Insulin-like growth factor-I gene polymorphism in acne vulgaris

Acromegaly presented with acne vulgaris: a retrospective study with 123 cases

BACKGROUND

Acne vulgaris is a prevalent skin condition. We have found that some acromegaly patients have acne. However, no study has examined the relationship between acromegaly and acne.

OBJECTIVE

To explore prevalence and correlation of adult acne in patients with acromegaly.

METHODS

For this cross-sectional study, we collected questionnaires, clinical information, and laboratory test results of acromegaly patients from January 2022 to December 2022 at Huashan Hospital. Of the 133 questionnaires returned, 123 had valid responses.

RESULTS

Of the 123 patients with acromegaly enrolled in this study, 54.5% had adult acne. No statistically significant difference was found in prevalence between male and female patients. 61.2% of adult acne patients reported late-onset acne. Late-onset acne patients first developed acne years before acromegaly diagnosis (mean of 5.6 years for male and 4.5 years for female patients). Some acne patients have received traditional anti-acne treatment. Moreover, 31% of the patients reported no improvement, and only 3.5% of patients claimed complete resolution of acne after treatment. Before acromegaly treatment, the prevalence of adult acne was 51.2%, with mild acne accounting for 73.0%, moderate acne accounting for 23.8%, and severe acne accounting for 3.2%. After acromegaly treatment, the prevalence of adult acne was significantly decreased to 37.4% (P = 0.007). An overall decrease in acne severity was noted, with 93.5%, 6.5%, and 0% having mild, moderate, and severe acne, respectively. A total of 83.6% of the patients had self-assessed acne remission, and 33.3% of the patients reported complete acne resolution. However, 9.0% of patients reported that their condition had worsened after acromegaly treatment. After treatment, GH, IGF-1, IGF-1 index, insulin levels, and HOMA-IR decreased significantly in all patients with acromegaly (P < 0.05). Acne remission correlated positively with IGF-1 levels, but not with GH levels. The relationship between acromegaly and acne remains to be elucidated.

CONCLUSIONS

Our findings provide preliminary evidence of the high prevalence of adult acne in acromegaly patients, and a high rate of late-onset acne as well. Traditional anti-acne treatments are less effective. Acne could be considerably relieved by treating acromegaly. Acne remission positively correlated with IGF-1 decline as well, which revealed the correlation between acne and IGF-1.

Exploring Acne Treatments: From Pathophysiological Mechanisms to Emerging Therapies

Acne vulgaris is a common dermatological condition that can present across different ages but predominantly affects adolescents and young adults. Characterized by various lesion types, the pathogenesis of acne is complex, involving genetic, hormonal, microbial, and inflammatory factors. This review comprehensively addresses current and emerging acne management strategies, emphasizing both topical and systemic treatments, procedural therapies, and dietary modifications. Key topical agents include retinoids, benzoyl peroxide, antibiotics, and other specialized compounds. Systemic options like antibiotics, hormonal therapies, and retinoids offer significant therapeutic benefits, particularly for moderate to severe cases. Procedural treatments such as laser devices, photodynamic therapy, chemical peels, and intralesional injections present viable alternatives for reducing acne symptoms and scarring. Emerging therapies focus on novel biologics, bacteriophages, probiotics, and peptides, providing promising future options. This review underscores the importance of personalized approaches to treatment due to the multifaceted nature of acne, highlighting the potential of innovative therapies for improving patient outcomes.

Genetic Variants Associated with Acne Vulgaris

Acne vulgaris (AV) ranks among the common chronic inflammatory disorders that impact the sebaceous components of hair follicles. Acne vulgaris is characterised by cardinal manifestations such as the presence of pimples, nodules, pustules, and cysts, which have the potential to lead to the development of acne scarring and pigmentation. The phenomenon is influenced by polygenic inheritance or can be ascribed to the interplay between multiple genes and environmental factors. In recent years, some researchers have found that some genes (such as IL, TNF, RETN, CYP family, MMPs and TIMPs genes et al) are associated with acne vulgaris and may affect the progression and prognosis of the disease. The number of reviews addressing acne-associated genetic variants, however, is limited. In that case, we have compiled a list of prevalent genes associated with acne in recent times. This helps us understand acne's genetic basis and lets us step in early for people prone to severe acne, lowering the chance of acne scars.

Metabolic and Dietary Factors in Acne Vulgaris and Evaluation of the Acne Vulgaris Treatment with Oral Contraceptive-Based Therapies in Young Adult Women

The etiopathogenesis of acne is complex, as several endo- and exogenous factors that affect the sebaceous-hair unit are involved in the development of acne lesions. The main aim of the study was to evaluate selected metabolic parameters before treatment. Another goal of the study was to determine the correlation between selected metabolic and dietary parameters and the severity of acne before treatment. The third objective was to assess the severity of acne before and after treatment, considering the type of treatment used. The final objective was to assess the relationship between the difference in acne severity before and after treatment, considering the type of treatment used and factors of dairy or sweets intake. 168 women participated in the study. The patients belonged to two groups: the study group (99 patients with acne vulgaris) and the control group (69 patients without skin lesions). The study group was divided into subgroups according to the treatment used: contraceptive preparation, contraceptive preparation and cyproterone acetate, and contraceptive preparation and isotretinoin preparation. We found that LDL levels and consumption of sweets correlated with acne severity. The mainstay of acne treatment is contraceptive treatment (ethinylestradiol and drospirenone). The effectiveness of the three contraceptive-based treatments was confirmed by observing the severity of acne. There were no significant correlations between the difference in acne severity before and after treatment with the three treatments and factors of dairy or sweet consumption.

Acne Vulgaris and Metabolic Syndrome: A Possible Association

Introduction

Acne vulgaris is an androgen-dependent disorder with excessive sebum production and proliferation of Propionibacterium acnes. Metabolic syndrome (MetS) is a multisystem disorder that increases the risk of diabetes mellitus, stroke, and cardiovascular diseases. ​This study aims to analyze the association of MetS with acne vulgaris.

Methods

A cross-sectional study was conducted with 65 cases of acne vulgaris and 65 age and sex-matched controls. We used the system provided by the Indian authors for grading acne according to the clinical severity. In addition, the criteria updated according to the joint consensus of 2009 were employed for the diagnosis of MetS.

Results

On clinical examination, grade 2 was the most prevalent grade of acne. We observed an increased incidence of abnormal waist circumference, triglyceride, HDL, and fasting blood glucose among the cases (p<0.05). Consequently, an increased occurrence of MetS was observed in the case group (p=0.011). While comparing the mean values of the parameters, we noted a significant difference in terms of waist circumference and HDL values. An increased mean value of waist circumference was noted in the case group while an increased mean value of HDL was reported from the control group (p<0.05). 

Conclusion

Patients with acne vulgaris have a greater chance of developing MetS. Hence, an in-depth examination of clinical, anthropometric, and biochemical parameters that may lead to the development of MetS is necessary.

Gene variants associated with acne vulgaris presentation and severity: a systematic review and meta-analysis

BACKGROUND

Multiple factors have been attributed to acne vulgaris predisposition and individual variations in the severity of skin symptoms, and genetics stood out as one of the major factors.

METHODS

We performed a systematic review on the genes and their variants that have been investigated for association with acne presentation and severity. A random-effect meta-analysis using the allele model (minor allele vs. major allele) was also conducted to provide an overall estimation of risk effects of frequently reported gene variants. This included a subset data of 982 acne cases and 846 controls extracted from our existing GWAS database on various allergic and skin diseases among Singapore Chinese.

RESULTS

Systematic review of 51 articles covering Asians and Caucasians found 60 genes/loci and their 100 variants implicated in acne; majority of them were in the intron, coding region/missense, and promoter regions. The commonly studied candidate genes/gene families include tumor necrosis factor (TNF), and the interleukin (IL) and cytochrome P450 (CYP) gene families. Our meta-analysis showed that most of the analyzed gene variants exhibited insignificant pooled odds ratio (pOR) and significant heterogeneity between studies. Nevertheless, we found that TNF rs1800629 A allele carriers and CYP17A1 rs743572 T allele carriers had significantly reduced mild acne risk [pOR: 0.60; 95% Confidence Interval (CI): 0.33-0.86] and severe acne risk (pOR: 0.59; 95% CI: 0.40-0.79), respectively, across populations. Overall, FST (follistatin) rs629725 A allele poses a significantly modest increased risk for acne presentation (pOR: 1.19, 95% CI: 1.14, 1.23), but neither TIMP2 (TIMP metallopeptidase inhibitor 2) rs8179090 nor CYP1A1 rs4646903 (pOR: 0.96, 95% CI: 0.80-1.12; pOR: 0.95, 95% CI: 0.83, 1.08), respectively. We discovered 15 novel SNPs in the 3' UTR region of the Toll-like Receptor 4 gene (TLR4) associated with acne presentation.

CONCLUSIONS

This systematic review and meta-analysis suggest that genes influencing inflammatory responses, specifically TNF, and genes influencing the function and activity of sebaceous glands, specifically CYP17A1 and FST, have potential risk variants for acne presentation and severity across populations. Understanding the genetic susceptibility factors and biological pathways involved in the pathogenesis of acne will help us to gain insights into developing effective acne treatments.

Association Between Adult Acne and Dietary Behaviors: Findings From the NutriNet-Santé Prospective Cohort Study

Importance

Acne is a chronic, multifactorial inflammatory disease. The association between consumption of dairy products and fatty and sugary foods and occurrence and progression of acne remains unclear.

Objective

To assess the association between dietary behavior and current acne in adults.

Design, Setting, and Participants

A cross-sectional study was performed as part of the NutriNet-Santé study, which is an ongoing observational, web-based cohort study that was launched in France in May 2009. The present study was conducted from November 14, 2018, to July 8, 2019. A total of 24 452 participants completed an online self-questionnaire to categorize their acne status: never acne, past acne, or current acne. Associations between dietary behavior (food intake, nutrient intake, and the dietary pattern derived from a principal component analysis) and current or past acne were studied in multinomial logistic regression models adjusted for potential confounding variables (age, sex, physical activity, smoking status, educational level, daily energy intake, number of dietary records completed, and depressive symptoms).

Results

The 24 452 participants (mean [SD] age, 57 [14] years; 18 327 women [75%]) completed at least 3 dietary records. Of these, 11 324 individuals (46%) reported past or current acne. After adjustment, there was a significant association between current acne and the consumption of fatty and sugary products (adjusted odds ratio [aOR], 1.54; 95% CI, 1.09-2.16), sugary beverages (aOR, 1.18; 95% CI, 1.01-1.38), and milk (aOR, 1.12; 95% CI, 1.00-1.25). An energy-dense dietary pattern (high consumption of fatty and sugary products) was associated with current acne (aOR, 1.13; 95% CI, 1.05-1.18).

Conclusions and Relevance

In this study, consumption of milk, sugary beverages, and fatty and sugary products appeared to be associated with current acne in adults. Further large-scale studies are warranted to investigate more closely the associations between diet and adult acne.

The Insulin-like Growth Factor-1 (G>A) and 5,10-methylenetetrahydrofolate Reductase (C677T) Gene Variants and the Serum Levels of Insulin-like Growth Factor-1, Insulin, and Homeostasis Model Assessment in Patients with Acne Vulgaris

Background & Objective

To find an association between gene variants of insulin-like growth factor-1 (IGF-1) and 5,10-methylenetetrahydrofolate reductase (MTHFR) with the risk of acne vulgaris (AV).

Methods

In a case-control study, we investigated 150 AV patients and 148 healthy individuals (aged 18-25 years) for the IGF-1 G>A and MTHFR C677T polymorphisms, as well as the serum levels of IGF-1, insulin, and the homeostasis model assessment of insulin resistance (HOMA-IR). The serum biochemical parameters and the genotypes of IGF-1 G>A and MTHFR C677T were detected by using appropriate kits and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods, respectively.

Results

The frequencies of IGF-1 and the MTHFR polymorphisms were not significantly different comparing patients and controls. The serum level of IGF-1 was 179.8±72.8 µg/L in AV patients compared to 164.6±63.7 µg/L in controls (P=0.056). The serum level of insulin in female patients was significantly higher than controls. The HOMA was 3.54±5.6 in patients compared to 1.16±1.4 (P<0.001) in controls. Significantly higher levels of fasting blood sugar (FBS), total cholesterol, and low-density lipoprotein-cholesterol (LDL-C) were detected in female patients than controls. However, the level of estradiol was significantly lower in female patients than in controls. In females, the presence of the MTHFR T allele was associated with significantly higher levels of FBS and LDL-C, as well as a significantly lower level of estradiol compared to those carriers of the C allele.

Conclusion

We found the absence of an association between IGF-1 and MTHFR polymorphisms with the risk of AV. However, increased insulin, IGF-1, and HOMA levels in AV patients indicated the effect of insulin and insulin resistance in the risk of AV and its severity.

Role of insulin-like growth factor-1 in skin tags: a clinical, genetic and immunohistochemical study in a sample of Egyptian patients

Background: Skin tags (STs) are benign connective tissue neoplasms, in which insulin-like growth factor −1 (IGF-1) has a mitogenic and antiapoptotic activity.

Purpose: We aimed to study for the first time, the possible role of IGF-1 (CA) 19 and rs6214 gene polymorphisms, and its tissue immunoreactivity in the pathogenesis of STs.

Patients and methods: This case–control study included 40 ST patients and 20 controls. We searched for (CA) 19 single-nucleotide polymorphism (SNP) using conversional PCR and for rs6214 gene polymorphism using real-time PCR. IGF-1 tissue immunoreactivity was investigated using polyclonal IGF-1 antibody.

Results: IGF-1 immunoreactivity showed significantly strong upregulation in epidermis (p=0.002) and dermal components (endothelial cells [p=0.038] and fibroblasts [p=0.004]) of excised STs than control skin. TT and CT rs6214 genotypes and its T allele were significantly associated with STs (p=0.006 and P=0.002, respectively). Also (<192 bp) and 192–194 bp (CA) 19 genotypes were significantly predominant in ST patients than controls (p=0.013). These 4 genotypes were significantly associated with development of multiple STs and epidermal IGF-1 tissue immunoreactivity in studied patients.

Conclusions: IGF-1 (CA) 19 and rs6214 gene polymorphisms may contribute to a predisposition of STs in Egyptian patients, the role of which could be mediated through local upregulation of IGF-1 in cutaneous tissues.

Association of interleukin-6 gene promoter polymorphism with acne vulgaris and its severity

BACKGROUND

Acne vulgaris (AV) is an inflammatory disorder with a possible genetic background. Different cytokines and mediators are involved in its pathogenesis.

AIM

Our aim was to investigate the interleukin (IL)-6 572 polymorphism in patients with AV and its relation to patient sex and acne severity.

METHODS

In total, 30 patients with acne and 20 healthy controls (HCs) were enrolled. The Global Acne Grading System was used to assess acne severity. The IL-6 572 gene promoter polymorphism was assessed using the PCR-restriction fragment length polymorphism method.

RESULTS

There was a significantly higher association of IL-6 572 variants genotypes in patients with acne (93%) compared with the HC group (45%) (P < 0.001), with a higher incidence of the IL-6 572 CC polymorphism in patients with acne. A significant difference (P < 0.001) between C and G alleles in patients vs. HCs was detected. There were no significant associations between the IL-6 572 variant genotypes and either patient sex or AV severity.

CONCLUSION

IL-6 gene promoter polymorphism might have a role in AV susceptibility but it is not related to AV severity.

Dairy Intake and Acne Vulgaris: A Systematic Review and Meta-Analysis of 78,529 Children, Adolescents, and Young Adults

A meta-analysis can help inform the debate about the epidemiological evidence on dairy intake and development of acne. A systematic literature search of PubMed from inception to 11 December 2017 was performed to estimate the association of dairy intake and acne in children, adolescents, and young adults in observational studies. We estimated the pooled random effects odds ratio (OR) (95% CI), heterogeneity (I²-statistics, Q-statistics), and publication bias. We included 14 studies (n = 78,529; 23,046 acne-cases/55,483 controls) aged 7⁻30 years. ORs for acne were 1.25 (95% CI: 1.15⁻1.36; p = 6.13 × 10^-8) for any dairy, 1.22 (1.08⁻1.38; p = 1.62 × 10^-3) for full-fat dairy, 1.28 (1.13⁻1.44; p = 8.23 × 10^-5) for any milk, 1.22 (1.06⁻1.41; p = 6.66 × 10^-3) for whole milk, 1.32 (1.16⁻1.52; p = 4.33 × 10^-5) for low-fat/skim milk, 1.22 (1.00⁻1.50; p = 5.21 × 10^-2) for cheese, and 1.36 (1.05⁻1.77; p = 2.21 × 10^-2) for yogurt compared to no intake. ORs per frequency of any milk intake were 1.24 (0.95⁻1.62) by 2⁻6 glasses per week, 1.41 (1.05⁻1.90) by 1 glass per day, and 1.43 (1.09⁻1.88) by ≥2 glasses per day compared to intake less than weekly. Adjusted results were attenuated and compared unadjusted. There was publication bias (p = 4.71 × 10^-3), and heterogeneity in the meta-analyses were explained by dairy and study characteristics. In conclusion, any dairy, such as milk, yogurt, and cheese, was associated with an increased OR for acne in individuals aged 7⁻30 years. However, results should be interpreted with caution due to heterogeneity and bias across studies.

Akne

Akne ist eine chronische Erkrankung mit hoher Prävalenz unter Jugendlichen. Pathogenetische Hauptfaktoren (und ihre klinischen Korrelate) sind gesteigerte Talgproduktion (Seborrhoe), follikuläre Hyperkeratose (Komedonen) und perifollikuläre Entzündungsvorgänge (Papulopusteln). Die Krankheit wird von endogenen (Androgene, IGF-1, neuroendokrine Faktoren) und exogenen (Propionibacterium acnes, Diät, mechanische Irritation, Inhaltsstoffe medizinischer oder kosmetischer Externa) Einflüssen moduliert. Akne geht mit zum Teil hoher Morbidität einher und kann bereits bei leichter Ausprägung eine erhebliche Verschlechterung der Lebensqualität bewirken. Zu Therapie stehen wirksame topische und systemische Behandlungsverfahren zur Verfügung. Eine optimale Behandlung erfordert eine stadiengerechtes Management und kontinuierliche ärztliche Begleitung der Patienten über den erforderlichen Behandlungszeitraum.

Heritability and GWAS Analyses of Acne in Australian Adolescent Twins

Acne vulgaris is a skin disease with a multifactorial and complex pathology. While several twin studies have estimated that acne has a heritability of up to 80%, the genomic elements responsible for the origin and pathology of acne are still undiscovered. Here we performed a twin-based structural equation model, using available data on acne severity for an Australian sample of 4,491 twins and their siblings aged from 10 to 24. This study extends by a factor of 3 an earlier analysis of the genetic factors of acne. Acne severity was rated by nurses on a 4-point scale (1 = absent to 4 = severe) on up to three body sites (face, back, chest) and on up to three occasions (age 12, 14, and 16). The phenotype that we analyzed was the most severe rating at any site or age. The polychoric correlation for monozygotic twins was higher (r MZ = 0.86, 95% CI [0.81, 0.90]) than for dizygotic twins (r DZ = 0.42, 95% CI [0.35, 0.47]). A model that includes additive genetic effects and unique environmental effects was the most parsimonious model to explain the genetic variance of acne severity, and the estimated heritability was 0.85 (95% CI [0.82, 0.87]). We then conducted a genome-wide analysis including an additional 271 siblings - for a total of 4,762 individuals. A genome-wide association study (GWAS) scan did not detect loci associated with the severity of acne at the threshold of 5E-08 but suggestive association was found for three SNPs: rs10515088 locus 5q13.1 (p = 3.9E-07), rs12738078 locus 1p35.5 (p = 6.7E-07), and rs117943429 locus 18q21.2 (p = 9.1E-07). The 5q13.1 locus is close to PIK3R1, a gene that has a potential regulatory effect on sebocyte differentiation.

Genetic architecture of acne vulgaris

Acne vulgaris is a ubiquitary skin disease characterized by chronic inflammation of the pilosebaceous unit resulting from bacterial colonization of hair follicles by Propionibacterium acnes, androgen-induced increased sebum production, altered keratinization and inflammation. Here, we review our current understanding of the genetic architecture of this intriguing disease. We analysed genomewide association studies (GWAS) and candidate genes studies for acne vulgaris. Moreover, we included GWAS studies for the associated disease polycystic ovary syndrome (PCOS). Overall, the available data revealed sixteen genetic loci flagged by single nucleotide polymorphisms (SNPs), none of which has been confirmed yet by independent studies. Moreover, a GWAS for PCOS identified 21 susceptible loci. The genetic architecture is complex which has been revealed by GWAS. Further and larger studies in different populations are required to confirm or disprove results from candidate gene studies as well to identify signals that may overlap between different populations. Finally, studies on rare genetic variants in acne and associated diseases like PCOS may deepen our understanding of its pathogenesis.

The possible role of diet in the pathogenesis of adult female acne

Acne in adults is a chronic, increasingly common disease, especially among women. It differs in pathogenesis and clinical presentation from adolescent acne. Acne in adults is associated with Western diet, defined as high consumption of milk, high glycemic load and high calorie intake. Metabolic signals of this diet result in a significant increase in insulin/insulin growth factor 1 serum level and consequently in the molecular interplay of mammalian target of rapamycin complex 1 kinase (mTORC1)/forkhead box protein 1 (FoxO1) mediated nutrient signaling, leading to increased proliferation of keratinocytes, increased lipogenesis and sebum production and finally to aggravation of acne.

Survivin as a Novel Biomarker in the Pathogenesis of Acne Vulgaris and Its Correlation to Insulin-Like Growth Factor-I

Survivin, a member of the inhibitor of apoptosis protein family, has an important role in cell cycle regulation. Insulin-like growth factor-I (IGF-I) is a polypeptide hormone with wide range of biologic effects including stimulation of lipogenesis in sebaceous glands. Their overexpression in some fibrotic disorders suggests a possible implication of both IGF-I and survivin in the pathogenesis of acne and/or acne scars. The current study aimed to assess and correlate serum levels of IGF-I and survivin in patients with active acne vulgaris and postinflammatory acne scars and to evaluate their lesional expressions in comparison to healthy controls. Serum IGF-I and survivin were estimated using commercially available ELISA kits and their tissues expressions were investigated using Western blotting. Our findings suggest that IGF-I and survivin could play potential roles in the pathogenesis of active acne vulgaris and more importantly in postinflammatory acne scars with significant positive correlation coefficient between serum levels of IGF-I and survivin which support IGF-I-/PI3K-/AKT-mediated downregulation of nuclear expression of FoxO transcription factors resulting in enhanced survivin expression.

Polymorphisms in the cytochrome P-450 (CYP) 1A1 and 17 genes are not associated with acne vulgaris in the Polish population

Introduction

The pathogenesis of acne is complex, multifactorial and not well understood. The genetic background of this dermatosis is well documented.

Aim

To assess the frequency of –34 T > C single nucleotide polymorphism in the promoter of the CYP17 gene as well as m1 (+6,235 T > C) and m2 (+4,889 A > G) mutation in the coding region CYP1A1 gene acne patients from the Northern Polish population.

Material and methods

The study included 115 acne patients and 94 healthy controls (aged over 20) without acne in anamnesis. The CYP1A1 polymorphism was analyzed by polymerase chain reaction (PCR). The restriction fragment length polymorphism (RFLP) was used to analyze m1 mutation and allele-specific PCR in the case of m2 mutation. The CYP17 polymorphism was analyzed by RFLP. The results were evaluated by the Pearson's χ² test.

Results

There were no statistically significant associations between allele and genotype frequencies between the acne and the control group.

Conclusions

We did not confirm the role of the CYP1A1 and CYP17 gene as predictor factors for acne development in the Polish population.

Acne vulgaris

Acne vulgaris is a chronic inflammatory disease - rather than a natural part of the life cycle as colloquially viewed - of the pilosebaceous unit (comprising the hair follicle, hair shaft and sebaceous gland) and is among the most common dermatological conditions worldwide. Some of the key mechanisms involved in the development of acne include disturbed sebaceous gland activity associated with hyperseborrhoea (that is, increased sebum production) and alterations in sebum fatty acid composition, dysregulation of the hormone microenvironment, interaction with neuropeptides, follicular hyperkeratinization, induction of inflammation and dysfunction of the innate and adaptive immunity. Grading of acne involves lesion counting and photographic methods. However, there is a lack of consensus on the exact grading criteria, which hampers the conduction and comparison of randomized controlled clinical trials evaluating treatments. Prevention of acne relies on the successful management of modifiable risk factors, such as underlying systemic diseases and lifestyle factors. Several treatments are available, but guidelines suffer from a lack of data to make evidence-based recommendations. In addition, the complex combination treatment regimens required to target different aspects of acne pathophysiology lead to poor adherence, which undermines treatment success. Acne commonly causes scarring and reduces the quality of life of patients. New treatment options with a shift towards targeting the early processes involved in acne development instead of suppressing the effects of end products will enhance our ability to improve the outcomes for patients with acne.

Linking diet to acne metabolomics, inflammation, and comedogenesis: an update

Acne vulgaris, an epidemic inflammatory skin disease of adolescence, is closely related to Western diet. Three major food classes that promote acne are: 1) hyperglycemic carbohydrates, 2) milk and dairy products, 3) saturated fats including trans-fats and deficient ω-3 polyunsaturated fatty acids (PUFAs). Diet-induced insulin/insulin-like growth factor (IGF-1)-signaling is superimposed on elevated IGF-1 levels during puberty, thereby unmasking the impact of aberrant nutrigenomics on sebaceous gland homeostasis. Western diet provides abundant branched-chain amino acids (BCAAs), glutamine, and palmitic acid. Insulin and IGF-1 suppress the activity of the metabolic transcription factor forkhead box O1 (FoxO1). Insulin, IGF-1, BCAAs, glutamine, and palmitate activate the nutrient-sensitive kinase mechanistic target of rapamycin complex 1 (mTORC1), the key regulator of anabolism and lipogenesis. FoxO1 is a negative coregulator of androgen receptor, peroxisome proliferator-activated receptor-γ (PPARγ), liver X receptor-α, and sterol response element binding protein-1c (SREBP-1c), crucial transcription factors of sebaceous lipogenesis. mTORC1 stimulates the expression of PPARγ and SREBP-1c, promoting sebum production. SREBP-1c upregulates stearoyl-CoA- and Δ6-desaturase, enhancing the proportion of monounsaturated fatty acids in sebum triglycerides. Diet-mediated aberrations in sebum quantity (hyperseborrhea) and composition (dysseborrhea) promote Propionibacterium acnes overgrowth and biofilm formation with overexpression of the virulence factor triglyceride lipase increasing follicular levels of free palmitate and oleate. Free palmitate functions as a "danger signal," stimulating toll-like receptor-2-mediated inflammasome activation with interleukin-1β release, Th17 differentiation, and interleukin-17-mediated keratinocyte proliferation. Oleate stimulates P. acnes adhesion, keratinocyte proliferation, and comedogenesis via interleukin-1α release. Thus, diet-induced metabolomic alterations promote the visible sebofollicular inflammasomopathy acne vulgaris. Nutrition therapy of acne has to increase FoxO1 and to attenuate mTORC1/SREBP-1c signaling. Patients should balance total calorie uptake and restrict refined carbohydrates, milk, dairy protein supplements, saturated fats, and trans-fats. A paleolithic-like diet enriched in vegetables and fish is recommended. Plant-derived mTORC1 inhibitors and ω-3-PUFAs are promising dietary supplements supporting nutrition therapy of acne vulgaris.

Treatment of acne in children

Acne is a common skin condition in adolescents. It is not uncommon in childhood and it persists into adulthood. A broad range of acne treatments are available and have been shown to be safe and effective in adolescents and adults. However, there is limited literature regarding acne treatment in childhood and its available therapeutic options. It seems reasonable to extrapolate findings of the various studies reported on treatment of acne in the adolescent and adult age group, with the exclusion of the use of tetracycline derivatives. As clinicians, we must be more familiar with the clinical presentation of acne and available treatment options in our younger patients. Early recognition of acne with prompt and appropriate initiation of therapy in childhood will help prevent severe scarring in children.