Reading Fitzpatrick Skin Types Before You Treat

The scale

The Fitzpatrick classification sorts skin by how it responds to sun, which is a practical proxy for how much melanin the epidermis carries and how readily it makes more:

• Type I always burns, never tans
• Type II burns easily, tans minimally
• Type III sometimes burns, tans gradually
• Type IV burns minimally, tans easily
• Type V rarely burns, tans deeply
• Type VI never burns, deeply pigmented

Type the client, not the market. A clinic in Southeast Asia will still meet Type II clients, and a clinic in Scandinavia will meet Type V. The person's skin in front of you sets the protocol.

Why it changes everything

Epidermal melanin is a competing chromophore. Every joule it absorbs is a joule that never reaches your target, and enough of those absorbed joules mean a burn, blistering or post-inflammatory hyperpigmentation. On light skin the competition is weak and parameters can be assertive. On dark skin the competition is strong and the treatment window narrows. The skill is not avoiding dark skin; it is re-solving the photothermolysis equation for it.

What changes, practically

Wavelength. Move longer. 1064nm is the pigment and hair-removal wavelength of choice for dark skin precisely because epidermal melanin absorbs it weakly. The 532nm line, so useful on freckles in Type I-III, is off the table for dark skin.

Pulse width. Lengthen it. A longer pulse lets the epidermis conduct heat away between absorbed photons while the larger target accumulates damage. This is why our diode platform stretches to 200ms.

Fluence. Start lower than the textbook value for the indication and climb across sessions as the skin proves itself.

Cooling. Non-negotiable. Contact cooling before, during and after the pulse is what buys back the safety margin that darker epidermis spends.

Two traps that catch new clinics

Tanned skin is darker skin. A Type III client back from a beach holiday treats like a Type IV. Our screening checklist asks about sun exposure for exactly this reason, and recent tanning is a reason to reschedule, not to lower the fluence and hope.

Melasma is not a freckle. Melasma flares with aggressive treatment, including treatment that would be safe on ordinary sun spots. Low-fluence toning protocols and maintenance planning exist for it, and chasing it with assertive pigment settings makes it worse. When in doubt, refer.

The test spot discipline

On any client past Type III, treat a small, discreet area first and review it at the interval your protocol specifies. The test spot costs you ten minutes and tells you what the skin actually does rather than what the chart predicts. Every Pmise platform ships with training that builds test spots into the workflow, because the factories that skip this chapter are the ones whose machines end up in forums for the wrong reasons.