☀️ NB-UVB Phototherapy Starting Dose Calculator Simulator

Starting Dose by Fitzpatrick Phototype

Baseline NB-UVB dose scales with skin phototype.

• I–VI: Phototypes (Fitzpatrick scale)
• ~100 mJ: Type I dose (lowest starting dose)
• ~300 mJ: Type VI dose (highest starting dose)
• ~20%: Increment step (per visit, typical)

Phototype lookup

Darker phototypes tolerate higher initial UV-B doses.

Always confirm phototype by patient history, not visual estimate alone.

Minimal Erythema Dose Reference Chart

MED anchors the starting dose calculation per patient.

• Lowest UV: MED definition (dose causing erythema)
• ~200 mJ/cm²: Type I MED (reference chart value)
• ~600 mJ/cm²: Type VI MED (reference chart value)
• Phototest: Test method (or phototype estimate)

MED chart use

Chart-based MED is used when phototesting is unavailable.

Measured MED is preferred over chart estimates when feasible.

Percentage-of-MED Starting Protocol

Standard protocols start at 50% of estimated MED.

• 50%: Standard start (of estimated MED)
• 25–30%: Conservative start (for sensitive patients)
• 10–20%: Increase per visit (if no erythema)
• ~40 mJ: Max increase cap (per session, typical)

Percent-based dosing

Dose escalation follows tolerance and erythema response.

Reduce percentage if prior erythema or missed sessions occurred.

Body Site Sensitivity Adjustment

Sensitive body sites require lower starting doses.

• Face, neck: High-sensitivity sites (and flexural areas)
• ~30%: Reduction factor (typical dose reduction)
• Trunk, limbs: Standard sites (full calculated dose)
• Genitalia: Shielding advised (routinely shielded)

Site-specific dosing

Adjust dose downward for thin or sensitive skin regions.

Sensitive-site burns are a leading cause of treatment interruption.

Initial Dose Confirmation

Final adjusted dose is confirmed before first exposure.

• Phototype +: Final check (site adjustment combined)
• Chart entry: Documentation (recorded per session)
• Each visit: Review interval (reassess tolerance)
• Built-in: Safety margin (below erythema threshold)

Confirmed starting dose

Adjusted dose is logged and used for session one.

Confirm no photosensitizing medications before starting treatment.