Tips for Managing Pain and Local Skin Reactions During Photodynamic Therapy

Setting Patient Expectations

During a recent Dermatology Times Expert Perspectives video series discussion, Neal Bhatia, MD, director of clinical dermatology at Therapeutics Clinical Research in San Diego, California, described his tips for managing pain associated with photodynamic therapy (PDT) treatment. Bhatia authored a paper published in the Journal of Drugs in Dermatology in which he reviewed best practices to minimize pain during PDT with 5-aminolevulinic acid.¹

According to Bhatia, language matters before the first photosensitizer is applied. He recommends reframing how clinicians describe what patients will experience.

"Don't call them side effects, call them anticipated local skin reactions, so the patients are aware things may be coming," Bhatia said.

Pre-treatment preparation begins a few days out. Bhatia starts patients on antihistamines 2 days before the procedure, doses them again the morning of treatment, and continues through 2 days post-procedure. The rationale is mechanistic: mast cell infiltration drives much of the erythema, edema, and pain signaling seen in PDT responses. Slowing mast cell proliferation and degranulation, he notes, can meaningfully reduce patient discomfort without interfering with efficacy. Topical anesthetics such as fluocinolone or low-dose lidocaine preparations may also be used, though Bhatia advises caution with tetracaine given its absorption potential.

In-Room and Post-Procedure Comfort Measures

During treatment, Bhatia emphasizes the value of direct patient engagement. Checking in at minutes 1 and 3, maintaining conversation, and physically staying present all serve as distraction-based pain modulation.

"Talk anesthesia is one of the best pain modulators you can do," he said. "Just start the treatment with them, hold their hand, ask them how they're doing."

A cooling fan overhead and a handheld misting fan positioned beneath the light source provide additional relief. If pain peaks early, Bhatia notes clinicians can pause briefly at 3 minutes without compromising outcomes, as efficacy typically plateaus around the 6-minute mark.

Post-procedure care centers on a thick medicated moisturizing balm, a gentle cleanser, broad-spectrum sunscreen, and adequate hydration. Patients must avoid sun exposure for at least 40 hours following treatment.

Reference

1. Bhatia N. The interventions to minimize pain during photodynamic therapy with 5-aminolevulinic acid for the treatment of cutaneous diseases. J Drugs Dermatol. 2023;22(11):1082-1087. doi:10.36849/JDD.7637

View the full series here.