Topical Corticosteroid Selection for Polymorphic Light Eruption Based on Severity
For mild to moderate polymorphic light eruption (PLE), use potent topical corticosteroids (betamethasone or hydrocortisone butyrate) on the trunk and low-potency hydrocortisone 1% on the face, applied immediately after UV exposure or at the first sign of eruption. 1
Severity-Based Topical Steroid Algorithm
Mild PLE (Limited body surface area, minimal symptoms)
- Facial involvement: Apply hydrocortisone 1% once to twice daily 1, 2
- Trunk/extremities: Apply hydrocortisone 2.5% or desonide 0.05% once to twice daily 2
- Duration: Continue until lesions resolve, typically within 3-7 days 3
Moderate PLE (Extensive involvement, significant pruritus)
- Facial involvement: Apply hydrocortisone 1% twice daily 1, 2
- Trunk/extremities: Apply betamethasone (potent corticosteroid) or hydrocortisone butyrate immediately after UV exposure 1
- Prophylactic use: When undergoing phototherapy desensitization, apply potent topical steroid after each exposure to prevent provocation 1
- Duration: Continue for 5-7 days or until complete resolution 3, 4
Severe PLE (Widespread eruption, intense symptoms, phototherapy-induced provocation)
- Facial involvement: Hydrocortisone 1% twice daily 1
- Trunk/extremities: Potent topical corticosteroids (betamethasone or hydrocortisone butyrate) applied immediately after each phototherapy session for the first 6 exposures 1
- Adjunctive therapy: Consider adding oral prednisolone 40-50 mg for the first 2 weeks when initiating phototherapy to prevent severe provocation 1
- Alternative for acute flares: Short-course oral prednisolone (moderate dose) from earliest onset clears itch in mean 2.8 days and rash in 4.2 days 5
Critical Implementation Points
Anatomic site determines potency selection: The face requires low-potency agents (hydrocortisone 1%) due to increased risk of atrophy, telangiectasias, and rosacea-like eruptions with higher potency steroids 1, 2. The trunk tolerates potent corticosteroids (betamethasone, hydrocortisone butyrate) without significant adverse effects 1.
Timing of application matters: When used prophylactically during phototherapy desensitization, apply topical corticosteroids immediately after UV exposure rather than before, as this reduces provocation rates from 48-62% with UVB alone to more manageable levels 1.
Provocation management: If PLE is provoked during phototherapy (occurs in 12-50% of PUVA courses), manage with potent topical steroids, lower subsequent dose increments, and omit 1-2 treatments if particularly severe 1.
Common Pitfalls to Avoid
- Avoid moderate-to-ultra-high potency steroids (Class I-V) on the face: These increase risk of atrophy, striae, and telangiectasias 2
- Don't delay treatment: Oral prednisolone is most effective when started at the earliest sign of eruption, with efficacy declining if delayed beyond 48 hours 5
- Don't use topical steroids alone for severe cases: Combine with oral corticosteroids or phototherapy desensitization for refractory disease 1, 6