Medical Research
 

Pigmented blemishes

Definition

Hyperpigmentations (or blemishes) are localised scars resulting from an imbalance in melanin production that cannot be repaired by skin cells. This melanin production is regulated by a complex hormonal mechanism; it’s very sensitive to stress, to certain medications, to the use of perfume and to anything that can cause endocrinal imbalance – not forgetting environmental factors like sunlight.

These lesions are mainly found on exposed areas: face, décolletage, forearms and hands. They often appear after middle age on the back of the hands and face. Contraceptive pills or pregnancy can trigger fairly large, brown hyperpigmentation on the forehead and cheekbones, which is accentuated by the sun.

The most common disorders are actinic lentigines. Pigmented lesions can be superficial, limiting themselves to the epidermis; others are deeper because they’re anchored in the dermis. These are more difficult to remove as they represent a specific type of melasma.

Therapeutic application for P-O75

The medical claim for P-O75 is for the treatment of flat and benign cutaneous pigmented blemishes.

Before any treatment, it’s important to make sure that the pigmented lesions are benign.

Different techniques are used to reduce inflammatory scarring or to revive stagnant cicatricial processes; pulsed light is one of the treatments that respond to this process.

P-O75 can be used to treat:

  • Actinic lentigo (sun spots),
  • Senile lentigo (age spots),
  • Superficial melasma (appearing during pregnancy or while on the contraceptive pill),
  • Long-term ephelides (deep red spots).

P-O75 is not designed to establish a medical diagnosis, but to treat the conditions described above.

Operating P-O75

P-075’s characteristics mean that it’s possible to select only a portion of the light spectrum emitted by a flash tube at the moment of flashing. This is achieved by interposing one or more filters between the tube and the skin.

Optimum filtration provides a spectrum of light that’s absorbed selectively by the target (the melanin of the lesions) to the exclusion of the natural skin melanin.

P-O75 has a filtration system adapted to the clinical condition being treated.

Taking into account the absorption spectra of all the elements that constitute skin, it’s necessary to keep the wavelengths <420 nm when applied to pigmentary defects.

Finally, as also explained in the technical manual, P-O75’s flash duration is determined by the treated target and correlates with the perfect homogeneity of the luminous intensity of the emitted flash.

Clinical evaluation

Clinical evaluation was based on:

  • A critical evaluation of the relevant scientific literature currently available on the safety and performance of devices offering similar or equivalent technologies and treating similar or equivalent conditions to those of P-O75:
     
    • Equivalence of the products to which the data relates
    • Compliance with the relevant essential requirements.
  • Tests carried out with other medical devices that use the same IPL technology for the same conditions.

Context

Pulsed light has been used for 20 years, either alone or in conjunction with other techniques or medication to treat minor ailments or disorders such as: hirsutism and hairiness, wrinkles, pigmented lesions, vascular lesions.

The light produced by pulsed light devices is absorbed by melanin (hairiness, pigmented lesions), by water in the dermis (sagging) or by haemoglobin (vascular lesions). The light energy is then converted into thermal energy, which – depending on the temperature reached – can:

  • stimulate collagen generation (treatment for wrinkles or sagging skin):
  • cause the destruction of melanocytes containing excess melanin in pigmented lesions
  • or, at higher temperatures, cause coagulation of proteins (treatment for hairiness or vascular lesions).

Just like with laser, IPL dims pigmented lesions by destroying the excess melanin they contain. However, treatment of pigmented lesions by pulsed light is more effective than other treatments (depigmentation creams, cryotherapy, chemical peels) because it protects the surrounding skin; follow-ups are especially light. Another advantage of pulsed light is the much larger treatment surface than with laser, allowing faster treatment of a set of lesions, for example; side effects are also much less than those linked to laser.

Safety

Safety is checked at several levels:

  • Safe use in relation to using a class II active medical device (non-invasive). The product risk analysis has shown that the main safety-related risks are electric shock and a rise in temperature. This is why the product has been subjected to testing by an external independent laboratory (tests carried out by LCIE on E-O75, whereby P-O75 uses the exact same internal electronic base) to ensure its compliance with reference standards (mainly 60601-1). These tests have proven conformity each time, thus confirming compliance with design rules applied beforehand, whether at a material, software or mechanical level.
  • As for safety of the treatment, the risk of overheating or even burning was taken into account and assessed during the risk analysis. No unacceptable risk was identified after the application of control methods.

Performance

P-O75’s flash duration is determined in relation to the treated target (the melanin), and is correlated with the perfect homogeneity of the luminous intensity of the emitted flash.

Optimum filtration provides a spectrum of light that’s absorbed selectively by the target.

The chance of reduced performance has only one possible source: insufficient flash power. The cause is an incorrect setting on the device during manufacturing: set to a lower power.

This point is checked by the Production team, who will adjust the level of energy delivered if necessary. In particular, the instruction "Verification and settings of P-O75" describes the elements to be controlled during production, including the energy adjustment mode.

Each P-O75 is set to ensure a strong enough current to guarantee the effectiveness of the flash.

General conclusion

Literature on the effectiveness and safety of pulsed light to treat pigmentary disorders is numerous and has been regularly published over the last 15 years.

In particular, it is safe and effective for the treatment of benign pigmentary disorders, including conditions treated by P-O75.

Also, the literature shows that treatment for pigmented lesions and skin ageing are generally related. P-O75 treats areas of the face, hands and décolletage. In the vast majority of cases, pigmented lesions found on these 3 areas are solar lentigines due to excessive sun exposure resulting in premature ageing of the skin.

Side effects are almost always systematic. However, they are bearable and temporary (there has never been any scarring), so the benefits of using the device outnumber the disadvantages.

When the lesions are dark and/or acquired, pulsed light produces excellent results in 1 or 2 sessions. There is no social exclusion. Lesions reappear over time and treatment can then be renewed. However, the best way to avoid recurrences is to avoid exposure to the sun.

Finally, the need to properly identify the type of pigmented lesion beforehand is also highlighted. For this reason, E-Swin has decided to make P-O75 available only to doctors, who will then be able to make a preliminary diagnosis. Doctors are indeed in the best position to check pigmented lesions prior to treatment.

In addition, P-O75 meets the electrical safety and performance specifications that have been indicated.

Above all, it was designed and will be manufactured according to electrical safety and electromagnetic compatibility standards, 60601-1 and 60601-1-2 respectively.

The records for P-O75 risk management conclude that, given the risk reduction achieved after application of risk control measures, in addition to the low level of residual risks, and considering the safety measures (including power limitation, filtration, anti-tamper system), this analysis has made it possible to implement risk control measures during the design and assembly phases. These measures have helped to reduce the identified risks to an acceptable level.

A number of these risks (although classified as acceptable) are subject to a series of warnings in the user manual; each warning is easily identifiable when reading the user manual by its logo, as defined by the standard.

The user manual contains the medical claim, the risks, how to use P-O75 and contraindications.

P-O75 enables fast and effective results. An additional session can be performed if needed, but only after a 10-day interval. This protocol is also explained in the user manual.