Current treatment practices and efficacy in solar urticaria: insights from a patient survey

Background: Solar urticaria (SolU) is a rare chronic inducible urticaria and photodermatosis, presenting with wheal/flare formation accompanied by severe itch, following exposure to light in the triggering action spectrum. Therapeutic options remain limited for SolU, and the perspective of patients regarding the efficacy of available treatments remains unknown.

Methods: Patients with SolU, organized in a disease-specific Facebook group, were asked to complete an electronic questionnaire on their condition and therapies performed between May 2023 and April 2024. The certainty of SolU diagnosis was differentiated as i) physician confirmed by clinical presentation, ii) light provocation tests, or iii) patient-reported. Study outcomes included clinical presentation, triggering action spectrum, disease severity, impairment of quality of life, therapies performed, and their efficacy. Logistic regression models were used to study the association between clinical factors and treatment outcomes.

Results: A total of 112 patients (female, n = 94; median age, 42 years) participated in the study. Most patients considered their condition severe or extremely severe (n = 72, 76.6%) with a very/extremely impacted quality of life (n = 82, 86.3%). The majority of patients received non-sedating antihistamines (58.9%, n = 66), leading to worsening, no change, or only slight improvement in most cases (82.2%, n = 53). Omalizumab was given to 28 patients and induced complete control in 32.1% of cases. Treatments with sedating antihistamines, ciclosporin, systemic corticosteroids, phototherapy, and Polypodium leucotomos were performed in a residual number of patients and did not lead to a substantial improvement of the symptoms. Antihistamines were more effective in patients with mild disease, whereas omalizumab maintained a positive response across different disease severity levels.

Conclusion: SolU is generally perceived as severe by affected patients, leading to a high impairment of quality of life. Performed therapies, including off-label treatments, are not sufficient to reach complete remission of symptoms in the majority of patients. Effective therapeutics for SolU are urgently needed to achieve better care for this highly burdened patient population.

Introduction

Solar urticaria (SolU) is a rare chronic inducible urticaria and photodermatosis with transient lesions induced by components of solar radiation, such as UVA, UVB, or visible light, but also by artificial light sources (1, 2). According to estimations, SolU accounts for less than 0.5% of chronic urticaria cases and 0.7% to 3.2% of all photodermatoses (3). People of all skin types can be affected, and it occurs more frequently in women, with peak presentation at approximately 35 years of age (4). Clinically, burning, itching, erythema, and whealing develop within 5–10 minutes after sun exposure in most patients. SolU is associated with a high disease burden, severely impacting the quality of affected patients (5, 6) due to both the symptoms of the disease and avoidance behaviors (4). Challenge tests are performed using narrowband and broadband irradiation sources, with methodology and availability varying between centers. Photoprovocation enables the confirmation of the diagnosis and the evaluation of minimal urticarial doses (MUDs), which additionally inform SolU severity and action spectrum (4).

Current guidelines recommend the use of a non-sedating antihistamine (nsAH) for the treatment of SolU (7). In general, antihistamines are observed to have variable clinical effects, with a proportion of patients being refractory to single doses and a fourfold dose of these drugs (8). The monoclonal IgE antibody, omalizumab, which prevents the binding of IgE antibodies to the mast cell Fc_ϵRI receptor, is reported to induce therapeutic relief in a subset of SolU patients (9–11). The efficacy of omalizumab in SolU and other chronic inducible urticarias is further supported by real-world data (12–15). However, in a phase II open-label study including 10 SolU patients refractory to antihistamines, omalizumab (300 mg/4 weeks) failed to demonstrate efficacy and a substantive increase in MUD (16). Other therapeutic approaches include inducing tolerance by repetitive exposure to increasing doses of UV radiation, as in phototherapy hardening (17), or promoting melanization through treatment with afamelanotide (18). Intravenous immunoglobulins have been considered as a treatment option for SolU but have not yet shown sufficient efficacy (19), while a study suggests that Polypodium leucotomos (PL), as a natural treatment option, can reduce skin reactions in SolU (20).

This study was designed as an online survey with the aim of assessing disease characteristics and current treatment practices, as well as the patients’ perspective on the efficacy of available treatment options in SolU. This will help to better understand the disease and its impact on patients’ quality of life, which therapies work best in a real-world setting, and ultimately improve the care of patients with SolU.

Methods

Study population

This was a survey-based study conducted between May 2023 and April 2024. A survey was distributed via the social media platform Facebook within a SolU patient group, and all patients with SolU, diagnosed i) by a physician clinically, ii) by photoprovocation, or iii) per self-report, were included in this survey study. There was no age restriction to participate in the survey. Participation was voluntary, and informed consent was obtained electronically prior to the initiation of the survey (see complete survey in the Supplementary Material). For underage participants, signed informed consent was provided by their legal guardian. This study was approved by the local ethics committee (Charité – Universitätsmedizin Berlin, EA1/167/22). All study procedures were performed according to the Declaration of Helsinki and later revisions.

Study design and outcomes

The survey consisted of 36 questions and additional optional questions depending on the received treatments. It was available in German, English, and Spanish. SoCi-Survey was used to develop the online survey (https://www.soscisurvey.de). Patients’ responses to the online survey were automatically stored in a secure database. Participants could skip any questions they felt uncomfortable answering, and the survey was designed to take approximately 10–15 minutes to complete. No identifiable personal information was collected, ensuring participant anonymity throughout the process.

The questionnaire enquired about demographics (age and sex), clinical characteristics (time to diagnosis, action spectrum, overall disease severity, and disease severity at its worst), disease burden (overall impact on quality of life and impact at its worst), and performed therapies (sedating antihistamines, nsAH, omalizumab, ciclosporin, systemic corticosteroids, phototherapy, PL, and other treatment modalities) and their efficacy using a 6-point Likert scale (complete control, significant improvement, moderate improvement, slight improvement, no change, and worsening). When patients received more than one dosage of one particular drug, the effect of the higher dose was considered for analysis.

Statistical analysis

Statistical analysis was performed using R (version 4.3.2), which provides a robust framework for examining demographic and clinical characteristics. Descriptive statistics were used to analyze the survey data. Categorical data, such as demographic characteristics (e.g., sex and age), and responses related to the action spectrum of SolU were summarized as frequencies and percentages. Continuous data, such as age or time to diagnosis, were summarized using median and range. To investigate the relationships between the studied variables, such as disease severity, quality of life, and time to diagnosis, a correlation analysis using Spearman’s rank correlation coefficient and Kendall’s tau was performed. Additionally, we investigated the association between demographic and clinical factors and the probability of a positive treatment response to nsAH and omalizumab using logistic regression models. A successful treatment was considered when patients evaluated their treatment response as achieving “moderate improvement”, “significant improvement”, or “complete control”; treatments leading to a “slight improvement”, “no change”, or “worsening” were deemed unsuccessful. The statistical significance was set at p < 0.05.

Results

Demographics

A total of 112 patients completed the online survey. Most respondents were female [female, n = 94 (83.9%); male, n = 12 (10.7%); unknown, n = 6 (5.4%)], and the median age was 42 years (range, 10–68; n = 104; Table 1).

Table 1

Table 1. Demographic and clinical characteristics of the study population (n = 112).

Clinical characteristics

A total of 37.7% (n = 20) of patients were diagnosed within the first year after symptom onset, whereas 62.3% (n = 33) received their diagnosis more than 1 year after symptoms began. Most frequently, the diagnosis was made by a physician according to the clinical presentation (45.5%, n = 50). Light provocation testing was performed in 38.2% (n = 42) of cases, while in 18 patients (16.4%), the diagnosis was self-reported without definitive confirmation. Most patients (85.6%, n = 89) reported a time to reaction up to 10 minutes, and 7.7% (n = 8) reported a reaction time over 20 minutes. In total, 56.3% (n = 63) of respondents stated that they knew their action spectrum, with 40 patients indicating that multiple wavelengths triggered their urticaria. Among these, 68.3% (n = 43) reported reacting to UVA, 65.1% (n = 41) to UVB, 41.3% (n = 26) to visible light, 4.8% (n = 3) to infrared, and 7.9% (n = 5) to other not specified light sources (Table 1).

Disease burden

Most patients considered their disease as severe or extremely severe (76.6%, n = 72). In contrast, only two patients reported extremely mild symptoms (2.1%), with the diagnosis in these two cases being confirmed by a physician but not assessed by photoprovocation. Overall, the impact of SolU on quality of life was considered very strong or extremely strong by the majority of patients (86.3%, n = 82), with even higher impact at peak disease severity (Table 1). We recorded a significant moderate correlation between the impact on quality of life and perceived symptom severity (r = 0.46, p < 0.001, Spearman) and a weak correlation with time to diagnose (r = 0.23, p = 0.043, Kendall’s tau).

Treatment

Most patients were treated with nsAH (58.9%, n = 66), with worsening, no improvement, or only slight improvement in most cases (82.2%, n = 53; two missing cases). Omalizumab was given to 25% (n = 28) of patients, with the majority (n = 20) receiving the standard dose of 300 mg/4 weeks. Five patients were treated with an increased dose (>300 mg/4 weeks), while one received 150 mg/4 weeks. Two patients underwent two different drug regimens: 150 mg and 300 mg/4 weeks. Omalizumab induced complete control in 32.1% (n = 9) of cases and significant or moderate improvement in a further 28.6%. Other treatment modalities, including sedating antihistamines, ciclosporin, systemic corticosteroids, phototherapy, and PL, were performed in a residual number of patients and, in general, did not lead to a substantial improvement of symptoms (Table 2, Figure 1).

Table 2

Table 2. Summary of treatment efficacy.

Figure 1

Figure 1. Response to therapy. Forrest plot showing the response to various treatment modalities as assessed by patients (complete control, significant improvement, moderate improvement, slight improvement, no change, and worsening). Black squares represent mean values, and whiskers indicate the 10th and 90th percentiles.

Logistic regressions revealed an association of an unknown action spectrum and a diagnosis based on clinical evaluation (without photoprovocation) with a poor treatment response to nsAH (Table 3). As for omalizumab, there was no statistically significant association between clinical and demographic factors and therapy response (Table 4). Antihistamines seemed to be more effective in patients with mild disease, as patients with mild disease had a higher probability (72.1%) of having a positive treatment response to nsAH compared to those with a severe condition (3.5%). As for omalizumab, the likelihood of a positive response was maintained across severity levels. Moreover, patients diagnosed solely on clinical symptoms had a lower response probability to nsAH (19.2%), but not to omalizumab.

Table 3

Table 3. Logistic regression analysis evaluating the association between demographic and clinical factors with the treatment efficacy of non-sedating antihistamines.

Table 4

Table 4. Logistic regression analysis evaluating the association between demographic and clinical factors with the treatment efficacy of omalizumab.

Discussion

Patients with SolU generally perceive their condition as severe, with a substantial impact on quality of life. Most patients are treated with antihistamines, which, however, show an insufficient effect in most cases. Omalizumab seems to be more effective, but it is not approved for the treatment of SolU and, thus, is only accessible for a subset of patients as an off-label therapy.

Most study participants were diagnosed based on clinical symptoms, and only a subset of patients underwent light provocation testing. These findings outline the discrepancy in diagnostic work-up across clinical centers and may reflect the lack of photoprovocation devices in non-specialized centers. As a result, a substantial proportion of patients (44%) reported not knowing their action spectrum, potentially affecting their understanding of their triggering factors and their quality of life. This suggests a need to better standardize the diagnostic work-up in SolU, including the implementation of photoprovocation. Moreover, most patients experienced a diagnostic delay of over 1 year after the onset of symptoms. This delay may result from a lack of awareness of SolU in routine dermatological and allergy clinics, the time taken for general practitioners to refer to a dermatology center, and limitations in access to specialized centers. Furthermore, patients experience their symptoms mostly during spring and summer, so there may be a seasonal delay.

Most SolU patients rated their symptoms as severe and the impact of their disease on their quality of life as very high, consistent with reports of previous observations from photodermatology units (4–6). Our study revealed, as expected, a significant positive correlation between disease severity and the impact on quality of life (r = 0.46, p < 0.001), suggesting an association between these two parameters. Other factors, such as avoidance behaviors with social isolation, visits to doctors’ appointments, and out-of-pocket costs, should also be taken into consideration and assessed, as they may contribute to an impairment in health-related quality of life.

nsAH was the treatment most often offered to patients, showing a broad spectrum of perceived efficacy, with patients reporting both successful and unsuccessful outcomes with these drugs. Omalizumab induced more often complete control of SolU (32.1%) compared to all other treatment modalities. These results support previous studies investigating the effect of omalizumab on different forms of chronic inducible urticaria (especially symptomatic dermographism, cold urticaria, and SolU), in which this biologic drug showed a rapid onset of action with good symptom control in a substantial proportion of patients, but not in all (12–14).

Other treatment modalities were only performed in a small subset of patients, and thus, the results should be regarded with caution. The majority of patients undergoing phototherapy (61.1%, n = 11) experienced a slight to significant improvement of symptoms, while a small number (27.8%, n = 5) reported a worsening of the SolU, which raises concerns about its suitability for some patients. Systemic corticosteroids led to an improvement of the symptoms in most patients, but their long-term use cannot be recommended due to their unfavorable safety profile. The natural treatment alternative PL may be considered in SolU, as it seemed to improve the condition in some patients.

Notably, our findings indicate that therapeutic response to nsAH is associated with disease severity, whereas omalizumab efficacy remains consistent across severity levels, although in a relatively small percentage of patients, suggesting a relevant role of IgE-dependent mechanisms in the pathophysiology of a subset of SolU (15, 21). Patients with mild disease had a substantially higher probability (72.1%) of responding positively to nsAH, compared to those with severe disease (3.5%). While nsAH may be suitable for patients with mild disease, modern targeted therapies may be needed for more severe cases. Thus, patients with moderate-to-severe disease may require earlier consideration of second-line therapies, such as omalizumab.

Additionally, our analysis showed that patients diagnosed solely based on clinical symptoms had a markedly lower probability (19.2%) of responding to antihistamines. This could indicate that symptom-based diagnosis may encompass a heterogeneous patient population with varying underlying pathophysiology. A comprehensive diagnostic work-up with photoprovocation testing seems to be beneficial for treatment response, as suggested by our data.

Our study has a few limitations. i) The diagnosis of SolU was self-reported through the questionnaire, and the information given was not confirmed by a physician. Notably, only 38.2% of patients reported having the diagnosis confirmed by photoprovocation. ii) The diagnostic uncertainty observed in some patients may impact the analysis of treatment responses. iii) A selection bias cannot be ruled out, as patient groups, where recruitment was performed, may attract more severely affected patients. iv) Only a few male patients were included; however, this largely reflects the sex distribution of SolU, which occurs more frequently in women. Additionally, women may access health-related items on Facebook more often than men. v) Although 63 patients stated that they knew their action spectrum, only 42 underwent light provocation testing, suggesting that the reported action spectrum may be unreliable. vi) No validated patient-reported outcome measures assessing disease severity or quality of life were used. Instead, we chose single Likert scale questions to evaluate these parameters, keep the questionnaire short, and reduce the number of potential dropouts. vii) Although the sample size was large, considering that SolU is a rare disease, our study was underpowered for sub-analysis (particularly for treatments other than antihistamines and omalizumab, and for logistic regression models). viii) The survey questionnaire and its translations have not been validated.

To address these issues, future studies should enroll patients with a confirmed diagnosis of SolU by photoprovocation, including the determination of the triggering wavelengths. These studies should use validated patient-reported outcome measures, such as the Urticaria Control Test, the Dermatology Life Quality Index, or the Skindex-29. A multicentric approach is likely needed to achieve a sufficient sample size for adequately powered analysis.

Overall, SolU is perceived as severe by the majority of patients, leading to a high impairment of health-related quality of life. Diagnostic light provocation is only performed in a limited number of patients. In real-life settings, the therapies performed, including off-label treatments, are not sufficient to reach complete remission of symptoms in most patients. Thus, the development of effective therapies and exploration to further personalize therapeutic strategies for SolU patients is of utmost importance to achieve better care for this highly burdened patient population.

Data availability statement

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

Ethics statement

The studies involving humans were approved by Charité–Universitätsmedizin Berlin. The studies were conducted in accordance with the local legislation and institutional requirements. Written informed consent for participation in this study was provided by the participants’ legal guardians/next of kin.

Author contributions

LK: Data curation, Methodology, Investigation, Validation, Visualization, Conceptualization, Project administration, Writing – original draft, Formal Analysis, Writing – review & editing. FA: Validation, Writing – review & editing, Formal Analysis, Visualization. DT: Writing – review & editing, Methodology, Investigation, Conceptualization. AG: Methodology, Writing – review & editing, Conceptualization. MG: Conceptualization, Writing – review & editing, Methodology. AF: Conceptualization, Writing – review & editing, Methodology. EK: Methodology, Conceptualization, Writing – review & editing. KK: Conceptualization, Writing – review & editing, Methodology. SM: Writing – review & editing, Conceptualization, Methodology. HR: Conceptualization, Methodology, Writing – review & editing. KW: Writing – review & editing, Investigation, Conceptualization, Methodology. LR: Writing – review & editing, Conceptualization, Investigation. MP: Supervision, Writing – review & editing, Writing – original draft, Formal Analysis, Project administration, Visualization, Validation.

Funding

The author(s) declare that no financial support was received for the research and/or publication of this article.

Conflict of interest

DT-M has received research funds/was an advisor for Celldex, Moxie, Novartis, and Sanofi outside the submitted work. AG-A is or recently was a speaker and/or advisor for and/or has received research funding from Almirall, Amgen, AstraZeneca, Avene, Blue-Print, Celltrion, Celldex, Escient Pharmaceuticals, Genentech, GSK, Harmonic Bio, Incyte, Instituto Carlos III-FEDER, Jaspers, Leo Pharma, Menarini, Mitsubishi Tanabe Pharma, Noucor, Novartis, Sanofi–Regeneron, Septerna, Servier, Thermo Fisher Scientific, and Uriach Pharma. MG has been a speaker or advisor for AbbVie, Almirall, AstraZeneca, BioCryst, Leo-Pharma, Janssen, Novartis, Pfizer, Sanofi, and Takeda. AF has received fees for manuscript support from Taiho Pharmaceutical; consulting fees from Taiho Pharmaceutical; lecture fees from Sanofi, Kyorin Pharmaceutical, Kaken Pharmaceutical, Novartis, Kyowa Kirin, Mitsubishi Tanabe Pharma, and Taiho Pharmaceutical; and advisory board fees from Taiho Pharmaceutical. EK acted as a speaker for Novartis and Menarini and received funding from Almirall. KK received educational speaker fees from Novartis, Menarini, and Sanofi Genzyme. HR has received institutional sponsorship for research, consultancy, or speaker fees outside the submitted work from Pharming and Novartis Pharma, Sanofi, Third Harmonic Bio, AbbVie, and Leo Pharma. KW has support for research projects from Novartis, Sanofi, and Takeda outside the submitted work and personal fees from BioCryst, BioMarin, CSL Behring, Novartis, Moxie, and Takeda outside the submitted work. LR has research collaborations and clinical trials funded by Clinuvel Ltd. and Mitsubishi Tanabe Pharma America, Inc. MP has received research funding from Almirall, Clinuvel, and Pfizer; is a consultant for Almirall, Galderma, Incyte, and Sanofi; is an investigator for Allakos, Celldex Therapeutics, Incyte, Sanofi, and Trevi Therapeutics; and has received speaker honoraria and/or travel fees from AbbVie, Beiersdorf, Celltrion, CSL Behring, Doctorflix, Eli Lilly, Falk Foundation, FomF GmbH, GA2LEN, Galderma, Novartis, P.G. Unna Academy, Sanofi, StreamedUP, TouchMDT, and Zai Lab.

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Supplementary material

The Supplementary Material for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fimmu.2025.1683524/full#supplementary-material

Abbreviations

MUD, minimal urticarial dose; nsAH, non-sedating antihistamine; PL, Polypodium leucotomos; SolU, solar urticaria.

References

1. McSweeney SM, Kloczko E, Chadha M, Sarkany R, Fassihi H, Tziotzios C, et al. Systematic review of the clinical characteristics and natural history of solar urticaria. J Am Acad Dermatol. (2023) 89:138–40. doi: 10.1016/j.jaad.2023.01.039

PubMed Abstract | Crossref Full Text | Google Scholar

2. Munoz M, Kiefer LA, Pereira MP, Bizjak M, and Maurer M. New insights into chronic inducible urticaria. Curr Allergy Asthma Rep. (2024) 24:457–69. doi: 10.1007/s11882-024-01160-y

PubMed Abstract | Crossref Full Text | Google Scholar

3. Hamel R, Mohammad TF, Chahine A, Joselow A, Vick G, Radosta S, et al. Comparison of racial distribution of photodermatoses in USA academic dermatology clinics: A multicenter retrospective analysis of 1080 patients over a 10-year period. Photodermatol Photoimmunol Photomed. (2020) 36:233–40. doi: 10.1111/phpp.12543

PubMed Abstract | Crossref Full Text | Google Scholar

4. Haylett AK, Koumaki D, and Rhodes LE. Solar urticaria in 145 patients: Assessment of action spectra and impact on quality of life in adults and children. Photodermatol Photoimmunol Photomed. (2018) 34:262–8. doi: 10.1111/phpp.12385

PubMed Abstract | Crossref Full Text | Google Scholar

5. Rizwan M, Reddick CL, Bundy C, Unsworth R, Richards HL, and Rhodes LE. Photodermatoses: environmentally induced conditions with high psychological impact. Photochem Photobiol Sci. (2013) 12:182–9. doi: 10.1039/c2pp25177a

PubMed Abstract | Crossref Full Text | Google Scholar

6. Jong CT, Finlay AY, Pearse AD, Kerr AC, Ferguson J, Benton EC, et al. The quality of life of 790 patients with photodermatoses. Br J Dermatol. (2008) 159:192–7. doi: 10.1111/j.1365-2133.2008.08581.x

PubMed Abstract | Crossref Full Text | Google Scholar

7. Zuberbier T, Abdul Latiff AH, Abuzakouk M, Aquilina S, Asero R, Baker D, et al. The international EAACI/GA(2)LEN/EuroGuiDerm/APAAACI guideline for the definition, classification, diagnosis, and management of urticaria. Allergy. (2022) 77:734–66. doi: 10.1111/all.15090

PubMed Abstract | Crossref Full Text | Google Scholar

8. Snast I, Lapidoth M, Uvaidov V, Enk CD, Mazor S, Hodak E, et al. Real-life experience in the treatment of solar urticaria: retrospective cohort study. Clin Exp Dermatol. (2019) 44:e164–e70. doi: 10.1111/ced.13960

PubMed Abstract | Crossref Full Text | Google Scholar

9. Maurer M, Zuberbier T, and Metz M. The classification, pathogenesis, diagnostic workup, and management of urticaria: an update. Handb Exp Pharmacol. (2022) 268:117–33. doi: 10.1007/164_2021_506

PubMed Abstract | Crossref Full Text | Google Scholar

10. Parkin D, Ling TC, Ayer J, Rhodes LE, and Rutter KJ. ‘Omalizumab changed my life’: a patient perspective on solar urticaria. Clin Exp Dermatol. (2024) 49:935–6. doi: 10.1093/ced/llae074

PubMed Abstract | Crossref Full Text | Google Scholar

11. Griffin LL, Haylett AK, and Rhodes LE. Evaluating patient responses to omalizumab in solar urticaria. Photodermatol Photoimmunol Photomed. (2019) 35:57–65. doi: 10.1111/phpp.12434

PubMed Abstract | Crossref Full Text | Google Scholar

12. Maurer M, Metz M, Brehler R, Hillen U, Jakob T, Mahler V, et al. Omalizumab treatment in patients with chronic inducible urticaria: A systematic review of published evidence. J Allergy Clin Immunol. (2018) 141:638–49. doi: 10.1016/j.jaci.2017.06.032

PubMed Abstract | Crossref Full Text | Google Scholar

13. Soegiharto R, Alizadeh Aghdam M, Sorensen JA, van Lindonk E, Bulut Demir F, Mohammad Porras N, et al. Omalizumab is effective and safe in chronic inducible urticaria (CIndU): Real-world data from a large multi-national UCARE study. Allergy. (2025) 80:489–99. doi: 10.1111/all.16334

PubMed Abstract | Crossref Full Text | Google Scholar

14. Exposito-Serrano V, Curto-Barredo L, Aguilera Peiro P, Gomez Armayones S, Serra-Baldrich E, Spertino J, et al. Omalizumab for the treatment of chronic inducible urticaria in 80 patients. Br J Dermatol. (2021) 184:167–8. doi: 10.1111/bjd.19425

PubMed Abstract | Crossref Full Text | Google Scholar

15. Pesque D, Ciudad A, Andrades E, Soto D, Gimeno R, Pujol RM, et al. Solar urticaria: an ambispective study in a long-term follow-up cohort with emphasis on therapeutic predictors and outcomes. Acta Derm Venereol. (2024) 104:adv25576. doi: 10.2340/actadv.v104.25576

PubMed Abstract | Crossref Full Text | Google Scholar

16. Aubin F, Avenel-Audran M, Jeanmougin M, Adamski H, Peyron JL, Marguery MC, et al. Omalizumab in patients with severe and refractory solar urticaria: A phase II multicentric study. J Am Acad Dermatol. (2016) 74:574–5. doi: 10.1016/j.jaad.2015.11.021

PubMed Abstract | Crossref Full Text | Google Scholar

17. Lyons AB, Peacock A, Zubair R, Hamzavi IH, and Lim HW. Successful treatment of solar urticaria with UVA1 hardening in three patients. Photodermatol Photoimmunol Photomed. (2019) 35:193–5. doi: 10.1111/phpp.12447

PubMed Abstract | Crossref Full Text | Google Scholar

18. Haylett AK, Nie Z, Brownrigg M, Taylor R, and Rhodes LE. Systemic photoprotection in solar urticaria with alpha-melanocyte-stimulating hormone analogue [Nle4-D-Phe7]-alpha-MSH. Br J Dermatol. (2011) 164:407–14. doi: 10.1111/j.1365-2133.2010.10104.x

PubMed Abstract | Crossref Full Text | Google Scholar

19. Aubin F, Porcher R, Jeanmougin M, Leonard F, Bedane C, Moreau A, et al. Severe and refractory solar urticaria treated with intravenous immunoglobulins: a phase II multicenter study. J Am Acad Dermatol. (2014) 71:948–53.e1. doi: 10.1016/j.jaad.2014.07.023

PubMed Abstract | Crossref Full Text | Google Scholar

20. Caccialanza M, Recalcati S, and Piccinno R. Oral polypodium leucotomos extract photoprotective activity in 57 patients with idiopathic photodermatoses. G Ital Dermatol Venereol. (2011) 146:85–7.

PubMed Abstract | Google Scholar

21. McSweeney SM, Sarkany R, Fassihi H, Tziotzios C, and McGrath JA. Pathogenesis of solar urticaria: Classic perspectives and emerging concepts. Exp Dermatol. (2022) 31:586–93. doi: 10.1111/exd.14493

PubMed Abstract | Crossref Full Text | Google Scholar