Iontophoresis is a technique that uses an electrical current to move substances across the skin or other body surfaces such as the eye. Although the effect was first noted in the eighteenth century, its use in medicine only became popular after 1900, following the publication of a series of papers on the subject by the French physician Stéphane Leduc.
Iontophoresis only works on ions – water-soluble substances that have a positive or negative charge – and is based on the general principle that like charges repel and unlike charges attract. By using a direct (galvanic) current, an ion can be ‘pushed’ into the skin if the electrode (the active or working electrode) being used has the same charge as the ion in question, i.e. a positive ion (cation) will be pushed into the skin by a positive electrode (anode) and a negative ion (anion) will be similarly affected by a negative electrode (cathode). In some cases therapists refer to each process separately – cataphoresis when the positive electrode is the working electrode (it pushes cations) and anaphoresis for when the negative electrode is used (it pushes anions) – but as this is rather confusing both processes are often simply referred to as iontophoresis.
Working electrodes come in a variety of forms ranging from balls, rollers and disks to full face masks. As a direct current is used, another electrode (the passive, indifferent or return electrode) is required to complete the electrical circuit and get the current to flow. This electrode can be a bar which is given to the client to hold or a pad which is placed somewhere where it makes good body contact, such as under the shoulder or wrapped around the upper arm.
Because it is very difficult to move water-soluble chemicals across the skin’s surface, iontophoresis was considered by many to be a promising method for delivering drugs when it was first introduced. Unfortunately, due to a variety of factors, including the excellent barrier properties of the skin, this has not held up in practice and it currently has only limited applications within medicine – such as treatments for hyperhidrosis (abnormal sweating of the palms or other areas of the body).
Electricity had been used to increase skin penetration before the arrival of iontophoresis in salons. The main aim of this treatment was to redden the skin thereby increasing absorption through increased blood flow. So, even if some ions were moved in the process, it was not a true iontophoresis treatment.
After the paste has become thoroughly dry it may be removed by washing the skin with luke-warm water, and then if the patches on the face or neck are very deep, the bleaching lotion may be forced into the skin by means of the negative electrode, … continuing the process until the skin is thoroughly reddened. This process, it should be understood, is only used for moth patch or chloasma, and would not be used in the ordinary treatment at all.
Red light was used in a similar fashion to redden skin with the idea that this would increase absorption.
See also: Red Light, Blue Light
The earliest record I have for iontophoresis being used as a salon practice is by Helena Rubinstein in 1935, but it is possible that it was a treatment regime in French salons before this. Exactly what ingredients were used in these early salon treatments has so far eluded me but I suspect they were nothing startling. Clients were probably sold on the general idea that iontophoresis would increase the penetration of whatever cream or gel was being used in the facial or body treatment at the time. Heat produced during the treatment can also result in skin reddening which clients would be told was having a regenerating effect on the skin.
Iontophoretic ingredients used in salon treatments today include such things as vitamins, minerals, collagen, elastin, amino acids, hyaluronic acid and a range of animal and plant extracts. They come pre-prepared in a range of forms, e.g. gels, serums, ampoules, etc. Therapists are usually provided with very little information as to how these work, other than the skin condition on which they are to be applied and the polarity of the electrode to be used. As with many ingredients in skin creams, it is doubtful that some of these substances could penetrate the skin, whether a current is used or not, let alone whether they would be effective.
Claims for iontophoretic treatments include hydration, repair and regeneration of mature or damaged skin, stimulation of sluggish circulation and, in the case of body treatments, the softening and absorption of fat and cellulite. Many of these claims are suspect, given that they rely on the transfer and action of specific ingredients deep into the skin.
Iontophoretic treatments which required the operator to reverse the polarity of the electrode – change from negative to positive or positive to negative – are particularly dubious as the opposing polarity would begin to reverse any effect previously generated and ions that were hitherto ‘pushed’ into the skin would now be ‘pulled’ out of it.
Another galvanic treatment that appeared contemporaneously with the introduction of iontophoresis was ‘De-incrustation’. According to reports, this new treatment, developed by the Société P.A.B. in France, used a direct current to remove ‘incrustations’ from the skin.
The developers of the treatment described these ‘incrustations’ as ‘microscopic crystallisations’ formed by chemical reactions between certain chemicals and minerals in creams, make-up, atmospheric pollution and perspiration. As the impurities built up in the skin they adversely affected it and so required removal, that is, the skin needed to be ‘de-incrustated’.
The chief characteristics of the method consist in breaking up, reducing and eliminating all the impurities (waste matter, dust, toxins, crystallisations, etc.) which block up the glandular tubes. … The immediate result is—increased blood circulation and, gradually, recolouring of the epidermis.
The treatment became another established practice within Beauty Culture. Later known as disincrustation or desincrustation it uses another well known effect of direct (galvanic) currents.
Desincrustation relies on the fact that when a direct current is used an alkali (sodium hydroxide) is produced at the negative electrode and an acid (hydrochloric acid) is generated at the positive electrode.
This chemical reaction was well known to science in the nineteenth century and was the basic science behind the electrical removal of unwanted hair using electrolysis.
See also: Electrolysis
Unlike electrolysis, where the sodium hydroxide (lye) is concentrated in a small area in the living dermis of the skin through the insertion of a needle, in desincrustation the sodium hydroxide is spread over the stratum corneum of the epidermis – which is dead tissue – using a swab, roller or something similar. So, rather than destroying tissue, as in electrolysis, the effect of the sodium hydroxide in desincrustation is merely to soften the keratin in the epidermis. This assists in desquamating surface keratinocytes and in loosening any hard plugs of sebum that occur in blackheads. The treatment is therefore commonly employed as precursor to extractions.
The negative electrode used in desincrustation can be a disk, roller or ball electrode, a full facial mask or something a simple as a tweezer electrode encased in a pad of cotton wool soaked in conducting solution. Unlike iontophoresis, where specialised ampoules are needed, a simple salt solution is all that is required.
In order to carry out either desincrustation or iontophoresis a salon will need to purchase a galvanic machine. Having done so it makes sense for them to maximise the return on their outlay by combining iontophoresis and desincrustation into a single treatment. Commonly, this is done by first carrying out desincrustation using the negative electrode and then following this with iontophoresis using only the positive electrode.
This has two main benefits. Using desincrustation first helps reduce the barrier properties of the skin, in theory making it easier for ions to move across the skin during iontophoresis. Then, as acid is produced under the positive electrode, following desincrustation with iontophoresis using only the positive electrode helps restore the acid balance of the skin upset by the sodium hydroxide generated during desincrustation.
Updated: 4th June 2014
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