Severe acne, characterized by cysts and nodules, can significantly impact a patient\'s self-image and quality of life [1]. In China, first-line treatments for severe acne typically include oral isotretinoin, topical benzoyl peroxide, and oral or topical antibiotics [2]. However, due to concerns about safety, oral isotretinoin and antibiotics are not recommended for lactating women, posing challenges in treating acne in this population and often leading to emotional distress. While photodynamic therapy has shown effectiveness in patients unwilling to take oral medications [3], treating severe acne during lactation remains a complex issue with limited research available. In this unique case, fire needle combined with photodynamic therapy was successfully utilized to address severe acne in a lactating patient. Following treatment, the patient experienced clearance of cysts, nodules, and pustules, as well as an improvement in depressive symptoms, yielding significant outcomes. Nevertheless, the efficacy and safety of this combined approach warrant further investigation through clinical trials.

OBJECTIVE: In this study, the therapeutic effect of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) in comparison to blue/red light combined with intralesional triamcinolone injection for severe inflammatory acne was evaluated and analyzed.
METHODS: One hundred and four cases of severe inflammatory acne were analyzed in this study. They were divided into two groups as control and observation groups, 52 cases in each group. The control group (group A) received red and blue light combined with triamcinolone injection and lidocaine injection (1:4), while the observation group (Group B) was treated with ALA-PDT. Finally, the therapeutic effect and the occurrence of adverse reactions were compared between the two groups.
RESULTS: After 2, 4 and 6 weeks, the effectiveness rates of group B was 28.85%, 75.00%, and 86.54%, respectively while it was 9.62%, 51.92%, and 69.23%, respectively in group A. The difference between A and B was statistically remarkable (χ2 = 6.1905, 5.9713, 4.5217, p = 0.0128, 0.0145, 0.0335 at p < 0.05). In addition, the incidence of adverse reactions in B was 5.77%, lower than A (32.69%). This difference between A and B was statistically remarkable (χ2  = 12.1333, p = 0.0005). After 2, 4, and 6 weeks of treatment, the number of residual lesions in the group B group was remarkably lower than group A (p < 0.01). There was remarkable difference in the incidence of pain, burning sensation, pigmentation and erythema between the two groups.
CONCLUSIONS: The therapeutic effect of ALA-PDT in the treatment of severe acne is better than red blue light combined with triamcinolone injection and lidocaine injection. In addition, ALA-PDT has an ideal effect in the treatment of severe acne.

UNASSIGNED: Acne is a chronic inflammatory skin disease that affects the pilosebaceous follicle and is influenced by heredity, hormones, inflammation, and the environment. At present, the recognized pathogenesis mainly includes four categories: excessive sebum secretion, excessive Cutibacterium acnes proliferation, excessive keratinization of sebaceous glands in hair follicles, and inflammatory mechanisms. Previous studies have found that DNA methylation is closely related to some chronic inflammatory skin diseases, and there is evidence that DNA methylation is controlled by genetic factors, making us want to know the relationship between DNA methylation, genetic variation and acne.
UNASSIGNED: In our previous study, we performed genome-wide DNA methylation analysis in peripheral blood samples from 44 patients with severe acne and 44 unaffected normal subjects, and identified 23 differentially methylated probes (DMPs). In this study, we identified single nucleotide polymorphisms (SNPs) associated with severe acne by genome-wide association analysis in these 88 samples. To test the association between SNPs and DMPs, we conducted DNA methylation quantitative trait loci (methQTL) analysis. Next, causal inference testing (CIT) was used to determine whether genetic variation influences DNA methylation, which impacts disease phenotypes.
UNASSIGNED: We found 38,269 SNPs associated with severe acne. By methQTL analysis, we obtained 24 SNP-CpG pairs that reached the threshold (FDR < 0.05), which included 7 unique CpGs and 22 unique methQTL SNPs. After CIT analysis, we found that 11 out of 24 pairs of SNP-CpG showed a weakened SNP effect after adjustment for methylation, indicating a methylation-mediated relationship between SNPs and severe acne. These 11 SNP-CpG pairs consist of four unique CpG sites and 11 SNPs, of which three CpG sites, cg03020863, cg20652636, and cg19964325, are located on the gene body of PDGFD, the intron of SH2D6, and the 5\'UTR of the IL1R1 gene, respectively.
UNASSIGNED: During this study, the DNA methylation of certain genes was found to be influenced by genetic factors and mediated the risk of severe acne in a young Chinese male population, providing a new perspective on the pathogenesis of severe acne.

BACKGROUND: Acne is the eighth-most prevalent inflammatory skin disease with no optimal treatment. Photodynamic therapy (PDT) is an effective treatment for severe acne.
OBJECTIVE: The effect of PDT on the composition and diversity of skin microflora in severe acne patients was studied.
METHODS: A total of 18 patients with severe acne and 8 healthy individuals were selected for this study. Patients were treated with 5-aminolevulinic acid-mediated PDT once a week three times in total; the skin microbiome was measured by 16S ribosomal RNA gene sequencing before and after treatment (1 week after each PDT).
RESULTS: The microflora composition was different between healthy controls and patients, and between patients before and after treatment. Alpha diversity indices were lower in patients than those in control. There were 15 bacterial genera with high relative abundance that had noticeable changes during treatment. At the genus level,particularly Cutibacterium acnes (C. acnes formerly Propionibacterium acnes), there was no statistically significant difference among different group. The abundances of Staphylococcus epidermidis and Staphylococcus aureus were low.
CONCLUSIONS: The microbial composition is different between severe acne patients acne patients and healthy individuals. The therapeutic efficacy of severe acne treated with PDT is associated with the composition and diversity of skin microbiota.
CONCLUSIONS: The skin microbial composition changes after PDT treatment. PDT is an effective method for the treatment of severe acne.

UNASSIGNED: Androgens acting through the androgen receptor play a crucial role in the pathogenesis of acne. This study aimed to identify whether two key genes (CYP21A2 and CYP19A1) involved in the synthesis and metabolism of androgens were associated with Pillsbury III-IV severe acne vulgaris.
UNASSIGNED: We carried out a standard questionnaire survey about acne and enlisted 600 Pillsbury III-IV severe acne vulgaris patients and 652 healthy controls of Han Chinese descent from Yunnan, China in the study. Twenty-two single nucleotide polymorphisms (SNPs) were genotyped by SNaPshot assay and analyzed for association with severe acne.
UNASSIGNED: There was no significant difference in gender between the two groups (P = 0.085), and the age of the acne case group was significantly lower than that of the control group (P < 0.001). Our results revealed that only two SNPs, rs6474 (p.Arg102Lys) (P = 0.001) and rs6465 (P = 0.025) of the CYP21A2 gene were significantly associated with severe acne among the Han Chinese. When subjects were divided into males and females, significant associations were observed only in male patients with severe acne vulgaris for four variants: CYP21A2 rs6474 (p.Arg102Lys) (P = 0.002); CYP21A2 rs6465 (P = 0.012); CYP19A1 rs8023263 (P = 0.037); and CYP19A1 rs2470152 (P = 0.007). Haplotype analyses showed that the distribution of CYP21A2 haplotypes was significantly associated with male patients, while no association of CYP19A1 haplotypes was observed. The structure of the human CYP21A2 consists of two substrate binding sites and one substrate access channel.
UNASSIGNED: This study shed a light on a potentially important effect of CYP21A2 and CYP19A1 genes in severe acne vulgaris in the Han Chinese, especially for male patients. Future studies using independently verified datasets from a broader geographical spectrum will be valuable in identifying the causal and functional variants responsible for severe acne vulgaris within the CYP19A1 and CYP21A2 genes.

BACKGROUND: 5-aminolevulinic acid mediated photodynamic therapy (ALA-PDT) is increasingly used to control severe acne. However, its impact on skin microbiota remains uncertain.
OBJECTIVE: We aimed to compare the makeup, diversity, and function of the microbiota in pilosebaceous units of patients with severe acne before and after ALA-PDT.
METHODS: A longitudinal cohort study was performed on 11 participants with severe facial acne. All patients were given 5%ALA-PDT every two weeks for three sessions in total. The contents of lesions were sampled for metagenomic sequencing at baseline and two weeks after the first ALA-PDT session.
RESULTS: Cutibacterium acnes was the most dominant species followed by Staphylococcus epidermidis and Pseudomonas fluorescens. Treatment with ALA-PDT led to clinical improvements in acne severity concurrent with a significant reduction in the relative abundance of C. acnes, while P. fluorescens increased significantly after ALA-PDT. No significant change was identified in other species. ALA-PDT administration was associated with an increased microbiota diversity and reductions in the relative abundance of the functional genes involved in energy metabolism and DNA replication.
CONCLUSIONS: ALA-PDT plays a therapeutic role by killing C. acnes, increasing P. fluorescens and the microbiome diversity, while inhibiting the function of microbiota in pilosebaceous units of severe acne.

OBJECTIVE: Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome encompasses heterogeneous dermatological manifestations, mainly palmoplantar pustulosis (PPP) and severe acne (SA). This study aims to explore the necessity of stratified management according to skin lesions.
METHODS: In a cohort of SAPHO patients, we compared the demographic, clinical, and scintigraphic characteristics of the SAPHO patients whose skin lesion was PPP or SA.
RESULTS: A total of 249 patients were included (227 affected by PPP and 22 affected by SA). Patients with SA were younger at onset (20, interquartile ranges (IQR) 15-30 vs. 37, IQR 30-46 years old; p < 0.001) and enrollment (35, IQR 25-38 vs. 41, IQR 33-50 years old; p = 0.001), and they had a prolonged disease duration (88.5 months, IQR 18.7-216.0 vs. 16.0, IQR 7.0-48.0 months; p < 0.001) and time needed for diagnosis (7.5, IQR 2.0-19.0 vs. 1.0, IQR 1.0-4.0 years; p < 0.001). Adjusted by age, sex, and disease duration, SA was significantly associated with more disease-modifying anti-rheumatic drug (DMARD) use (adjusted odds ratio (OR) 3.72; 95% confidence interval (CI) 1.23, 12.62; p = 0.019) and more sternoclavicular joint involvement (adjusted OR 5.91; 95% CI 1.17, 61.3; p = 0.030) in two separate Firth\'s logistic regression models.
CONCLUSIONS: SAPHO patients affected by PPP or SA as the only skin lesion may have different epidemiologic features, osteoarticular manifestations, and treatment history.Key Points• SAPHO patients with PPP or SA were heterogenous in both demographic, clinical, and imaging features.• SAPHO patients with SA were mainly male and had a significantly younger age and longer duration of symptoms before diagnosis.• SA in SAPHO patients was significantly associated with more sternoclavicular involvement and more DMARD use history.

BACKGROUND: Photodynamic therapy (PDT) with 5-aminolevulinic acid (ALA) has been described as an effective treatment for severe acne. However, very little evidence exists on the optimal concentration of ALA used in PDT for severe acne.
OBJECTIVE: To compare the efficacy and safety of PDT with 5% ALA vs 10% ALA in severe acne.
METHODS: Twenty-three patients with severe facial acne were randomly assigned to receive PDT with 5% ALA or 10% ALA on the left or right side of the face. Four PDT sessions were conducted with a light dose of 96 J/cm2 . The reduction rates of lesion counts between the two groups were compared at the week-4 and week-12 follow-up visits. Effective rate at the week-12 visit was the primary clinical outcome. Pain and other side effects were evaluated at each visit.
RESULTS: The decrease in inflammatory lesions in the 10% ALA group was greater than that in the 5% ALA group at both week-4 (79.2% vs 62.5%, P = 0.009) and week-12 follow-up visits (88.5% vs 78.3%, P = 0.018), while the decrease in noninflammatory lesion counts between the two groups was not statistically significant at each follow-up visit. The effective rate in the 10% ALA group was significantly higher than that in the 5% ALA group (95.7% vs 69.6%, P = 0.02). No significant difference was observed in pain scores between the two groups except in the first treatment session.
CONCLUSIONS: Photodynamic therapy using 10% ALA was more effective for severe acne than PDT using 5% ALA.

Acne is a common skin disease in adolescence. It is a chronic inflammatory disease of the pilosebaceous units, which mainly occurs on the face and upper parts of the trunk. Based on severity of the lesions, acne can be mild, moderate or severe. Severe acne is usually featured with a protracted course and residual scars. Photodynamic therapy (PDT) has been demonstrated to be effective in severe acne recently. We report a case of monozygotic twins with severe acne who were successfully treated with PDT.