Dermatology: Practical and Conceptual Research Letter | Dermatol Pract Concept. 2025;15(4):6693 1 Photodynamic Therapy with 5-Aminolevulinic Acid for Cosmetic-Induced Acne Fulminans: Case Report and Literature Review Ran An1, Rui Liu1, Hui Gu1 1 Department of Dermatology, The People’s Hospital of Jianshui, Jianshui, Yunnan, China Key words: Acne Fulminans, Photodynamic Therapy, 5-Aminolevulinic Acid, Supramolecular Salicylic Acid, Cosmetic-Induced Reactions Citation: An R, Liu R, Gu H. Photodynamic Therapy with 5-Aminolevulinic Acid for Cosmetic-Induced Acne Fulminans: Case Report and Literature Review. Dermatol Pract Concept. 2025;15(4):6693. DOI: https://doi.org/10.5826/dpc.1504a6693 Accepted: August 26, 2025; Published: October 2025 Copyright: ©2025 An et al. This is an open-access article distributed under the terms of the Creative Commons Attribution- NonCommercial License (BY-NC-4.0), https://creativecommons.org/licenses/by-nc/4.0/, which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original authors and source are credited. Funding: This work was supported by the Beijing Medical Award Foundation, 7th Round of the “Rui-Ying” Scientific Research Fund. Competing Interests: None. Authorship: All authors have contributed significantly to this publication. Corresponding Author: Rui Liu, MD, Department of Dermatology, The People’s Hospital of Jianshui, Jianshui, Yunnan 654399, China. E-mail: ar506529014@outlook.com Introduction Acne fulminans (AF) is a rare, explosive variant of inflam- matory acne marked by rapidly progressing nodulocystic lesions, hemorrhagic crusts, and systemic symptoms. Stan- dard therapy combines oral corticosteroids with isotretinoin, but teratogenic risk and systemic adverse effects may limit acceptance among females of reproductive age [1,2]. We re- port a non-systemic regimen—5-aminolevulinic acid photo- dynamic therapy (ALA-PDT) plus supramolecular salicylic acid (SSA)—for AF occurring after use of a non-compliant cosmetic product, with positive patch-test reactivity to the product. Case Presentation A 25-year-old female with a history of acne developed in- tense facial burning and erythema shortly after using a non-compliant “whitening and anti-acne” cosmetic. Within three days she had extensive inflammatory papules, pus- tules, hemorrhagic nodules, and purulent crusts on both cheeks and the jawline, with fatigue, fever (38.5° C), and elevated inflammatory markers (WBC, CRP, ESR), consis- tent with acne fulminans. She declined systemic steroids and isotretinoin because of concerns about adverse effects and teratogenicity. Standardized closed patch testing with the pa- tient’s product (neat and 1:10 in petrolatum; 48-h occlusion) yielded positive (++) reactions at 48/72 h, while petrolatum and blank controls were negative. VISIA® imaging showed diffuse inflammatory erythema with telangiectatic dilation in the same regions, and dermoscopy at the test site revealed diffuse background erythema with scattered dotted and short linear vessels (Figures 1A–E). Because she declined systemic therapy, we initiated weekly ALA-PDT plus 30% supramolecular salicylic acid (SSA) for four sessions. Each visit included gentle cleansing, a 3-minute application of 30% SSA (controlled-release) to affected areas, removal with a mild cleanser, application of 2 Research Letter | Dermatol Pract Concept. 2025;15(4):6693 Figure 1. (A–C) VISIA® skin analysis of the cheek demonstrates pronounced, diffuse inflammatory erythema with noticeable capillary/telangiectatic dilation in the same area. (D) At 72 h after standardized closed patch testing with the patient’s non-compliant cosmetic product, the left cheek test site showed erythema, infiltration/induration, papules, and small vesicles with marked pruritus, whereas the contralateral right cheek control (petrolatum vehicle) showed no reaction. (E) Dermoscopy of the test site revealed diffuse background erythema with scattered dotted and short linear vessels. 5% ALA cream under sterile gauze occlusion for 30 minutes, and illumination with 635 nm LED at 50 mW/cm² to a total fluence of 150 J/cm². After one session, most hemorrhagic/ purulent crusts and suppurative nodulocystic lesions had subsided. By the fourth session, inflammatory papules had improved by approximately 80%, with marked reductions in pain, erythema, and swelling; only mild atrophic scarring persisted. No notable adverse event occurred, and no recur- rence was observed on follow-up (Figures 2A–F). Conclusion This case highlights AF—occurring after exposure to a non-compliant cosmetic product with positive patch-test reactivity—successfully managed without systemic agents using ALA-PDT plus SSA. Published evidence on ALA-PDT for AF remains scarce but includes two case-level reports describing rapid clinical improvement and good tolerabil- ity, despite heterogeneous parameters and use as mono- or adjunct therapy [4,6] (Table 1). Mechanistically, ALA-PDT promotes intrafollicular protoporphyrin IX accumulation and reactive oxygen species formation, reducing Cutibac- terium acnes, modulating inflammation, and attenuating sebaceous activity [3,4], while SSA provides keratolysis and additional anti-inflammatory effects that relieve fol- licular occlusion and may aid barrier recovery [5]. For reproductive-age patients who decline or cannot tolerate systemic therapy, this topical/physical combination may of- fer rapid disease control with favorable tolerability. Larger series are warranted to confirm efficacy, refine parameters (photosensitizer concentration, occlusion time, fluence, ses- sion number), and define its role within stepwise AF man- agement alongside careful identification and avoidance of potential external triggers. Research Letter | Dermatol Pract Concept. 2025;15(4):6693 3 Figure 2. (A–C). The cheeks exhibit extensive hemorrhagic and purulent crusts covering coalescent suppu- rative nodulocystic lesions. (D–F) After a single session of photodynamic therapy combined with supra- molecular salicylic acid, most hemorrhagic and purulent crusts as well as purulent nodulocystic lesions had subsided. (G–I) Following four sessions, the majority of inflammatory papules resolved, with no recurrence observed during follow-up. Table 1. 5-ALA Photodynamic Therapy in Acne Fulminans: Summary of Published Cases and the Present Case. Author (Year) Age/Sex PDT Parameters Adjunct Therapy Outcome (Follow-up) Hao & Wang, 2020, China 23 M 20 % ALA, 3 h occlusion; red-light LED (wavelength NR); 2 sessions Oral isotretinoin 0.5 mg/kg/d Complete remission after 2 sessions; no relapse at 6 months Picone et al., 2022, Italy 18 M ALA conc. NR, 3 h; red-light LED 630 nm; 3 weekly sessions None reported Complete clearance; scar remodeling at 2 months 4 Research Letter | Dermatol Pract Concept. 2025;15(4):6693 Patient Consent: The authors have obtained the consent of the patient for clinical images. Data Availability: Data will be made available on request. References 1. Gutiérrez-Meré R, Tajes I, Diéguez P, et al. Acne fulminans: a narrative review. Actas Dermosifiliogr. 2023;114(9):763-771. DOI:10.1016/j.ad.2023.05.018. PMID: 37506824 2. Trave I, Donadoni R, Cozzani E, et al. Acne fulminans and its multiple associated factors: a systematic review. Eur J Derma- tol. 2023;33(6):624-634. DOI:10.1684/ejd.2023.4629. PMID: 38465543 3. Tewari KM, Dondi R, Yaghini E, et al. Peptide-targeted dendrimeric prodrugs of 5-aminolevulinic acid: enhanced protoporphyrin IX accumulation for photodynamic ther- apy. Bioorg Chem. 2021;109:104667. DOI:10.1016/j.bioorg .2021.104667. PMID:38465543 4. Picone V, Potestio L, Fabbrocini G, Monfrecola G, Marasca C. A case of acne fulminans successfully treated with photodynamic therapy. Photodermatol Photoimmunol Photomed. 2022;38(4): 401-403. DOI:10.1111/phpp.12761. PMID: 34919759 5. Shao X, Chen Y, Zhang L, et al. Effect of 30% supramolecu- lar salicylic acid peel on skin microbiota and inflammation in moderate-to-severe acne vulgaris. Dermatol Ther (Heidelb). 2023;13(1):155-168. DOI:10.1007/s13555-022-00844-5. PMID: 34919759 6. Hao J, Wang T. 5-Aminolevulinic acid photodynamic therapy and isotretinoin for treatment of drug-induced acne fulmi- nans in a patient with idiopathic thrombocytopenic purpura. Photodiagn Photodyn Ther. 2020;29:101630. DOI:10.1016 /j.pdpdt.2019.101630. PMID: 31870898