Evaluating patient responses to omalizumab in solar urticaria

Overexposure to ultraviolet radiation in solar urticaria

A man in his 50s was diagnosed with solar urticaria following monochromated light testing that demonstrated exquisite photosensivity to ultraviolet (UV) A, UV B (UVB) and visible light.Treatment options for this photodermatosis are limited; UVB phototherapy is one modality that can be appropriate in some patients. This is administered at very low doses in a controlled environment to induce skin hardening.1 To self-treat his condition, the patient used a commercial sunbed on two occasions several days apart. He noted an immediate flare of solar urticaria after first use with associated dizziness. Following the second use, he felt generally unwell and was witnessed to lose consciousness and displayed jerky movements of his limbs while a passenger in a car. Investigations including a head MRI and an EEG were normal; an anoxic seizure caused by a flare of solar urticaria was later confirmed.Solar urticaria is a rare photodermatosis that is poorly understood and difficult to treat. The condition has a significant impact on the quality of life of patients. Severe cases can be associated with systemic symptoms that could be life-threatening.

Solar urticaria involves rapid mast cell STAT3 activation and neutrophil recruitment, with FcεRI as an upstream regulator

BACKGROUND

Solar urticaria is a rare photodermatosis characterized by rapid-onset sunlight-induced urticaria, but its pathophysiology is not well understood.

OBJECTIVE

We sought to define cutaneous cellular and molecular events in the evolution of solar urticaria following its initiation by solar-simulated UV radiation (SSR) and compare with healthy controls (HC).

METHODS

Cutaneous biopsy specimens were taken from unexposed skin and skin exposed to a single low (physiologic) dose of SSR at 30 minutes, 3 hours, and 24 hours after exposure in 6 patients with solar urticaria and 6 HC. Biopsy specimens were assessed by immunohistochemistry and bulk RNA-sequencing analysis.

RESULTS

In solar urticaria specimens, there was enrichment of several innate immune pathways, with striking early involvement of neutrophils, which was not observed in HC. Multiple proinflammatory cytokine and chemokine genes were upregulated (including IL20, IL6, and CXCL8) or identified as upstream regulators (including TNF, IL-1β, and IFN-γ). IgE and FcεRI were identified as upstream regulators, and phosphorylated signal transducer and activator of transcription 3 expression in mast cells was increased in solar urticaria at 30 minutes and 3 hours after SSR exposure, suggesting a mechanism of mast cell activation. Clinical resolution of solar urticaria by 24 hours mirrored resolution of inflammatory gene signature profiles. Comparison with available datasets of chronic spontaneous urticaria showed transcriptomic similarities relating to immune activation, but several transcripts were identified solely in solar urticaria, including CXCL8 and CSF2/3.

CONCLUSIONS

Solar urticaria is characterized by rapid signal transducer and activator of transcription 3 activation in mast cells and involvement of multiple chemotactic and innate inflammatory pathways, with FcεRI engagement indicated as an early event.

Lichturtikaria: Klinik, Diagnostik, Verlauf und Therapiemanagement bei 27 Patienten

BACKGROUND AND OBJECTIVES

Solar urticaria is a rare photodermatosis, yet lacking standardization in diagnosis and therapy. The aim of this research was to use innovative radiation sources for diagnostics with defines and reproducible emission spectrum and doses. A uniform therapy step scheme was to be created.

PATIENTS AND METHODS

In a longitudinal study, 27 patients were examined with solar urticaria over 13 years. With a characteristic anamnesis, the diagnosis was confirmed with phototesting from various radiation sources (UVB, UVB311nm, UVA, UVA1, green light, red light) and a therapy step scheme consisting of light protection, antihistamines, rush hardening with UVA-1 and the treatment with omalizumab.

RESULTS

Action spectrum: UVB 44 %, UVA 70 %, UVA1 89 %, green light 37 % and red light 22 %. Rush hardening was performed on 20 patients, 17 of whom were adequately protected. In three further patients, omalizumab was additionally treated in off-label use.

CONCLUSIONS

Photoprovocation with UVB, UVB311nm, UVA, UVA-1 and visible light with innovative radiation sources is uniformly possible in every major skin clinic. With the help of the therapy step scheme the patients can be adjusted well, a Rush Hardening with UVA-1 is a safe method to help the patients during the sunny season. Omalizumab as the last therapy option is effective, but currently only possible in off-label use.

Solar urticaria: Clinic, diagnostic, course and therapy management in 27 patients

BACKGROUND AND OBJECTIVES

Solar urticaria is a rare photodermatosis, the diagnosis and therapy of which have not yet been standardized. The aim of this research was to use innovative radiation sources for diagnostics with defined and reproducible emission spectra and doses. A uniform therapy step scheme was to be created.

PATIENTS AND METHODS

In a longitudinal study, 27 patients with solar urticaria were examined over 13 years. With a characteristic anamnesis, the diagnosis was confirmed with phototesting (photoprovocation) from various radiation sources (UVB, UVB311nm, UVA, UVA-1, green light, red light) and a therapy step scheme was designed consisting of light protection, antihistamines, rush hardening with UVA-1, and administration of omalizumab.

RESULTS

Action spectrum: UVB 44 %, UVA 70 %, UVA-1 89 %, green light 37 % and red light 22 %. Rush hardening with subsequent maintenance therapy was performed on 20 patients, 17 of whom were hereby adequately protected. In three further patients, omalizumab was additionally administered.

CONCLUSIONS

Phototesting with UVB, UVB311nm, UVA, UVA-1, and visible light with innovative radiation sources is uniformly possible in every major skin clinic. With the help of the therapy step scheme the patients can be adjusted well. Rush hardening with UVA-1 is a safe method to help the patients during the sunny season. Omalizumab as the last therapy option is effective, but currently only possible in off-label use.

Phototherapy in the Evaluation and Management of Photodermatoses

Ultraviolet light (UV) and visible light are important components in the diagnosis of photodermatoses, and UV has the unique ability to also be used to manage photodermatoses. Phototesting, provocative light testing, and photopatch testing can provide important information in diagnosing patients with photodermatoses; phototesting can be used to determine the starting dose for phototherapy in these patients. Once photosensitivity is established, narrowband UVB and UVA1 therapy have helped to improve the quality of life of photosensitive patients, such as those with polymorphous light eruption, chronic actinic dermatitis, and solar urticaria.