What are the recommendations for skin protection and medication based on Fitzpatrick skin type (Fitzpatrick Skin Type Classification)?

Fitzpatrick Skin Type: Clinical Recommendations for Skin Protection and Phototherapy

The Fitzpatrick Skin Type Classification directly determines starting doses and dose escalation protocols for phototherapy, with Type I skin requiring the lowest initial doses (0.5 J/cm² for PUVA, 130 mJ/cm² for NB-UVB) and Type VI requiring the highest (3.0 J/cm² for PUVA, 400 mJ/cm² for NB-UVB), while all skin types require rigorous sun protection with broad-spectrum SPF 30+ sunscreen regardless of baseline pigmentation. 1, 2

Phototherapy Dosing Based on Fitzpatrick Skin Type

PUVA (Psoralen + UVA) Initial Dosing Protocol

The following starting doses and incremental increases are standardized based on skin type 1:

• Type I: Start 0.5 J/cm², increase by 0.5 J/cm² per treatment
• Type II: Start 1.0 J/cm², increase by 0.5 J/cm² per treatment
• Type III: Start 1.5 J/cm², increase by 1.0 J/cm² per treatment
• Type IV: Start 2.0 J/cm², increase by 1.0 J/cm² per treatment
• Type V: Start 2.5 J/cm², increase by 1.5 J/cm² per treatment
• Type VI: Start 3.0 J/cm², increase by 1.5 J/cm² per treatment

Narrowband UVB Initial Dosing Protocol

The following starting doses apply for NB-UVB phototherapy 1:

• Type I: Start 130 mJ/cm², increase by 15 mJ/cm² per treatment
• Type II: Start 220 mJ/cm², increase by 25 mJ/cm² per treatment
• Type III: Start 260 mJ/cm², increase by 40 mJ/cm² per treatment
• Type IV: Start 330 mJ/cm², increase by 45 mJ/cm² per treatment
• Type V: Start 350 mJ/cm², increase by 60 mJ/cm² per treatment
• Type VI: Start 400 mJ/cm², increase by 65 mJ/cm² per treatment

Broadband UVB Dosing

For BB-UVB therapy, the protocol differs 1:

• Type I: Start 20 mJ/cm², increase by 5 mJ/cm²
• Type II: Start 25 mJ/cm², increase by 10 mJ/cm²
• Type III: Start 30 mJ/cm², increase by 15 mJ/cm²
• Type IV: Start 40 mJ/cm², increase by 20 mJ/cm²
• Type V: Start 50 mJ/cm², increase by 25 mJ/cm²
• Type VI: Start 60 mJ/cm², increase by 30 mJ/cm²

Critical Safety Considerations by Skin Type

Types I-II (Lightest Skin)

These patients require the most cautious approach with lowest starting doses and smallest incremental increases due to minimal melanin protection and highest burn risk. 2

• Burn easily with minimal sun exposure, making them highly susceptible to photosensitivity reactions 2
• Require careful monitoring for erythema and adverse reactions during any phototherapy treatment 2
• Must use daily broad-spectrum sunscreen (minimum SPF 30) containing zinc oxide or titanium dioxide on all exposed skin regardless of season 2
• Physical sun avoidance is strongly recommended, including protective clothing and wide-brimmed hats 2

Types III-VI (Darker Skin)

Patients with darker skin types experience significant delayed tanning responses and specific pigmentary complications that require monitoring. 1

• Types III-VI demonstrate significant delayed tanning response during PUVA therapy 1
• Types IV-VI are prone to nail changes (photo-onycholysis and melanonychia) affecting multiple nails during PUVA, which are fully reversible upon discontinuation 1
• Nail lacquer application may prevent UVA exposure to nails and reduce these changes 1
• Mottled hypo- and hyperpigmentation can occur as early as 4 weeks into therapy across all darker skin types 1

Universal Sun Protection Requirements

All Fitzpatrick skin types require comprehensive sun protection, as the classification gives a false sense of security particularly for darker skin types regarding skin cancer risk. 3

Mandatory Protection Measures

• Apply broad-spectrum sunscreen (minimum SPF 30) daily to all exposed skin areas 2
• Reapply sunscreen every 2 hours during sun exposure 2
• Use physical barriers including protective clothing and wide-brimmed hats 2
• Avoid direct sunlight when possible, particularly during peak UV hours 2

Genital and Facial Shielding During Phototherapy

• Male patients must use genital shields during all PUVA treatments due to elevated risk of squamous cell carcinoma of the genitalia 1
• Cover the face during phototherapy when facial lesions are absent, as facial skin responds to lower UV doses 1
• All patients must wear UV-protective goggles during treatments 1

Treatment Frequency and Scheduling

PUVA Therapy

• Treat at least 48 hours apart (preferably 72 hours) to allow assessment of photoreactions from previous treatment 1
• Twice weekly treatments are standard and safer, though three times weekly clears disease faster 1
• Administer 8-MOP at 0.6 mg/kg with UVA exposure 2 hours later, or Oxsoralen-Ultra at 0.5 mg/kg with exposure 1-1.5 hours later 1

NB-UVB Therapy

• Three times per week on nonconsecutive days is standard protocol 1
• Twice weekly suffices but clears disease more slowly 1
• Treatment frequency directly impacts time to clearance but not necessarily total cumulative dose 1

Limitations of Fitzpatrick Classification

The Fitzpatrick scale has significant limitations in clinical practice, particularly for patients with skin of color, as it was originally developed only for white skin to guide PUVA dosing. 3, 4

• 59% of Black adults in one study could not classify themselves into any of the four Fitzpatrick types when given the option "none of the above" 4
• The scale's reliance on European-cultural terms "suntan" and "sunburn" limits its utility and validity with diverse populations 4
• Skin cancer risk is not accurately predicted by Fitzpatrick type alone, particularly in darker skin types 3
• The classification may provide false security that people of color have minimal skin cancer risk 3

Missed Treatment Adjustments

When treatments are missed, adjust dosing as follows 1:

• 4-7 days missed: Keep dose the same
• 1-2 weeks missed: Decrease dose by 50%
• 2-3 weeks missed: Decrease dose by 75%
• 3-4 weeks missed: Start over at initial dose

Long-Term Risks Across All Skin Types

Skin Cancer Risk

• High cumulative PUVA exposure increases squamous cell carcinoma risk 14-fold compared to low-dose PUVA 1
• 26% of patients on continuous PUVA maintenance (every 6 weeks) developed non-melanoma skin cancer 1
• Melanoma risk increases after 15 years of PUVA exposure or with high cumulative doses 1
• NB-UVB shows no significant association with skin cancer at median 5.5 years follow-up 1

Other Complications

• Photoaging occurs with long-term PUVA, manifesting as wrinkling, telangiectasia, and histologic elastosis 1
• Pigmentary changes including immediate and persistent pigment darkening affect all skin types 1