outcome Sahni et al.[20] 2013 To study the efficacy of Dermafrac 75-90% improvement Comparison of combined skin needling with depigmenting serum and depigmenting serum alone Reduction in MASI score more on combination side compared to serum alone (P<0.001) Melasma Fabbrocini et al.[51] 2011 Periorbital hypermelanosis Melasma Budamakuntla et al.[52] Melasma Lima[53] Periorbital hypermelanosis Markantoni et al.[54] Periorbital hypermelanosis Kontochistopoulos et al.[55] 2013 2015 2015 2016 20 1 60 22 13 13 Comparison of tranexamic acid microinjections against tranexamic acid with microneedling 44.41% reduction in MASI score in microneedling group compared to 35.72% reduction with microinjections To evaluate efficacy in recalcitrant cases Improvement seen Combination of microneedling and 10% TCA peels Combination of microneedling and 10% TCA peels Improvement in 92.3% patients Improvement seen Table 7: Microneedling trials for miscellaneous indications (literature search after year 2010) Indication Author Year No. of patients Objective Outcome Actinic keratosis Bencini et al.[56] 2012 83% showed complete response Torezan et al.[57] 2013 Acinic keratosis and photodamage Primary axillary hyperhidrosis Striae rubra Sanad et al.[59] 2015 Rosacea Park et al.[60] 2015 Kim et al.[58] 2013 To study efficacy of FMRF 12 10 20 30 To study efficacy of microneedling with topical PDT Comparison of PDT with and without microneedling Comparison of microneedling with and without trichloroacetic acid peeling To study efficacy of microneedling fractional radiofrequency FMRF in post inflammatory acne erythema Combination better (P=0.004) Reduced number and size of sweat glands Combination better (P<0.05) 25-58% improvement Post-acne erythema Min et al.[61] 2015 25 Improvement seen (P<0.05) Skin laxity a. Lax skin on arms, abdomen, neck, thighs, areas between breast and buttocks[5,6,17] b. To tighten skin after liposuction. TRANSDERMAL DELIVERY OF DRUGS The technique of microneedling has been well-exploited to increase penetration of drugs across the skin barrier. This has been proven in in‑vitro skin models where enhanced absorption of larger molecules such as calcein has been observed.[62,63] Microneedles cover a range of activity between that of a t