What are the treatment options for sun allergy?

Sun Allergy Treatment

For polymorphic light eruption (PLE), the most common sun allergy, initiate topical corticosteroids for acute flares and implement strict photoprotection, with phototherapy reserved for prophylaxis in severe cases. 1, 2

Acute Management

Topical Corticosteroids

• Apply potent topical corticosteroids immediately to affected areas when lesions appear 1
• Topical corticosteroids are the mainstay of acute therapy for PLE and other photodermatoses 2
• For severe provocation episodes, use potent topical steroids and consider omitting one or two phototherapy treatments if the patient is undergoing desensitization 1

Systemic Corticosteroids

• Oral corticosteroids (prednisolone 40-50 mg) can be used for the first 2 weeks when initiating phototherapy to prevent provocation 1
• Pruritus associated with photodermatoses can be managed with oral corticosteroids 1
• For chronic actinic dermatitis, prednisolone 20-30 mg on the day of phototherapy is recommended 1

Photoprotection (Essential for All Patients)

Sunscreen Application

• Apply broad-spectrum sunscreens with SPF ≥30 daily to all exposed skin areas, regardless of season 1, 3
• Use hypoallergenic formulations containing zinc oxide or titanium dioxide, PABA-free with UVA/UVB protection 1
• Sunscreens are most effective for sunburn prevention and provide significant benefit for preventing actinic keratoses and squamous cell carcinomas 4

Behavioral Modifications

• Avoid sun exposure during peak hours (10 AM to 4 PM) 3
• Wear protective clothing including broad-brimmed hats, long-sleeved shirts, and long pants 3
• Seek shade consistently and avoid sunlamps and tanning beds 3

Prophylactic Phototherapy (For Recurrent/Severe Cases)

PUVA Therapy

• PUVA administered 2-3 times weekly for 12-20 treatments can provide desensitization for PLE 1
• Timing is critical: administer in early spring in temperate climates to maintain protection through summer 1
• Risk of provocation is 12-50% during PUVA courses, requiring careful monitoring 1
• Post-treatment, continue cautious natural sunlight exposure to maintain tolerance 1

Narrowband UVB (Preferred Alternative)

• Narrowband UVB is equally effective as PUVA with a better safety profile 5
• The British Journal of Dermatology recommends narrowband UVB as first-line phototherapy due to lower long-term carcinogenesis risk 5
• Both PUVA and narrowband UVB show 88-89% good or moderate improvement at follow-up 1

Special Considerations by Condition Type

Solar Urticaria

• Determine action spectrum and minimum urticarial dose (MUD) before initiating phototherapy 1
• Start phototherapy at doses lower than the MUD to prevent provocation, syncope, or anaphylaxis 1
• Antihistamines are standard therapy alongside photoprotection 1

Chronic Actinic Dermatitis

• Requires specialist unit management with topical or systemic corticosteroid cover 1
• Small dose increments (0.05 J/cm²) with each UVA exposure 1
• May require inpatient supervision initially, though not always necessary 1
• Maintenance treatment may be needed, but balance benefit against long-term skin cancer risk 1

Phototoxic/Photoallergic Reactions

• Immediately discontinue any suspected photosensitizing medications (antibiotics, cardiovascular drugs, antidepressants) 3, 6
• Apply anti-inflammatory dressings and corticosteroid ointments 6
• True photoallergy to sunscreens is rare despite popular belief; most reactions are irritant rather than allergic 7

Maintenance and Follow-Up

Skin Care Regimen

• Use gentle, pH-neutral soaps and tepid water for bathing 1
• Apply hypoallergenic moisturizing creams daily to prevent skin dryness 1
• Wear fine cotton clothing instead of synthetic materials 1

Surveillance

• Annual dermatologic examinations are recommended for patients with chronic photosensitivity due to increased skin cancer risk 8, 3
• Regular skin self-examination should be performed 3

Treatments to Avoid

• Avoid greasy creams for basic care as they may facilitate folliculitis development 1
• Do not use topical acne medications (retinoids) as they worsen sun-induced rash through drying effects 1
• Avoid inadequate topical steroid use without dermatologist supervision due to risk of perioral dermatitis and skin atrophy 1