Lasers, lights and acne

Author: Assoc. Prof. Marius Rademaker, Hamilton, New Zealand, 2008.


Most acne patients notice an improvement in their acne over the summer, although unfortunately it doesn’t last long. Ultraviolet light (phototherapy) has long been used in the management of acne, as has superficial radiotherapy. However, the well-established long-term side effects of radiotherapy, and the concerns around the skin cancer risks of ultraviolet light/sun beds, have limited their use.

The last few years however, have seen an increased interest in the use of light and laser therapy for acne. There are two main mechanisms that laser/light treatments may help acne:

  1. By destroying skin bacteria Propionibacterium acnes through a photodynamic therapy (PDT) reaction
  2. By destroying the sebaceous glands / entire pilosebaceous unit

To date, many studies have shown early promise, with improvements in the 50-75% range. However, most of the trials have been fairly small, of short duration and with relatively short follow-up periods. Few have had the opportunity to assess long term outcomes and, very importantly, long term complications/side-effects.

It is difficult to know where lasers/lights will eventually fit in the overall management of acne vulgaris. For some individuals, they are likely to be beneficial, although very few comparative studies have been made with conventional medical treatment.

Lasers/lights that destroy P. acnes through a photodynamic therapy (PDT) reaction

The mechanism of action

It is known that the bacteria present in some acne lesions, P. acnes, produce chemicals called porphyrins during their growth and proliferation in the skin pore (follicular unit). These porphyrins may contribute to how non-inflamed acne lesions become inflamed.

It is thought that the two main porphyrins involved are protoporphyrin IX (PpIX) and coproporphyrin III. Both of these chemicals absorb light at 415nm (the Soret band), which corresponds to the blue range of the visible light spectrum, and to 630nm, which corresponds to red light.

Photo-excitation of these porphyrins, from exposure to an appropriate light source, will form singlet oxygen (free radicals) within the bacteria, which then selectively destroy them, thereby hopefully improving the clinical signs of the acne.

Types of light / laser sources

There are a number of light and lasers being investigated. These include:

  1. Blue and red light sources
  2. Green light lasers
  3. Yellow light lasers
  4. Intense pulsed light (IPL) sources
  5. Radiofrequency (RF) devices

Blue light machines

There are a number of units that produce ‘Blue’ light. These tend to be high-intensity, narrow-band blue light source in the 405nm-420nm range.

Several studies have shown some benefit:

Green light lasers

At 532 and 532/1064 nm, several green light lasers have been studied.

Yellow light sources

These are generally low-fluence pulsed dye lasers (PDL) at 585-595nm.

Intense Pulsed Light

Intense Pulsed Light (IPL) devices use light and heat, known as LHE technology, to trigger the destruction of the P. acnes bacteria.

Lasers that destroy sebaceous glands

Several laser systems have been used to treat inflammatory acne vulgaris by destroying the sebaceous glands including near-infrared lasers, 1320nm CoolTouch®, 1450nm SmoothBeam®, 1540nm erbium glass Aramis® and radiofrequency devices.

1450nm SmoothBeam® laser

Indocyanine green (ICG) + diode laser (810nm-900nm)

ICG, a fluorescent dye used for imaging purposes, acts as a sensitizing agent to help target the sebaceous glands. The combined use of ICG with diode lasers showed a reduction in inflammatory acne vulgaris lesions

Radiofrequency devices

A monopolar radiofrequency (RF) with ThermaCool® device has been trialled:

Related information

Make a donation

Donate Today

Help us to update and maintain DermNet New Zealand

The History Of DermNet

Watch Dr Amanda Oakley presenting 'The History Of DermNet NZ' at The International Society Of Teledermatology.

Subscribe to our mailing list

* indicates required
DermNet NZ Newsletter