Light Therapy and Advanced Modalities

The Electromagnetic Spectrum

Light is electromagnetic radiation measured in nanometers (nm) of wavelength. Shorter wavelengths carry more energy. Estheticians work with visible light (about 400-700 nm) and the invisible bands just outside it.

• Ultraviolet (UV) light: below 400 nm, invisible, highest energy of the three salon-relevant bands. Causes tanning, burning, and roughly 80-90% of visible skin aging (photoaging).
• Visible light: 400-700 nm, the colors you see; used in LED therapy.
• Infrared (IR): above 700 nm, invisible, felt as heat; penetrates deep and relaxes tissue.

UVA vs UVB

This is why broad-spectrum SPF is non-negotiable after any exfoliating or light treatment.

LED Light Therapy

LED (light-emitting diode) therapy delivers specific wavelengths of low-energy visible light to trigger cellular responses without heat or downtime. It does not remove skin like a peel; it is non-ablative.

• Red light (~630-660 nm): stimulates fibroblasts to produce collagen, increases circulation, and reduces inflammation — used for anti-aging and healing.
• Blue light (~405-420 nm): destroys Cutibacterium acnes (formerly Propionibacterium acnes), the bacteria behind inflammatory acne.
• Green/amber light: targets pigmentation and redness.

LED safety

The client must wear protective goggles because direct light can damage the retina. LED therapy is contraindicated for clients on photosensitizing medications (isotretinoin/Accutane, certain antibiotics, retinoids), those with epilepsy (light flicker risk), and active skin cancer. It is painless and requires no recovery time, which makes it a safe finishing step.

Unlike a laser, which emits a single coherent, focused wavelength capable of cutting or penetrating the dermis, LED light is diffuse and non-coherent and stays at the surface. That difference is exactly why LED is in your scope and laser is not. IPL (intense pulsed light) sits in between — it uses broad-spectrum light to target pigment and vessels, but because it can reach the dermis it is generally a medical/physician-delegated procedure in Texas.

Microdermabrasion

Microdermabrasion is a mechanical exfoliation that sprays or rubs fine crystals (or uses a diamond-tipped wand) across the skin and vacuums away dead cells. In Texas it is allowed only when it removes dead cells from the outermost epidermis and does not pierce the dermis — this is the bright line drawn by 16 TAC 83.112(c).

Step-by-step procedure:

1. Cleanse and dry the skin completely.
2. Set the vacuum to an appropriate suction level for the client's skin.
3. Hold the skin taut and move the wand in even passes, avoiding the eye orbit.
4. Reduce passes over thin or sensitive areas.
5. Soothe, apply serum, and finish with broad-spectrum SPF.

Contraindications: active acne pustules, rosacea, fragile/couperose skin, recent isotretinoin use, blood-thinner use (bruising/bleeding risk), and any broken or inflamed skin.

Superficial Chemical Peels

Texas estheticians may perform light/superficial peels that beautify the epidermis only and do not penetrate the dermis. Deeper (medium/deep) peels are medical procedures.

The common acids and their type:

• AHAs (alpha hydroxy acids) — glycolic, lactic acid: water-soluble, surface exfoliation, good for dryness and pigmentation.
• BHA (beta hydroxy acid) — salicylic acid: oil-soluble, penetrates pores, ideal for oily/acne skin.
• Enzyme peels — papain, bromelain: gentlest, dissolve dead cells, suitable for sensitive skin.

Peel safety and the dermis line

Do a patch test, wear gloves, and have a neutralizer ready. Avoid peels on clients who recently waxed, used retinoids, or had sunburn. Remember 83.112 lists prohibited items too: MMA monomer, razor-type callus shavers (credo blades), and stick/lump alum are banned — these appear as distractors on advanced-modality questions.

The Fitzpatrick scale (skin types I-VI, lightest to darkest) guides peel and light intensity. Types IV-VI carry a higher risk of post-inflammatory hyperpigmentation (PIH) — darkening after inflammation — so aggressive exfoliation and certain light wavelengths must be dialed back. Always pair any exfoliating or light treatment with daily broad-spectrum SPF, or you will trade one problem for hyperpigmentation.

Step-by-step superficial peel

1. Consult, review medications, and confirm no photosensitizers or recent waxing.
2. Cleanse and degrease the skin so the acid contacts evenly.
3. Apply the acid in thin, even layers with a gloved hand or fan brush; start your timer.
4. Watch for endpoints (light frosting/erythema) and never exceed the label's maximum time.
5. Neutralize (for acids that require it), then soothe, hydrate, and apply SPF.

A peel left on too long can drive past the epidermis — a scope violation and a safety hazard. When in doubt, do fewer passes and shorter contact time.

Common Mistakes and Exam Traps

• Calling laser hair removal an esthetician service — it is not; it penetrates the dermis and needs a physician.
• Forgetting goggles under LED.
• Mixing up red (collagen/anti-aging) and blue (acne bacteria) light wavelengths.
• Performing aggressive exfoliation on a client using retinoids or isotretinoin.
• Letting microdermabrasion break the skin — that crosses into the dermis and violates 83.112(c).

Why It Matters

The exam ties every advanced modality back to two ideas: work above the dermis and screen for photosensitivity and bleeding risk. If a procedure penetrates living tissue or a client is on photosensitizing drugs, the correct answer is almost always to refer out or decline.