Polymorphic light eruption
ICD-10 L56.4 · ICD-11 EJ30.0

Managing Polymorphic Light Eruption When Prednisolone and Phototherapy Have Not Worked

Clinical scenario

This protocol applies to patients with polymorphic light eruption (PLE) who have not achieved adequate control on second-line therapy — specifically when neither a short oral corticosteroid course nor desensitization phototherapy has delivered the expected clinical benefit.

Second-line treatment failure
Prior therapies that did not succeed

The previous line comprised either oral prednisolone or desensitization phototherapy — including narrowband UVB, psoralen plus UVA (PUVA), or broadband UVB. The expected outcomes were settling of itch and rash within 48 hours of starting prednisolone and a meaningful reduction in the frequency and severity of PLE symptoms. When those targets are not reached, escalation is warranted.

Next-line approach

When second-line therapies fail, the protocol moves to third-line systemic immunosuppression. The choice of agent is guided by specific patient-level factors and contraindications — the complete selection criteria, full regimen, and clinical algorithm are available in the structured protocol.

Treatment goal: Increased minimal erythemal responses on phototesting after 3 months.
Instant Access to Structured Evidence-Based Regimens

References

DOI: 10.1034/j.1600-0781.2003.00048.x

The clinical effectiveness of azathioprine in PLE was demonstrated in two patients unresponsive to other treatments, lending support to an underlying immunological basis of the disorder.

Azathioprine may be considered appropriate for patients who are exquisitely sun-sensitive, in whom sunscreens are ineffective and who cannot tolerate phototherapy, but is contraindicated in female patients trying to conceive.

The clinical benefit of cyclosporin in PLE was reported in a patient treated for co-existing psoriasis.

After 3 months, phototesting revealed increased minimal erythemal responses.

View source ↗