Hemoporfin Photodynamic Therapy for a Case of Unilateral Nevoid Telangiectasia

Unilateral nevoid telangiectasia (UNT) is a rare skin condition where tiny, dilated blood vessels cluster in a one-sided, linear pattern—either present at birth or developing later in life. For most patients, the goal of treatment is cosmetic improvement, and pulsed-dye laser (PDL) therapy has long been the standard. But what happens when PDL doesn’t work? A 2021 study in the Chinese Medical Journal shares how hemoporfin-mediated photodynamic therapy (HMME-PDT) helped an 8-year-old boy with PDL-resistant UNT, offering new insights for hard-to-treat cases.

What Is Unilateral Nevoid Telangiectasia?

UNT causes red, thread-like veins (telangiectasia) to form on one side of the body—most often on the face, neck, or upper torso, though lower limb cases are extremely rare (fewer than a dozen reported globally). While some researchers link UNT to high estrogen levels (e.g., during pregnancy or puberty), many patients have normal hormone levels. For these individuals, treatment focuses on reducing the visible blood vessels.

The Case: An 8-Year-Old with PDL-Resistant UNT

The patient, an 8-year-old boy, had a 4-year history of progressive red patches on his left lower leg. The lesions started as a fingertip-sized spot on his leg’s extensor side and gradually spread to his entire left lower extremity, buttock, and back. Diascopy (pressing a glass slide on the skin) made the redness disappear—an indicator of dilated blood vessels.

He’d tried two sessions of 585 nm PDL therapy with no improvement. Tests ruled out liver disease, hormonal imbalances, and other underlying conditions. A skin biopsy confirmed UNT: dilated capillaries in the upper dermis, with no excess mast cells (ruling out similar conditions like telangiectasia macularis eruptiva perstans) or thickened vessel walls (unlike angioma serpiginosum). The biopsy also found vascular endothelial growth factor (VEGF)—a protein that promotes blood vessel growth—on the deformed vessels, but no estrogen or progesterone receptors.

HMME-PDT: A New Approach for Resistant Cases

After obtaining parental consent, the team treated the boy with HMME-PDT—a therapy approved in China for port-wine stains (PWS) since 2016. Here’s how it worked:

Photosensitizer Infusion: The boy received an intravenous dose of hemoporfin (5 mg/kg), a drug that accumulates in abnormal blood vessel cells.
Light Irradiation: Thirty minutes later, doctors used 532 nm LED green light (90 mW/cm² power density) to activate the drug—targeting two areas (a 10 cm spot on his shank and 4.5 cm spot on his thigh) for 20 minutes each.

Three months later, the lesions had significantly improved. For the second session, the boy’s parents requested a larger treatment area to reduce costs. Under close monitoring, two light devices were used simultaneously.

Results: After two sessions, >85% of the lesions were gone—with only mild, temporary skin darkening (hyperpigmentation). Blood tests (routine, coagulation, liver/kidney function) remained normal, and there was no recurrence in 14 months of follow-up. Dermoscopy (a skin microscope) confirmed fewer dilated, branched vessels.

Why HMME-PDT Works When PDL Doesn’t

PDL uses yellow light (585/595 nm) to target hemoglobin in blood vessels, but it has key limitations:

Melanin Competition: Skin pigment (melanin) absorbs the same light, reducing effectiveness.
Vessel Size: PDL only treats vessels 50–150 µm wide—too small for larger, branched vessels like the boy’s.
Pattern Sensitivity: It works well on dotted/globular veins but not on the reticulated (net-like) vessels seen in UNT.
Recurrence: A 1999 study in Journal of Cutaneous Laser Therapy found PDL-treated UNT often returns.

HMME-PDT overcomes these issues by using photochemical and photothermal reactions to destroy abnormal vessels:

The drug (hemoporfin) builds up in endothelial cells (vessel linings) but not in healthy skin.
When activated by green light, it produces singlet oxygen—a toxic molecule that damages vessel walls, triggers blood clots, and closes off abnormal capillaries.
It targets any vessel size and penetrates deeper than PDL, making it effective for large, branched veins.

The boy’s VEGF-positive vessels also help explain why HMME-PDT worked: research in Lasers in Medical Science shows HMME-PDT reduces VEGF levels, slowing blood vessel growth and preventing recurrence.

What This Means for UNT Patients

This case highlights HMME-PDT as a safe, effective option for PDL-resistant UNT—especially for patients with large, branched vessels. While HMME-PDT requires avoiding strong sunlight for 2 weeks post-treatment (to prevent skin sensitivity) and multiple sessions for large areas, the results are promising.

The study’s authors—Jie Kang (Department of Dermatology, Union Hospital, Fujian Medical University), Han-Jin Xie (Department of Dermatology, People’s Hospital, Fujian University of Traditional Chinese Medicine), and colleagues—stress that more research is needed to confirm long-term efficacy. But for families like this boy’s, it’s a critical step forward.

References

Kang J, Xie HJ, Lin YY, Lin LH, Xiao XM. Hemoporfin photodynamic therapy for a case of unilateral nevoid telangiectasia. Chinese Medical Journal. 2021;134(10):1245–1247. doi.org/10.1097/CM9.0000000000001335
Kawakami T, Kimura S, Soma Y. Unilateral nevoid telangiectasia on the lower extremity of a pediatric patient. Journal of the American Academy of Dermatology. 2010;62:528–530. doi.org/10.1016/j.jaad.2009.02.030
Sharma VK, Khandpur S. Unilateral nevoid telangiectasia – Response to pulsed dye laser. International Journal of Dermatology. 2006;45:960–964. doi.org/10.1111/j.1365-4632.2006.02862.x
Cliff S, Harland CC. Recurrence of unilateral naevoid telangiectatic syndrome following treatment with the pulsed dye laser. Journal of Cutaneous Laser Therapy. 1999;1:105–157. doi.org/10.1080/14628839950516940
Ma J, Lai G, Lu Z. Effect of 410 nm photodynamic therapy with hemoporfin on the expression of vascular endothelial growth factor (VEGF) in cultured human vascular endothelial cells. Lasers in Medical Science. 2019;34:149–155. doi.org/10.1007/s10103-018-2649-8

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