12.5 Infrared, Ultraviolet & LED Light Therapy Equipment

12.5 Infrared, Ultraviolet & LED Light Therapy Equipment

CIDESCO Exam Tip: The CIDESCO syllabus names "Ultra Violet and Infra Red Light Therapy" alongside galvanic, high frequency and muscle stimulation. Learn the two physical laws that govern all radiant treatments, the waveband boundaries in nanometres, the safe operating distances, and why a UV cabinet is a storage box rather than a steriliser.

Galvanic and high-frequency machines deliver energy by conduction through tissue. Infrared, ultraviolet and LED equipment instead deliver radiant energy - electromagnetic waves that travel through air and are absorbed at the skin surface. Because nothing touches the client, the therapist controls dose entirely through distance, angle and time.

The Electromagnetic Spectrum in the Treatment Room

  <-- shorter wavelength, higher energy        longer wavelength, lower energy -->
  |  UVC   |  UVB   |   UVA   | VISIBLE LIGHT |     INFRARED (IR-A / IR-B / IR-C)   |
  100-280   280-315   315-400     400-780        780 nm ------------------> 1 mm
     nm       nm        nm          nm
  filtered  sunburn   ageing     blue 415 nm    IR-A penetrates dermis;
  by ozone   DNA      MMPs       red 633 nm     IR-C absorbed at surface

Two Laws Governing Every Radiant Treatment

1. The Inverse Square Law: the intensity of radiation reaching a surface is inversely proportional to the square of the distance from the source. Halving the lamp distance quadruples the intensity; doubling it reduces intensity to one quarter. This is why a small change in lamp position is not a small change in dose, and why the distance is measured rather than estimated.
2. Lambert's Cosine Law: maximum absorption occurs when the rays strike the tissue perpendicularly, at 90 degrees. As the angle becomes oblique, the same energy is spread over a larger area and absorption falls. The lamp head is therefore aligned square to the treatment area, not angled across it.

Infrared Radiation

Infrared radiation is absorbed by tissue and converted directly into heat. Two lamp types are used.

Physiological Effects

• Cutaneous vasodilation and hyperaemia, raising local tissue temperature and metabolic rate.
• Relaxation of hypertonic skeletal muscle, making subsequent massage more comfortable and effective.
• Mild sedation of sensory nerve endings, giving analgesia.
• Increased eccrine sweating and increased skin permeability, so products applied afterwards absorb more readily.

Application Protocol

1. Perform a thermal sensation test on the treatment area using warm and cool test tubes. If the client cannot reliably distinguish them, do not proceed.
2. Position the lamp at 45-90 cm (roughly 18-36 inches) with the head square to the area.
3. Treat for 10-20 minutes, checking the client's comfort and skin colour every few minutes. The sensation should be comfortably warm and never hot.
4. Provide eye protection with damp cotton pads and never direct the lamp at the eyes.
5. Warm the lamp up before it faces the client, and never move a hot lamp across the client's body.

Contraindications to Infrared

Defective cutaneous sensation, impaired peripheral circulation, recent or immature scar tissue, acute inflammation or infection, fever, migraine or headache, severe hypertension or heart disease, oedematous or dehydrated tissue, metal implants in the field, pregnancy, sunburn, and immediately after a chemical peel or waxing.

Ultraviolet Radiation

Ultraviolet radiation is non-thermal and produces chemical and photobiological effects. Its three bands are defined by wavelength.

Legitimate Uses of UV in Aesthetic Practice

• Wood's lamp diagnosis: filtered long-wave UVA with peak emission at 365 nm, used in a darkened room to interpret fluorescence during skin analysis.
• UV nail lamps: UVA around 365 nm, or LED units around 405 nm, used to cure gel polish photo-initiators.
• UV storage cabinets: approved for storing implements that have already been cleaned and disinfected. A UV cabinet does not sterilise, does not penetrate shadowed surfaces, and must never be recorded as a decontamination step.

Risks and Regulation of Tanning Equipment

In 2009 the World Health Organization's International Agency for Research on Cancer classified UV-emitting tanning devices as Group 1 carcinogens, the highest category, alongside tobacco and asbestos. Many jurisdictions prohibit commercial sunbed use by anyone under 18. Beauty therapists should understand that no UV exposure produces a "safe" tan: melanin darkening is a DNA damage response.

Photosensitising agents dramatically amplify UV response and must be screened for at consultation: tetracycline and quinolone antibiotics, thiazide diuretics, retinoids, St John's wort, and psoralen-containing plant oils such as bergamot.

LED Phototherapy (Low-Level Light Therapy)

LED phototherapy uses narrow-band, non-coherent, non-thermal visible and near-infrared light to drive photobiomodulation. Light is absorbed by cytochrome c oxidase in the mitochondrial inner membrane, raising ATP output.

LED sessions typically run 15-20 minutes with the panel 5-15 cm from the skin per manufacturer instruction, with goggles worn. It is contraindicated in epilepsy (flashing modes), during photosensitising medication, over active malignancy, and in pregnancy per most manufacturers.

Safety rule that applies to all three modalities: eye protection is not optional. Infrared damages the lens and retina through heat, UV causes photokeratitis and cataract, and high-intensity LED arrays cause retinal glare injury.